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1
Sun, Weiguo. "Contributions to palaeontology and stratigraphic correlation of the late precambrian in China and Australia /." Title page, contents and summary only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09phs957.pdf.
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Krueger, Diane M. "Conodont biostratigraphy of middle and upper Ordovician rocks in the Ouachita Mountains of Arkansas and Oklahoma /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3052190.
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3
Klug, Christopher Allen. "Lower Permian through Lower Trassic [sic] paleontology, stratigraphy, and chemostratigraphy of the Bilk Creek Mountains of Humboldt County, Nevada." Bowling Green, Ohio : Bowling Green State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=bgsu1184878826.
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Baghiyan-Yazd, Mohammad Hassan. "Palaeoichnology of the terminal Proterozoic-Early Cambrian transition in central Australia : interregional correlation and palaeoecology." Title page, table of contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phb1445.pdf.
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May, Geoffrey. "Oligocene to recent evolution of the Calama Basin, northern Chile." Thesis, University of Aberdeen, 1997. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=191900.
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The Calama and eastern Pampa del Tamarugal Basins are located between 22°S and 23°S within the forearc of northern Chile. They are filled by sediments deposited in alluvial braidplain, fluvial, playa sandflat, lacustrine and volcaniclastic environments under a semi-arid to hyper-arid climate. The nature of the alluvial braidplain depositional environment is unusual in that it combines elements of both alluvial fan and fluvial depositional systems, in contradiction to recently published models of alluvial fan sedimentation. Detailed sedimentary logging, magnetostratigraphy and dating of 14 volcanic interbeds by the 40Ar/39Ar laser fusion method has established a lithostratigraphic and chronostratigraphic framework for the 700 m thick basin-fill. Basin formation was investigated by regional subsidence during the Late Eocene or Early Oligocene, followed by widespread alluvial braidplain deposition during the Oligocene(?). A change to fluvial and playa sandflat deposition during the Early to Mid-Miocene is considered to be coincident with a decrease in active subsidence. Sedimentation ceased and thick (25 m) gypcrete deposits developed along the eastern margin of the basin during the Mid-Miocene as a response to an increasingly arid climate. Phases of minor lacustrine, fluvial and alluvial braidplain deposition during the Late Miocene-Early-Pliocene and the Late Pliocene(?) to Pleistocene were primarily controlled by small-scale fault movements and folding events, although climatic variations may have been important in some cases. A new lithostratigraphic division of the basin-fill is proposed here, which comprises 13 different formations. The previously defined El Loa Formation comprises a number of depositional units which are spatially and temporally discrete formations, and is therefore awarded group status.
6
Eifert, Tambra L. "The Cretaceous-Paleogene transition in the northern Mississippi Embayment, S.E. Missouri: palynology, micropaleontology, and evidence of a mega-tsunami deposit." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2009. http://scholarsmine.mst.edu/thesis/pdf/Eifert_09007dcc80658622.pdf.
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Thesis (Ph. D.)--Missouri University of Science and Technology, 2009.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed May 4, 2009) Includes bibliographical references (p. 243-265).
7
Sessa, Jocelyn A. "The dynamics of rapid, asynchronous biotic turnover in the middle Devonian Appalachian basin of New York : a thesis /." Connect to The dynamics of rapid, asynchronous biotic turnover in the middle Devonian Appalachian basin of New York (Online), 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=1054576413.
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Shen, Jian-Wei. "Effects of differing tectono-stratigraphic settings on late Devonian and early carboniferous reefs, Western Australia, Eastern Australia, South China, and Japan /." St. Lucia, Qld, 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17417.pdf.
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Faria, Rafael Souza de 1985. "Licofitas Guadalupianas da Bacia do Parana : Novos dados morfo-anatomicos." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/287313.
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Orientador: Fresia Soledad Ricardi-BrancoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociencias
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Resumo: Lycopodiopsis derbyi é a espécie à qual mais comumente se relacionam os fragmentos caulinares licofíticos encontrados em estratos guadalupianos da Bacia do Paraná. Tipicamente caracteriza-se por um cilindro vascular sifonostélico com o anel descontínuo cortado por raios medulares e pela presença de almofadas foliares rômbicas com vesícula infrafoliar e cicatrizes foliares sem sinais de páricnos. Microfilos fragmentados geralmente ocorrem associados aos caules. Aqui foram tomadas três localidades no estado de São Paulo (de afloramentos da Formação Corumbataí), uma no estado do Paraná e uma em Santa Catarina (ambas de afloramentos da Formação Teresina) para as quais se estudaram os caules e microfilos de licófitas encontrados. Os caules foram diagnosticados como L. derbyi. Análises morfológicas levaram a sugestão de um possível modelo ontogenético relacionando as almofadas foliares e o diâmetro dos ramos. Nas análises anatômicas interpretou-se o córtex de maneira diferente a de autores anteriores. Com base nos dados adquiridos propõe-se uma emenda à diagnose da espécie e ainda sugere-se uma modificação da chave de identificação de Thomas e Meyen (1984) para as Lepidodendrales do Paleozóico superior. Para os microfilos definiu-se uma nova organo-espécie com base em amostras de Piracicaba (SP), Lepidophylloides corumbataensis. Tal organo-espécie é a primeira do gênero formalmente descrita para o Brasil e possivelmente para o Gondwana. Representa ainda o primeiro registro de tecido paliçádico numa espécie de Lepidphylloides. A organização dos fexies de xilema em forma de crescente sugere uma proximidade às espécies da Catásia. A íntima associação com Lycopodiopsis derbyi indica que provavelmente representem as folhas dos mesmos. Compararndo as ocorrências de microfilos estudadas nas formações Teresina e Corumbataí, concluiu-se que na primeira aqueles ocorrem r em menores concentrações e sem anatomia preservada, indicando maior transporte.
Abstract: Master degree dissertation Rafael Souza de Faria Lycopodiopsis derbyi is the most common species to which the lycopod stem fragments found in the Guadalupian strata from the Paraná Basin are assigned. A vascular cylinder represented by a siphonostele with a discontinuous ring crossed by medular rays and the presence of rhombic leaf cushions with infrafoliar bladders and leaf scars without any sign of pharichnos typically characterize the species. Fragmented microphylls occur in general associated with the stems. Here three localities in the state of São Paulo (from outcrops of Corumbataí Formation), one in Paraná state and one in Santa Catarina state (from outcrops of Teresina Formation) where lycopods stems and microphylls are found have been studied. The stems were diagnosed as L. derbyi. Morphological analyses suggest a possible ontogenetic model relating the leaf cushions to the branch diameter. In the anatomical analyses the cortex was interpreted differently from previous authors. Based on the data acquired an emended diagnoses is proposed for the species together with a modification of the Thomas and Meyen's (1984) identification key for the Upper Paleozoic Lepidodendrales. With regard to the microphylls, a new organo-species based on samples from Piracicaba (São Paulo state) was defined, Lepidophylloides corumbatensis. This organo-species is the first of the genus formally described for Brazil and probably for Gondwanaland. It also represents the first register of palisade tissue in a Lepidophylloides species. The xylem bundle organization in crescent shape suggests a close relation with the catasian species The association with Lycopodiopsis derbyi indicates that they represent the leaves of the such stems. Comparing the mycrophylls studied from the Teresina and Corumbataí formations, the ones occuring in the first are commonly in lower concentrations and with no preserved anatomy, indicating more transport.
Mestrado
Geologia e Recursos Naturais
Mestre em Geociências
10
Matos, José Esteves de. "Stratigraphy, sedimentation and oil potential of the Lower Jurassic to Kimmeridgian of the United Arab Emirates : outcrop and subsurface compared." Thesis, University of Aberdeen, 1997. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=120500.
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The Jurassic litho-biostratigraphy is reviewed and Jurassic depositional models are defined in order to clarify some regional stratigraphic uncertainties and to evaluate the hydrocarbon potential of the Jurassic of the United Arab Emirates (UAE). A thick succession of Triassic-Cretaceous shallow-marine carbonates is exposed in Wadi Naqab, southeast of Ras Al Khaimah in the UAE, Musandam Peninsula. The Jurassic, 1310 m thick, is examined using biostratigraphy, sedimentology and sequence stratigraphy and compared with the Abu Dhabi subsurface. Direct composition of the Jurassic foraminiferal biozones and algal assemblages can be made between Wadi Naqab and the South-Tethyan realm. Palynological data from the subsurface demonstrate that much of the Liassic, which is well represented in the Musandam Peninsula, is missing over most of the Emirates. A ca. 50 Ma time gap was defined within the Abu Dhabi clastic Minjur Formation (previously assigned to the Triassic). The age of the palynoflora of the upper Minjur is Bajocian, while the lower Minjur yielded Late Carnian palynomorphs. The Upper Toarcian and most of the Aalenian is also probably missing in the Musandam Peninsula, as in the subsurface of the Emirates and Saudi Arabia. A new Bajocian foraminifera Pseudodictyopsella jurassica, n. gen., n. sp., was recognised, and the inception of some stromatoporoids was earlier than previously thought. The Liassic of Wadi Naqab is dominantly a metre-scale 5th-order Milankovitch-driven succession composed of peritidal cycles. Cycle tops are commonly marked by corrosion zones and/or karsts. Stacked paleokarsts are found particularly in the Sinemurian and Lower Pliensbachian. In Wadi Naqab, the Middle and Upper Jurassic seem to comprise one shallowing-upward 3rd-order cycle built of abundant 5th-order cycles. As a result of comparisons in this study, the Bajocian Izhara Formation is redefined and a new type-section proposed. Most of the Kimmeridgian and Tithonian are absent in Wadi Naqab, and eastern onshore and offshore Abu Dhabi, as the result of uplift and erosion before deposition of the Lower Cretaceous. Possible major Jurassic (Liassic-Early Kimmeridgian) hydrocarbon plays of Abu Dhabi are: the Marrat lowstand wedge of eastern onshore, the Jurassic onlap of Triassic high blocks in offshore areas, the Minjur lowstand clastics, the offshore Uweinat and Upper Araej and the Upper Jurassic Hadriya and Hanifa reservoirs.
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Arthur, Andrew John. "Mesozoic stratigraphy and paleontology of the west side of Harrison Lake, southwestern British Columbia." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/27794.
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A well preserved, fossiliferous Middle Triassic to Early Cretaceous section lies on the west side of Harrison Lake in the southern Coast Mountains. The study of this area involves a re-evaluation of the stratigraphic nomenclature first described by Crickmay (1925, 1930a) together with a lithologic description of the units and age determinations based on collected, identified and described fossils by the writer. Discussions on the biostratigraphy, paleogeography, regional correlations and structure of the thesis area and an overview of the regional tectonics of southwestern British Columbia and northwestern Washington, help to better understand the relation of this Mesozoic section to other rock assemblages in this geologically complex region.
The oldest unit, the Middle Triassic Camp Cove Formation, comprises conglomeratic sandstone, siltstone and minor volcanic rock. Unconformable7 overlying this unit is the Toarcian to Early(?) Bajocian Harrison Lake Formation, divided into four distinct members by the writer, Celia Cove Member (basal conglomerate), West Road Member (siltstone, shale), Weaver Lake Member (flows, pyroclastic rocks, minor sediments) and Echo Island Member (interbedded tuff, siltstone, sandstone). Thickness of this formation is estimated at 3000 m. A hiatus probably is present between this unit and overlying shale, siltstone and sandstone of the Early Callovian Mysterious Creek Formation which is 700 m thick. Conformably above this are 230 m of sandstone and volcaniclastic rock of the Early Oxfordian Billhook Creek Formation. Late Jurassic fluvial conglomerate, sandstone and siltstone of the Kent Formation, perhaps 1000 m thick south of Harrison River, unconformably(?) overlies the last two units mentioned. Berriasian to Valanginian conglomerate and sandstone, 218 m thick, of the Peninsula Formation overlies the Billhook Creek Formation with slight angular unconformity. The Peninsula Formation is conformably overlain by tuffaceous sandstone, volcanic conglomerate, crystal tuff and flows of the Valanginian to Middle Albian Brokenback Hill Formation which is several km thick. Nine Jurassic ammonite genera are identified and described in this report. Triassic radiolaria and conpdonts and Cretaceous ammonites and bivalves are also present in the section.
The most significant structure in the thesis area is the post-Albian to pre-Late Eocene Harrison Fault which strikes north-northwest through Harrison Lake, separating the Mesozoic section along the west side from the northern extension of the Cascade Metamorphic Core on the east side of the lake. A strong sub-horizontal stretching lineation within the fault zone may indicate right-lateral strike-slip movement.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
12
Tremblay, James Vincent. "Trilobites and strata of the Lower and Middle Cambrian Peyto, Mount Whyte and Naiset Formations, Alberta and British Columbia /." *McMaster only, 1996.
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13
Schmidt, Rolf. "Eocene bryozoa of the St Vincent Basin, South Australia - taxonomy, biogeography and palaeoenvironments /." Title page, abstract and contents only, 2003. http://web4.library.adelaide.edu.au/theses/09PH/09phs3491.pdf.
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Thesis (Ph.D.)--University of Adelaide, School of Earth and Environmental Sciences, Discipline of Geology and Geophysics, 2003?Includes Publication list by the author as appendix A. "July 2003." Includes bibliographical references (leaves 308-324).
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Korotkikh, Elena. "A High Resolution Record of the Eemian Interglacial and Transition to the Next Glacial Period from Mount Moulton (West Antarctica)." Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/KorotkikhE2009.pdf.
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Naing, Thann. "Palaeoenvironmental studies of the Middle Triassic uppermost Narrabeen Group, Sydney Basin palaeoecological constraints with particular emphasis on trace fossil assemblages /." Phd thesis, Australia : Macquarie University, 1991. http://hdl.handle.net/1959.14/71228.
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"1990".Thesis (PhD)--Macquarie University, School of Earth Sciences, 1991.
Bibliography: p. 596-630.
PART 1. INTRODUCTION AND METHODOLOGY -- General introduction -- Methodology -- Classification of ichnofacies and lithofacies as used in the present study -- Definition of trace fossil zones (intervals, subintervals and levels) -- General classification of the palaeoenvironments and summary overview of the stratigraphic and geographic distribution of palaeoenvironments in the study area -- PART 2. SYSTEMATIC ICHNOTAXONOMY -- Large dwelling-burrows -- U-shaped burrows -- Vertical cylindrical burrows -- Thalassinoides, Ophiomorpha, Spongeliomorpha and turn-arounds -- Pellets and ovoid-shaped structures -- Bedding-parallel feeding and/or dwelling structures -- Dendritic feeding-burrows -- Rosette-shaped structures -- Escape-structures -- Tracks, trails and resting-traces -- Body fossils and root-penetration structures -- Miscellaneous traces -- PART 3. SYNTHESIS AND CONCLUSIONS -- Trace fossil assemblages (suites) in intervals IC to IF and their distribution in the study area -- Interpretation of the palaeoenvironmental affinities of the trace fossil zones and depositional setting of the study area -- Palaeogeographic synthesis and conclusions.
The coastal exposures of the Triassic System in the Sydney Northshore area aggregate about 180 m in thickness and comprise the uppermost part of the Narrabeen Group (namely, in ascending stratigraphic order: the Bald Hill Claystone, the Garie Formation, and the Newport Formation, the latter divisible into Lower, Middle and Upper Members) and the overlying Hawkesbury Sandstone. With the exception of mainly allochthonous plant macrofossils and palynomorphs which occur sporadically and with varying abundance in the mudrock facies of these formations, environmentally-diagnostic body fossils are rare, and, where they occur, are nowhere unequivocally indicative of marine affinities. For this reasons, and because of the predominantly fluvial lithofacies characteristics exhibited by these formations throughout much of their stratigraphic extent and especially by their channel-form/channel-like sandstones lithosomes, most previous workers have interpreted these formations to be of fluvial or fluvio-lacustrine origin except possibly for several thin planar-and thinly-bedded fine-grained intervals encompassing the Garie and Newport Formations for which several lines of evidence, including lithofacies, equivocal palaeontological, and ichnological evidence, have prompted several workers to speculate a shallow- marine, possibility coastal lagoonal or estuarine origin. -- Although trace fossils occur in reasonable abundance at various stratigraphic levels within these uppermost Narrabeen Group rocks and particularly within the Newport Formation, they have hitherto received very little systematic study. A comprehensive study of this ichnofauna shows that it is relatively diverse, comprising almost 100 different ichnotaxa (including varietal categories) of predominantly invertebrate origin, and includes several new ichnogenera and ichnospecies among the more notable of which are: two large bioglyph-bearing dwelling-burrows of probable crustacean origin (Turimettichnus conaghani and T. webbyi) and one (Pytiniichnus trifurcatum) made either by a small reptile or an amphibian; a multi-stage spiral star-shaped feeding-trace (Helikospirichnus veeversi), probably made by a worm or worm-like deposit-feeder; several new species and varieties of Rhizocorallium (the first record of this ichnogenus in the Triassic of Australia); a new species and new variety of the saltatorial running vertebrate trackway Moodieichnus (an ichnogenus previously known only from the Late Permian of North America); and a new ichnogenus of vertical/steeply-inclined cylindrical branching dwelling-burrow (Barrenjoeichnus mitchelli). -- An alternating stratigraphic pattern of trace fossil abundance and diversity characterizes the upper Narrabeen Group strata in the Sydney Northshore area, and involves four relatively thin separate assemblage zones of relatively diverse ichnofauna and thicker intervening assemblage zones which lack ichnotaxo-nomic diversity. The assemblage zones of diverse trace fossils contain some elements in common to two or more zones, notably: Thalassinoides, Skolithos, Ophiomorpha, Chondrites, Rhizocorallium Palaeophycus, and Planolites, all of which are known to have unequivocal brackish- to shallow-marine palaeoecological affinities and which globally are characteristic of the Skolithos ichnofacies. Additionally, each of these four diverse assemblage zones is characterized by one or more particular index ichnogen-era which for convenience lend their name(s) to the zones as follows, in ascending stratigraphic order: Turimettichnus-Ophio-morpha assemblage zone; Skolithos-Diplocraterion assemblage zone; Helikospirichnus assemblage zone; and Rhizocorallium-Thalass inoides assemblage zone. The intervening ichnotaxonomically less-diverse and relatively impoverished assemblage zones are not similarly and separately named but are characterized by Barrenjoeichnus mitchelli and some species of Palaeophycus, Planolites and Skolithos as well as various plant-root petrification structures, all of which are here argued to have predominantly non-marine palaeoecological affinities. These latter assemblage zones can be referred to the Scoyenia-Teredolites ichnofacies. This stratigraphic pattern of alternating ichnologi-cally diverse and impoverished assemblage zones confirms the suggestions of previous workers (notably Bunny and Herbert, and Retallack) regarding the presence of brackish-/shallow-marine palaeoenvironmental influence in these Lower and Middle Triassic strata and allow for the first time the stratigraphic resolution of the marine strata into four marine tongues which are here named after their respective type localities. These are, in ascending order: The Turimetta Head Tongue (2 m to 3 m thick; extending from at least the middle part of the Bald Hill Clay-stone almost to the top of this formation); the St. Michaels Cave Tongue (4 m to 5 m thick; encompassing the Garie Formation and the lower part of the lower Member of the Newport Formation); the Bangalley Head Tongue (3 m to 5 m thick; extending from the uppermost part of the Lower Member into the lower part of the Middle Member of the Newport Formation); and the Palm Beach Tongue (3 m to 4 m thick; comprising the uppermost part of the Middle Member of the Newport Formation). The trace fossil assemblages in each of these marine tongues are indicative of a complex of brackish- to very shallow-marine low-energy palaeoenvi-ronments typical of modern coastal lagoons or estuaries and imply the presence of a protecting coeval topographic barrier of some kind to the east or southeast. This lagoon is herein called the Newport (Coastal) Lagoon and its development in the central-eastern part of the Sydney Basin coincides approximately with the geographic and depocentral axis of the basin which trends NW-SE and intersects the present coastline in the Sydney metropolitan area. The non-marine affinities of the impoverished and less-diverse trace fossil assemblages in the intervening and overlying strata are consistent with the fluvial/fluvio-lacustrine environmental interpretations of these thicker and predominantly sandstone-dominant intervals made by many other workers. Palaeocur-rent and petrographic data from these fluvial sediments show that the streams in which they formed debouched episodically into the Newport Lagoon variously from the northwest, west and southwest and were sourced variously from both the craton (Lachlan Fold Belt) to the southwest and the New England Orogen to the northeast.
With the exception of evidence of short-lived brackish-marine conditions at the base of the Narrabeen Group in the northeastern Sydney Basin and in the top of the Ashfield Shale in the Wianamatta Group (above the Hawkesbury Sandstone) in the central part of the basin, the Triassic System of the basin is dominated by fluvial/fluvio-lacustrine sediments and the presently described marine tongues of the Newport Lagoon in the uppermost Narrabeen Group are the only other presently known record of marine conditions during the Triassic history of the basin. The development of the Newport Lagoon in the geographic and depocentral axis of the basin attests to the presence of a mild short-lived marine transgression in the latest Early and early Middle Triassic at the end of a period of declining piedmont clastic alluviation from the coeval New England Orogen to the northeast and immediately prior to the onset of a new phase of fluvial sedimentation sourced from the craton to the southwest and manifested by the deposition of the Middle Triassic Hawkesbury Sandstone.
Mode of access: World Wide Web.
xxxv, 630 p. ill., maps
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Chow, Andre M. C. (Andre Mu-Chin). "Sedimentology and paleontology of the Attawapiskat Formation (Silurian) in the type area, northern Ontario." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65494.
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Stritch, Rebecca A. (Rebecca Ann) Carleton University Dissertation Earth Sciences. "Early Cretaceous (Albian) foraminifera in Northwestern and Central Alberta, Canada; biostratigraphy and paleoenvironmental changes." Ottawa, 1997.
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Maldonado, Amy L. "Taxonomy and biostratigraphy of upper Guadalupian radiolaria from the reef trail member of the Bell Canyon formation, Guadalupe Mountains National Park, West Texas, USA /." abstract and full text PDF (UNR users only), 2008. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1459467.
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Thesis (M.S.)--University of Nevada, Reno, 2008."August, 2008." Includes bibliographical references (leaves 142-149). Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2008]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web.
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Kappus, Eric J. "Middle cretaceous dinosaur tracks at Cerro de Cristo Rey, Sunland Park, New Mexico and a comparison with other paleocoastal tracksites of the Southwestern US." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2007. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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O'Brien, Jennifer Ann. "Jurassic biostratigraphy and evolution of the Methow Trough, southwestern British Columbia." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/558073.
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Abke, Rodney Alan. "A fossil assemblage of ostracoda, foraminifera, and gastropoda of the West Texas salt flats." Virtual Press, 1994. http://liblink.bsu.edu/uhtbin/catkey/897497.
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The salt flats of west Texas are large ephemeral lakes, Pleistocene to Holocene in age. The evaporite material in these lakes represents the sedimentary history of the lake and the surrounding area. Recently, a fossil assemblage was found in the sediments of this deposit. This assemblage includes four species of ostracoda (Limnocvthere staplini, Candona rawsoni, Candona thomasi, and Cvprideis salbrosa), two species of gastropoda, (Amnicola decepta, and Amnicola pilsbrvi), and discovery is significant because this assemblage has not been previously reported, and it provides an opportunity to reconstruct part of the physical and chemical environment of the salt flats during a portion of its history. Autecological comparison of these species indicate that they lived in a shallow, alkaline, brackish water environment. The known paleoclimate of the area, and the sedimentology support this interpretation.Department of Geology
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Schmidt, David A. "Paleontology and sedimentology of calcifying microbes in the Silurian of the Ohio-Indiana region an expanded role of carbonate-forming microbial communities /." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1142964356.
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Downing, Kevin Francis. "Biostratigraphy, taphonomy, and paleoecology of vertebrates from the Sucker Creek Formation (Miocene) of southeastern Oregon." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/185976.
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The Sucker Creek Formation exposures at Devils Gate in southeastern Oregon have yielded a significant small mammal fauna of at least thirty small mammal taxa from five stratigraphic horizons. The mammal-bearing portion of the Devils Gate section is more than 200 m thick. Fossil mammals occur in lacustrine and marginal lacustrine deposits lower in the section and occur in overbank and paleosol deposits higher in the section. ⁴⁰Ar/³⁹Ar single-crystal laser-fusion dates on three Devils Gate ashes shows that the age of the mammal-bearing sequence at Devils Gate spans the late early Barstovian land-mammal age with possible overlap into the late Barstovian, as currently defined. Duration of the entire mammal-bearing portion of the Devils Gate section was less than a million years. Both a new ash date from the type section and biostratigraphic correlations between Devils Gate and the type section support considerable temporal overlap between the two exposures. The Devils Gate Local Fauna includes several new taxa: a phyllostomatid bat; two "flying squirrels", Petauristodon sp. A and Petauristodon sp. B; and an eomyid rodent, Leptodontomys sp. A. Several fossil occurrences represent the first record of a taxon in the northern Great Basin and/or in the Barstovian land-mammal age, including: Blackia sp., Schaubeaumys grangeri, Protospermophilus quatalensis, and Pseudadjidaumo stirtoni. The Stagestop locality produced two new taxa, Copemys sp. aff C. esmeraldensis and Mystipterus sp. The Stagestop local fauna is Clarendonian in age. Concretions are an important source of fossil mammals in exposures of the Sucker Creek Formation. Geochemical analyses show that concretions formed through a complex interaction between bone and surrounding volcaniclastic material. Although some superficial bone was consumed during concretion diagenesis, concretion development reduced the chance of prolonged chemical and physical destruction of bone during later soil development. The broad ecological diversity of small mammals recovered from Devils Gate supports an interpretation of the local paleoecology as a mosaic of grassland, forest, and pond/lake-bank environments. Sequential small mammal faunas across a prominent ash event show a generally stable composition with no pronounced ecomorphic differences in pre- and post-volcanic disturbance intervals. Therefore, small mammals do not show analogous ecological patterns to disturbance-driven plant successions in the Sucker Creek Formation. I infer that the local ecosystem recovered from volcanic blasts at a temporal scale below the resolution of time-averaged, post-disturbance paleosols.
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Erasmus, Lelandi. "Virtual reconstruction of stratigraphy and past landscapes in the West Coast Fossil Park region." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1640.
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Rancan, Cristiano Camelo. "Estratigrafia da série eoceno no Baixo do Mosqueiro, bacia de Sergipe-Alagoas /." Rio Claro, 2017. http://hdl.handle.net/11449/151380.
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Orientador: Rosemarie Rohn DaviesCoorientador: Wagner Souza-Lima
Banca: Norberto Morales
Banca: Claudio Borba
Resumo: As rochas do Grupo Piaçabuçu foram alvo de poços exploratórios nos últimos dez anos, nas águas profundas a ultra-profundas da Bacia de Sergipe-Alagoas, que lograram êxito na prospecção de hidrocarbonetos. São também um clássico na história do petróleo no Brasil, pois nelas estão os primeiros campos de produção em águas oceânicas, em reservatórios paleogenos do compartimento estrutural Baixo do Mosqueiro. O estudo estratigráfico da Série Eoceno, com base em perfis elétricos e biozoneamento de poços situados no Baixo do Mosqueiro, exigiu o zoneamento do Grupo Piaçabuçu como um todo, dividido nos intervalos Senoniano, Paleoceno, Eoceno e Oligo-Neogeno. O depocentro senoniano situa-se na Depressão de Areia Branca e os demais na Depressão de Vaza-Barris, deslocados ao longo de cada intervalo, com migração gradual para S e W. A Série Eoceno foi dividida nos intervalos Inferior, Médio e Superior. O primeiro tem depocentro na Depressão de Dourado e os demais na Depressão de Vaza-Barris, condicionados por halocinese e deformação no embasamento. A deposição do Eoceno Inferior ocorreu como uma continuidade do evento de afogamento que se estendia desde o Neopaleoceno (pontuado por deposição progradacional de mar baixo), com superfície de máxima inundação ao nível da biozona N-420. Esta seção possivelmente aflora em superfície na Depressão da Ilha de Mem de Sá. A discordância que define a base do Eoceno Médio (Discordância Pré-luteciana) representa o principal evento erosivo de toda a série e a partir dela os sistemas progradaram no Meso e Neoeoceno, com recuo de depocentro no último. No Mesoeoceno o limite entre o Baixo do Mosqueiro e a Plataforma de Estância foi colmatado pela sedimentação e as sub-bacias de Sergipe e Jacuípe passaram a atuar como um único compartimento estrutural. Na Depressão de Vaza-Barris predominaram ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Piaçabuçu Group rocks were exploratory targets of many wildcats along the last ten years, on deep to ultradeep water of Sergipe-Alagoas Basin, with sucess in petroleum search. This stratigraphic unit is a classic production zone on Brazil's petroleum history, because the first offshore discovery where there, in Paleogene reservoirs of Mosqueiro Low Compartiment. A stratigraphic study in Eoceno Series, based on well logs and biostratigraphic data had the objective of understand depositional systems spacial distribution, response to accomodation space variation, controlled by eustasy and deformational history in time. In order to compreend this, Piaçabuçu Group was zoned in four intervals: Senonian, Paleocene, Eocene and Oligo-Neogen. Senonian Depocenter was in Areia Branca Trough and for the others in Vaza-Barris Trough, but gradually migrated along time to S and W. Eocene Series was shared in tree intervals: Lower, Middle and Upper. Lower Eocene has depocenter on Dourado Trough, while Middle and Upper Eocene are in Vaza-Barris Trough, controlled by halokinesys and basement deformation, respectively. Lower Eocene deposition was a continuity of Upper Palocene drowning interval (puncuated by progradational deposition on lowstand), with maximum flooding surface at N-420 biozone level. This interval probably outcrops at Ilha de Mem de Sá Trough, in western offshore sector. Middle Eocene basal unconformity is the main erosive event of the Series, and from it, depositional systems are strongly progradacional during Middle and Upper Eocene, with backstepping on the last one. During Lutetian and Bartonian, limits between Mosqueiro Low and Vaza-Barris Trough were buried ans Segipe and Jacuípe sub-basins turned to a single structural compartiment. In VazaBarris Trough, gravity sediments flow facies associations were more commom while in eastern troughs and steps, delta ... (Complete abstract electronic access below)
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Crawford, Kevin A. "The Quaternary Stratigraphy of the Northwind Ridge, Arctic Ocean." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1284698703.
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Batiston, Denis Antonio. "Modelo geológico conceitual do paleocânion de Regência, região onshore da Bacia do Espírito Santo, Cretáceo ao Eoceno /." Rio Claro, 2018. http://hdl.handle.net/11449/180232.
Full textAbstract:
Orientador: Rosemarie Rohn DaviesBanca: Norberto Morales
Banca: Maria Gabriela Castillo Vincentelli
Resumo: O paleocânion de Regência é reconhecido em subsuperfície da bacia do Espírito Santo, localizado nas proximidades da foz do Rio Doce (ES), originado no Cretáceo e preenchido até meados do Eoceno. Dados de 31 seções sísmicas, 29 poços e marcadores bioestratigráficos (definidos por nanofósseis calcários) substanciaram a elaboração de modelos geológicos que aprimoram o conhecimento sobre a evolução do paleocânion. Os resultados incluem correlações estratigráficas, interpretações de feições estruturais e das principais superfícies estratigráficas no âmbito das formações Mariricu, São Mateus, Regência e Urucutuca, assim como seções esquemáticas transversais e longitudinais do paleocânion, mapas de contorno estrutural dos topos litoestratigráficos e de contorno morfológico do paleocânion. Estas informações foram integradas em detalhe para discutir sua origem, o preenchimento e os fatores de controle. Desde o início, o paleocânion foi estruturado por falhas no embasamento. Próximo ao topo da Formação Mariricu, de idade aptiana, já há indícios de uma extensa calha rasa. O paleocânion é dividido pela Zona de Charneira Cedro-Rio Doce (ZCCRD), que é um sistema de falhas normais de direção praticamente N-S. A morfologia e a largura do paleocânion também foram controladas por diversas falhas normais menores nos blocos proximal e distal à ZCCRD, originadas no embasamento, ainda ativas quase até o final do preenchimento do paleocânion, com direção principalmente SO-NE. Falhas normais também ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Santo Basin, located near to the mouth of the Doce River (State of Espírito Santo, Southeast Brazil), carved from the Cretaceous and filled up to the mid Eocene. Data of 31 seismic sections, 29 wells and biostratigraphic markers (of calcareous nannofossils) have substantiated the conception of geological models that improve the awareness concerning the paleocanyon evolution. The results include stratigraphic correlations, structural geology interpretations and stratigraphic surfaces determination within the Mariricu, São Mateus, Regência and Urucutuca formations, as well as schematic transversal and longitudinal sections of the paleocanyon, structural contour maps of the lithostratigraphic tops and morphologic contour map of the paleocanyon. These information were integrated in detail to promote discussion about the origin, the filling and the controls of the paleocanyon development. Since the beginning, the structure was related to faults in the basement. The first long shallow channel is evidenced near the top of the Aptian Mariricu Formation. The paleocanyon is divided into a proximal block and a distal one by an almost N-S system of normal faults designated as Cedro-Rio Doce Fault Zone (CRDFZ). In both blocks, the morphology and width of the paleocanyon were also controlled by several smaller normal faults with main SW-NE direction, originated in the basement, still moving until the almost complete fill of the paleocanyon, with main direction SW-NE. Normal faults were als... (Complete abstract click electronic access below)
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BARTHOLOMEW, ALEXANDER. "CORRELATION OF HIGH ORDER CYCLES IN THE MARINE-PARALIC TRANSITION OF THE UPPER MIDDLE DEVONIAN (GIVETIAN) MOSCOW FORMATION, EASTERN NEW YORK STATE." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1022593337.
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Voltani, Cibele Gasparelo. "O acervo paleoictiológico do Aptiano-Albiano da Formação Santana (Bacia do Araripe), existente nas coleções do Museu de Paleontologia e Estratigrafia "Paulo Milton Barbosa Landim", DGA-IGCE UNESP Rio Claro /." Rio Claro : [s.n.], 2011. http://hdl.handle.net/11449/92920.
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Orientador: Reinaldo José BertiniCoorientador: Paulo M. Machado Brito
Banca: Maria Rita Caetano Chang
Banca: Alexandre Magno Feitosa Sales
Resumo: A Bacia do Araripe é a maior estrutura bacinal interior do Nordeste brasileiro, com História Geológica apresentando registros desde a Era Paleozóica. Mas é do Cretáceo que vem sua notabilidade. O Membro Romualdo da Formação Santana é um autêntico lagerstätten, cujos fósseis estão magnificamente preservados e são muito diversos, especialmente entre os vertebrados. Entre estes estão descritos cerca de 30 morfótipos de peixes. Uma parte significativa desta diversidade encontra-se depositada no Museu de Paleontologia e Estratigrafia "Paulo Milton Barbosa Landim", UNESP, Campus de Rio Claro. São 13 gêneros representados, distribuídos em 3.119 espécimens. Parte deste material foi analisado, a fim de trazer contribuições sobre a Osteologia de cada grupo, bem como Paleobiogeografia, Paleoecologia, Cronobioestratigrafia
Abstract: The Araripe Basin is the largest interior basin structure from Northeastern Brazil, which has a Geological History presenting data since the Paleozoic Era. Nevertheless its notability comes from the Cretaceous. The Romualdo Member from the Santana Formation is an authentic largerstätten, containing an excellently preserved diverse fossil assemblage, especially vertebrates. Among those are described about 30 morphotypes of fishes. A meaningful portion of this diversity is found deposited on "Museu de Paleontologia e Estratigrafia "Paulo Milton Barbosa Landim", UNESP, Rio Claro Campus. There are 13 genera represented, distributed on 3.119 specimens. Part of this material has been analised, in order to contribute with the Osteology of each group, as well as to Paleobiogeography, Paleoecology and Chronobiostratigraphy
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Barbour, Susan Leigh. "Microstratigraphic Analysis of an Amalgamated Horizon in the Type Cincinnatian:Implications for Spatio-Temporal Resolution in the Fossil Record." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1030643781.
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Swift, Robert James Anthony. "Conodont Biostratigraphy and δ¹³C Chemostratigraphy of the Salina Group (Silurian) in Western Ohio and Eastern Indiana." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1313675443.
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Voltani, Cibele Gasparelo [UNESP]. "O acervo paleoictiológico do Aptiano-Albiano da Formação Santana (Bacia do Araripe), existente nas coleções do Museu de Paleontologia e Estratigrafia Paulo Milton Barbosa Landim, DGA-IGCE UNESP Rio Claro." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/92920.
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Made available in DSpace on 2014-06-11T19:26:14Z (GMT). No. of bitstreams: 0
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voltani_cg_me_rcla.pdf: 3761766 bytes, checksum: b819d81d58be398c33a3c1bcd92c037f (MD5)A Bacia do Araripe é a maior estrutura bacinal interior do Nordeste brasileiro, com História Geológica apresentando registros desde a Era Paleozóica. Mas é do Cretáceo que vem sua notabilidade. O Membro Romualdo da Formação Santana é um autêntico lagerstätten, cujos fósseis estão magnificamente preservados e são muito diversos, especialmente entre os vertebrados. Entre estes estão descritos cerca de 30 morfótipos de peixes. Uma parte significativa desta diversidade encontra-se depositada no Museu de Paleontologia e Estratigrafia “Paulo Milton Barbosa Landim”, UNESP, Campus de Rio Claro. São 13 gêneros representados, distribuídos em 3.119 espécimens. Parte deste material foi analisado, a fim de trazer contribuições sobre a Osteologia de cada grupo, bem como Paleobiogeografia, Paleoecologia, Cronobioestratigrafia
The Araripe Basin is the largest interior basin structure from Northeastern Brazil, which has a Geological History presenting data since the Paleozoic Era. Nevertheless its notability comes from the Cretaceous. The Romualdo Member from the Santana Formation is an authentic largerstätten, containing an excellently preserved diverse fossil assemblage, especially vertebrates. Among those are described about 30 morphotypes of fishes. A meaningful portion of this diversity is found deposited on “Museu de Paleontologia e Estratigrafia “Paulo Milton Barbosa Landim”, UNESP, Rio Claro Campus. There are 13 genera represented, distributed on 3.119 specimens. Part of this material has been analised, in order to contribute with the Osteology of each group, as well as to Paleobiogeography, Paleoecology and Chronobiostratigraphy
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Huffer, Amanda R. "The Sedimentological and Paleontological Characteristics of the Portersville Shale, Conemaugh Group, Southeast Ohio." Ohio University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1183737592.
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Fanti, Federico <1981>. "Stratigraphy and Palaeontology of the Late Cretaceous Wapiti Formation, west-central Alberta, Canada." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/1498/.
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A complete stratigraphic assessment and revision of the middle Campanian to upper Maastrichtian Wapiti Formation in north-western Alberta and north-eastern British Columbia is the main aim of this research project. The study area encompasses an area of approximately 200X180 km in the Grande Prairie County (west-central Alberta) and easternmost British Columbia, Canada. Results presented here indicate that the 1300m thick succession currently reported in the literature as “undifferentiated lithostratigraphic unit”, consists of five lithostratigraphic units and four unconformity-bounded depositional sequences; their study and description have been documented integrating several geological disciplines, including sequence stratigraphic methods, well-log signatures, facies analysis, and fossil associations. On the whole, particular attention has been given to 1) age and nature of both basal and upper contacts of the Wapiti Formation, 2) effective mappability of lithostratigraphic units and depositional sequences in western Alberta, and 3) the identification of previously undetermined maximum flooding surface of the Bearpaw seaway and Drumheller Marine Tongue, which are reference marine unit in central and southern Alberta. A second, but not less important, guideline for the project has been the rich paleontological record of the Wapiti deposits. Detailed paleoenvironmental and taxonomical information on old and new finds have been the base for correlation with well known associations of Alaska, southern Alberta, and Montana. Newly discovered rich fossil localities documented an extraordinarily diverse fauna during the latest Cretaceous, including dinosaurs, squamates, and fresh-water fishes and reptiles.
Lastly, in order to better characterize the Wapiti Formation, major marker beds were described: these include several bentonites (altered volcanic ash deposits) which have been documented over an area of almost 30.000 km2, as well as four major coal zones, characterized by tabular coal seams with an overall thickness of 2 meters. Such marker beds represent a formidable tool for high-resolution chronology and regional correlations within the Late Cretaceous Alberta foreland basin.
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Beamud, Amorós Elisabet. "Paleomagnetism and Thermochronology in Tertiary systectonic sediments of the South-central Pyrenees: Chronostratography, kinematic and exhumation constraints." Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/129314.
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This PhD Thesis presents the Tertiary kinematic evolution of the South-Central Pyrenees from the integration of magnetostratigraphic, magnetotectonic and thermochronological analyses on its synorogenic sedimentary record.
One of the main contributions of this PhD thesis is the continuous absolute dating of the syntectonic conglomerates of La Pobla de Segur, Senterada and Sis. Magnetostratigraphy of these materials establishes their deposition during Middle Eocene-Late Oligocene times (from chron 19r up to chron 9n). Integration of these results with previous magnetostratigraphic works within the Ainsa Basin has allowed the establishment of a new chronostratigraphy for the Eocene-Oligocene materials of the South-Central Pyrenees.
The obtained chronostratigraphy has biochronological implications as it substantially changes the traditionally accepted ages of the European reference levels MP14 to MP17. MP14 and MP15 reference levels are proposed to correlate to Lutetian whereas MP16 and MP17 would be Bartonian in age. These results reveal that the correlation between the continental and marine Paleogene record needs further refinement and therefore, that the chronostratigraphic age attributions based on MP reference levels should be taken with caution.
The magnetostratigraphic ages have been combined with detrital thermochronology on 13 granitic cobbles enclosed in the syntectonic conglomerates. The detrital apatite fission track ages obtained vary from 63 to 27 Ma. When these ages are combined with the stratigraphic ages, samples define 5 groups with thermochronological ages generally increasing down-section except in the most deeply buried ones due to post-depositional partial annealing. Thermal models reveal three periods of rapid-cooling within the Axial Zone due to movement on large-thrust sheets. A dramatic increase in exhumation rate occurred during the latest Eocene-Early Oligocene related to the onset of movement in the Rialp thrust sheet and the increase in structural relief of the Axial Zone by underthrusting. The magnetostratigraphic and thermochronological ages obtained permit the link between the sedimentation rates in the surrounding basins and the exhumation rates in the hinterland, and reveal that accommodation space exerted the main control on sedimentation rates within the piggy-back basins. Post-depositional annealing of the stratigraphically lowest samples suggests about 2 km of burial by the younger synorogenic materials during progressive burial of the South Pyrenean fold and thrust belt. Thermal models also suggest a rapid exhumation event during the Late Neogene, linked to re-excavation caused by the base level drop during the Ebro River capture to the Mediterranean Sea.
Sedimentation of the studied synorogenic materials during Middle Eocene-Oligocene times occurred coeval to the development of thrust salients in the southern Pyrenees. The magnetotectonic study of 36 sites carried out in the Ainsa Oblique Zone reveal clockwise vertical-axis rotations varying from ~80° in the lower Lutetian materials of the Mediano anticline to ~20° in middle Ilerdian materials cropping out at the northern edge of the Añisclo anticline. Sites in the central part of the Montsec and Bóixols thrust sheets don’t record any significant rotation as neither do the syntectonic materials of La Pobla, Sis and Senterada. The age of the main rotation event within the Gavarnie thrust sheet is constrained to Lutetitan to Bartonian times, when all the structures of the Ainsa Oblique Zone were active. This vertical-axis rotation stage obeys to a difference of ~50 km in the amount of displacement on the Gavarnie thrust sheet controlled by the NE-SW pinch out of the Triassic salts at its basal detachment. A second rotation event of ~ 10° took place since Priabonian times, as a result of the differential displacement of about 22 km of the Serres Marginals thrust sheet, respect the Gavarnie one, on top of the upper Eocene-Oligocene evaporites. The synchronicity between thrusting and vertical-axis rotations suggests that the curved fold and thrust belt formed by progressive curvature with divergent thrust transport.
The results exposed in this Thesis reveal a strong relationship between the stratigraphic record of the synorogenic materials, thrusting and exhumation in the Axial Zone and the structural evolution of the South Pyrenean thrust system. Tectonic forces controlled the observed patterns of exhumation, the evolution of the synorogenic topography of the piggy-back and foreland basins and the depositional features of the synorogenic sediments.Aquesta tesi presenta l’evolució cinemàtica dels Pirineus centre-meridionals durant el Terciari a partir de la integració de dades magnetostratigràfiques, termocronològiques I magnetotectòniques del seu registre sinorogènic. La datació magnetostratigràfica dels conglomerats sintectònics de La Pobla de Segur, Senterada i Sis, fixa la seva edat en Eocè mig-Oligocè superior (cron 19r a cron 9n). Aquests resultats permeten establir una nova cronostratigrafia pels materials eocens-oligocens dels Pirineus centre-meridionals de la que deriven implicacions biocronològiques, ja que canvia substancialment les edats acceptades del nivells de referència europeus MP14 a MP17. Les edats magnetostratigràfiques s’han combinat amb termocronologia detrítica de blocs de granit dels conglomerats sintectònics. La termocronologia obtinguda varia de 63 a 27 Ma. Els models tèrmics revelen tres períodes de refredament ràpid relacionats amb el moviment de grans encavalcaments a la Zona Axial, destacant l’ocorregut a l’Eocè superior-Oligocè inferior degut al moviment de l’encavalcament de Rialp i a l’increment de relleu a la Zona Axial per underthrusting. L’annealing post-deposicional de les mostres estratigràficament més baixes suggereix que el cinturó de plecs i encavalcaments pirinenc va estar cobert per 2 km de materials. Els models tèrmics també suggereixen una exhumació ràpida al Miocè superior, relacionada amb la captura de l’Ebre al Mediterrani. Durant la sedimentació dels materials sinorogènics estudiats té lloc la formació de thrust salients als Pirineus meridionals entre els que destaca la Zona Obliqua d’Ainsa. L’estudi magnetotectònic dut a terme en aquesta zona revela rotacions verticals que varien de ~80º a Mediano a ~20º al nord d’Añisclo. L’edat de la rotació principal a la làmina de Gavarnie s’estableix en el Lutecià-Bartonià, quan eren actives totes les estructures de la Zona Obliqua d’Ainsa, i estaria causada per una diferència de 50 km en la quantitat de desplaçament de la làmina de Gavarnie controlada per la distribució de les sals triàsiques al seu desenganxament basal. La sincronia entre encavacalments i rotacions apunta a un model d’arc progressiu amb transport divergent. Aquests resultats revelen una estreta relació entre el registre estratigràfic dels materials sinorogènics, els encavalcaments i l’exhumació a la Zona Axial i l’evolució estructural del sistema d’envacalments dels Pirineus meridionals. Les forces tectòniques van controlar els patrons d’exhumació, l’evolució de la topografia sinorogènica de les conques intramuntanyoses i d’avantpaís i les característiques deposicionals dels sediments sinorogènics.
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Sanchez, Hernandez Yosmel Mr. "Paleoenvironments and Geochemical Signals from the Late Barremian to the Middle Aptian in a Tethyan Marginal Basin, Northeast Spain: Implications for Carbon Sequestration in Restricted Basins." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1421.
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The hallmark of oceanic anoxic event 1a (OAE1a) (early Aptian ~125 Ma) corresponds to worldwide deposition of black shales with total organic carbon (TOC) content > 2% and a d13C positive excursion up to ~5‰. OAE1a has been related to large igneous province volcanism and dissociation of methane hydrates during the Lower Cretaceous. However, the occurrence of atypical, coeval and diachronous organic-rich deposits associated with OAE1a, which are also characterized by positive spikes of the d13C in epicontinental to restricted marine environments of the Tethys Ocean, indicates localized responses decoupled from complex global forcing factors.
The present research is a high-resolution, multiproxy approach to assess the paleoenvironmental conditions that led to enhanced carbon sequestration from the late Barremian to the middle Aptian in a restricted, Tethyan marginal basin prior to and during OAE1a. I studied the lower 240 m of the El Pui section, Organyà Basin, Spanish Pyrenees. The basin developed as the result of extensional tectonism linked to the opening of the Atlantic Ocean. At the field scale the section consists of a sequence of alternating beds of cm – m-scale, medium-gray to grayish-black limestones and marlstones with TOC up to ~4%.
The results indicate that the lowest 85 m of the section, from latest Barremian –earliest Aptian, characterize a deepening phase of the basin concomitant with sustained riverine flux and intensified primary productivity. These changes induced a shift in the sedimentation pattern and decreased the oxygen levels in the water column through organic matter respiration and limited ventilation of the basin.
The upper 155 m comprising the earliest – late-early Aptian document the occurrence of OAE1a and its associated geochemical signatures (TOC up to 3% and a positive shift in d13C of ~5‰). However, a low enrichment of redox-sensitive trace elements indicates that the basin did not achieve anoxic conditions. The results also suggest that a shallower-phase of the basin, coeval with platform progradation, may have increased ventilation of the basin at the same time that heightened sedimentation rates and additional input of organic matter from terrestrial sources increased the burial and preservation rate of TOC in the sediment.
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Sanjuan, i. Girbau Josep. "Els caròfits del límit Eocè-Oligocè de la Conca de l’Ebre." Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/133718.
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Aquesta tesi doctoral té com a objectiu principal la caracterització taxonòmica, paleoecològica, paleobiogeogràfica i biostratigràfica dels caròfits de l’Eocè superior-Oligocè inferior de la Conca de l’Ebre.
La flora de caròfits de l’Eocè superior-Oligocè inferior del marge est de la Conca de l’Ebre està constituïda per Sphaerochara labellata, Chara aff. antennata, C. artesica n. sp., C. rhenana, C.microcera, Psilochara aff. acuta, Lamprothamnium sp., Gyrogona caelata, Nodosochara jorbae, Lychnothamnus longus, L. stockmansii, L. grambastii, L. vectensis, L. pinguis (=L. major), Nitellopsis (Tectochara) merianii, Harrisichara lineata, H. vasiformis-tuberculata i H. tuberculata. En totes es caracteritza el polimorfisme intraespecífic a parti d’un estudi biomètric dels girogonits. Des d’un punt de vista taxonòmic se sinonimitzen, a partir de les poblacions tipus, dues espècies clau en biostratigrafia del límit Eocè-Oligocè europeu, Lychnothamnus pinguis i L. major.
L’anàlisi paleoecològica de les associacions de caròfits de l’Eocè superior al sector NE de la conca de l’Ebre ha permés determinar que espècies clau per la biostratigrafia del límit Eocè-Oligocè presenten clares limitacions paleoecològiques. Així, Harrisichara vasiformis-tuberculata creixeria només en ambients salabrosos i soms pròxims a la costa, Harrisichara lineata es relaciona amb llacs soms d’aigua dolça i Harrisichara tuberculata abunda, però no és exclusiva, de llacs perennes i profunds d’aigua dolça. Altres espècies com Sphaerochara labellata, Lychnothamnus stockmansii, L. pinguis (=L. major) i Chara microcera es troben en llacs permanents. En conclusió, la presència o absència d’aquestes espècies, i per tant, de les biozones homònimes en una determinada conca europea depèn del tipus de fàcies i del paleoambient associat mes que no d’esdeveniments evolutius. Altres espècies com Lychnothamnus vectensis, Nodosochara jorbae, Lychnothamnus longus o Chara artesica n. sp., en canvi, no presenten cap limitació ecològica important dins el context dels sistemes aquàtics continentals.
L’anàlisi paleobiogeogràfica de la caroflora de l’Eocè superior-Oligocè inferior d’Europa permet identificar una polaritat latitudinal en la distribució i abundància de les espècies. No obstant, partint de les espècies comunes a totes les conques europees es defineix una bioprovíncia europea per l’Eocè superior-Oligocè inferior la qual es pot caracteritzar a partir dels llinatges Harrisichara vasiformis-H. tuberculata i Lychnothamnus stockmansii-L. major així com de les espècies Nitellopsis (T.) merianii i Chara microcera. Les variacions regionals d’aquesta flora responen a factors climàtics locals i a factors ecològics lligats a la dinàmica de cada conca. La distribució biogeogràfica de determinades espècies, com Sphaerochara labellata o L. pinguis ha mostrat que l’us d’aquestes especies en biostratigrafia està condicionada per factors paleogeogràfics. L’anàlisi de la biogeografia històrica del llinatges evolutius Lychnothamnus stockmansii-L. major i Nitellopsis(Tectochara)merianii-N. obtusa suggereix que les espècies de caràcies fòssils seguien diferents patrons de dispersió en funció de la disposició dels seus gametangis (dioica vs. monoica). És clar que les espècies monoiques com Lychnothamnus stockmansii-L. major, amb velocitats d’expansió geològicament instantànies, són idònies alhora de correlacionar biostratigraficament conques allunyades.
Des d’un punt de vista biostratigràfic, les associacions de caròfits han permès precisar l’atribució biostratigràfica de les unitats litostratigràfiques estudiades. S’ha proposat una biozonació de carofits per la conca de l’Ebre a partir d’espècies ecològicament euritípiques. Aquesta biozonació s’ha correlacionat amb la biozonació local de vertebrats i s’ha calibrat amb la magnetostratigrafia definida a l’est de la conca per Barberà et al. (2001) i Costa et al. (2010, 2011). La nova proposta permet caracteritzar el límit Eocè-Oligocè dins la biozona de Lychnothamnus vectensis. A més, s’ha revisat la biozonació europea avui dia en us. La calibració dels límits de les biozones europees amb l’escala del temps absolut mitjançant la magnetostratigrafia ha permès, per primera vegada, precisar la durada temporal de les biozones de caròfits del límit Eocè-Oligocè.
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Ji, Zailiang. "Lower Ordovician conodonts from the St. George Group of Port au Port Peninsula, Western Newfoundland /." 1989. http://collections.mun.ca/u?/theses,107555.
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Jinnah, Zubair Ali. "Tectonic and sedimentary controls, age and correlation of the Upper Cretaceous Wahweap Formation, southern Utah, U.S.A." Thesis, 2012. http://hdl.handle.net/10539/11397.
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Ph.D., Faculty of Science, University of the Witwatersrand, 2011The Wahweap Formation is an ~400 m thick clastic sedimentary succession of fluvial and estuarine channel sandstones and floodbasin mudrocks that was deposited in western North America during the Late Cretaceous. It preserves important mammal, dinosaur, crocodile, turtle and invertebrate fossils that have been the subject of recent palaeontological investigations. The Wahweap Formation can be divided into lower, middle, upper, and capping sandstone members based on sand:mud ratios and degree of sandstone amalgamation. Facies analysis reveals the presence of ten facies associations grouped into channel and floodbasin deposits. Facies associations (FAs) from channels include: (1) single-story and (2) multistory lenticular sandstone bodies, (3) major tabular sandstone bodies, (4) gravel bedforms, (5) low-angle heterolithic cross-strata, and (10) lenticular mudrock, whereas floodbasin facies associations include: (6) minor tabular sandstone bodies, (7) lenticular interlaminated sandstone and mudrock, (8) inclined interbedded sandstone and mudrock, and (9) laterally extensive mudrock. The lower and middle members are dominated by floodbasin facies associations. The lower member consists dominantly of FA 8, interpreted as proximal floodbasin deposits including levees and pond margins, and is capped by a persistent horizon of FA 3, interpreted as amalgamated channel deposits. FAs 4 and 6 are also present in the lower member. The middle member consists dominantly of FA 9, interpreted as distal floodbasin deposits including swamp, oxbow-lake and waterlogged-soil horizons. FAs 1, 2, 5, 6, 7, 8, and 10 are present in the middle member as well, which together are interpreted as evidence of suspended-load channels. The upper member is sandstone-dominated and consists of FAs 1, 2, 3, 5, 7, and 8. FAs 5 and 7, which occur at the base of the upper member, are interpreted as tidally influenced channels and suggest a marine incursion during deposition of the upper member. The capping sandstone is characterized by FAs 3, 4, and 6, and is interpreted to represent a major change in depositional environment, from meandering river systems in the lower three members to a low-accommodation, braided river system. Combined results of facies and palaeosol analyses suggest that the overall climatic conditions in which the Wahweap Formation was deposited were generally wet but seasonally arid, and that iv conditions became increasingly moist from the time of lower member deposition up to the time of middle member deposition. Improved age constraints were obtained for the Wahweap Formation by radiometric dating of two devitrified ash beds (bentonites). This allowed for deposition to be bracketed between approximately 81 Ma and 76 Ma. This age bracket has two important implications: firstly, it shows that the Wahweap Formation is synchronous with fossiliferous deposits of the Judithian North American Land Mammal Age, despite subtle differences in faunal content. Secondly, it shows that the middle and upper members were deposited during the putatively eustatic Claggett transgression (T8 of Kauffman 1977) in the adjacent Western Interior Seaway. This is consistent with facies analysis which shows a marked increase in tidally-influenced sedimentary structures and trace fossils at the top of the middle and base of the upper members. Following recent alluvial sequence stratigraphic models, the middle member is interpreted as the isolated fluvial facies tract, while the upper member represents the tidally influenced and highstand facies tracts. Maximum transgression occurred during deposition of the lowest part of the upper member, synchronous with the Claggett highstand in other parts of the Western Interior Basin. The sequence boundary is placed at the base of the overlying capping sandstone member, diagnosed by a major shift in petrography and paleocurrent direction, as well as up to 4 m of fluvial incision into the underlying upper member. The capping sandstone member is interpreted as the amalgamated fluvial facies tract of an overlying sequence. Analysis of the western-most exposures of the Wahweap Formation on the Markagunt and Paunsaugunt plateaus shows facies variations in the proximal and distal parts of the central Western Interior Basin. The inconsistent thickness and variations in fluvial architecture, as well as the presence of unconformities and generally poor exposure in the west, hinder correlation attempts and also prevent the subdivision of the Wahweap Formation into members. Only the capping sandstone, which can be positively identified west of the Paunsaugunt fault, has a consistent thickness and fluvial architecture across the west-east extent of the Wahweap Formation. The capping sandstone also bears remarkable lithological similarity to the Tarantula Mesa Formation which is exposed to the east in the Henry Mountains Syncline, and it is suggested that these two units be equated under the name “Tarantula Mesa Formation”, which has precedence.
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Watson, Simon Timothy. "Conodonts from a core of the Nita and Goldwyer Formations (Lower Middle Ordovician) of the Canning Basin, Western Australia /." 1986. http://collections.mun.ca/u?/theses,119083.
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Witebsky, Susan. "Paleontology and sedimentology of the Haymond boulder beds (Martin Ranch), Marathon Basin, Trans-Pecos Texas." 1987. http://hdl.handle.net/2152/11931.
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A boulder bed unit in the upper Haymond Formation (Pennsylvanian), generally believed to be olistostromes, is exposed in the eastern Marathon Basin, west Texas. Two localities of this unit (Housetop Mountain and Clark Butte) contain clasts derived from several formations found within the basin, as well as exotic Devonian metamorphic and volcanic rocks. This report describes a third previously unstudied site (Martin Ranch locality) that contains clasts of exotic Middle Cambrian shelf limestones. These limestones provide a key to the Early Paleozoic history of the Marathon region. The boulder beds lie in the upper part of the Haymond Formation. At the Martin Ranch locality they form a zone that is traceable for 6.6 km along strike and is up to 230 m thick. These boulder beds contain interbedded units of massive, unstratified, pebble- to boulder-bearing mudstone, thickly bedded, massive sandstone, lenses of pebbly sandstone, and deformed flysch beds. About 80 percent of the clasts found in the boulder beds at Martin Ranch are chert derived from several basin formations. Unique displaced slabs of bedded chert pebble conglomerate comprise about 10 percent of the clasts. Theses conglomerates were probably derived from upper fan-channel deposits within the lower Haymond Formation. Pennsylvanian limestone clasts redeposited from the basin facies of the Dimple Formation and clasts of exotic, late Middle Cambrian limestones each comprise about 5 percent of the clasts. These Cambrian limestones, older than any formation in the Marathon Basin, contain a fauna characteristic of the seaward edge of the cratonic carbonate shelf. The presence of the Cambrian clasts constrains the location of the North American shelf edge during the Cambrian, placing it at least 120 km southeast of the present day Marathon Basin. Both the Martin Ranch and Housetop Mountain boulder beds are composed mainly of clast-bearing, matrix-supported mudstone which have pebbly sandstone, massive sandstone, and flysch beds interstratified with the mudstone and represent periodic deposition of debris flows, slumps, slides, and turbidites interspersed with normal basin deposition of flysch facies rocks. However, different clast types are found at the two localities. The Martin Ranch locality has clasts of Cambrian limestone and chert pebble conglomerate, the latter up to 90 m in length, that are absent at the other localities. Exotic Pennsylvanian limestone clasts and exotic Devonian metamorphic and volcanic rocks, common at Housetop Mountain, are rare or missing at Martin Ranch. The Clark Butte locality is unique because it lacks the mudstone which dominates the other two localities. Instead, the matrix is composed of a pebbly sandstone and conglomerate associated with thick sandstone beds. The boulder beds at this locality may represent upper fan channels and channel-lag deposits. The turbidites and olistostromes resulted from recycling of the southern edge of the tectonic basin as the advancing Ouachita thrusts uplifted the pre Haymond strata. Most of the clasts were from older basin formations exposed by these faults; however one of these thrusts also uplifted slivers of exotic Middle Cambrian limestone. Earthquakes probably triggered slumps and rock falls off the fault scarps. As the boulders travelled downslope plowing through the slope sediments, they accumulated more material. This combination of slide debris and slope mud turned the slumps and slides into debris flows. Between episodes of debris flows and turbidity currents, normal basin deposition of thinly bedded turbiditic sandstone and pelagic shale occurred.text
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Tsukui, Kaori. "Chronology and Faunal Evolution of the Middle Eocene Bridgerian North American Land Mammal “Age”: Achieving High Precision Geochronology." Thesis, 2015. https://doi.org/10.7916/D8KS6R86.
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The age of the Bridgerian/Uintan boundary has been regarded as one of the most important outstanding problems in North American Land Mammal “Age” (NALMA) biochronology. The Bridger Basin in southwestern Wyoming preserves one of the best stratigraphic records of the faunal boundary as well as the preceding Bridgerian NALMA. In this dissertation, I first developed a chronological framework for the Eocene Bridger Formation including the age of the boundary, based on a combination of magnetostratigraphy and U-Pb ID-TIMS geochronology. Within the temporal framework, I attempted at making a regional correlation of the boundary-bearing strata within the western U.S., and also assessed the body size evolution of three representative taxa from the Bridger Basin within the context of Early Eocene Climatic Optimum. Integrating radioisotopic, magnetostratigraphic and astronomical data from the early to middle Eocene, I reviewed various calibration models for the Geological Time Scale and intercalibration of 40Ar/39Ar data among laboratories and against U-Pb data, toward the community goal of achieving a high precision and well integrated Geological Time Scale.
In Chapter 2, I present a magnetostratigraphy and U-Pb zircon geochronology of the Bridger Formation from the Bridger Basin in southwestern Wyoming. The ~560 meter composite section spans from the lower Bridger B to the Bridger E, including the Bridgerian/Uintan NALMA boundary in the uppermost part of the section. Analysis of samples from 90 sites indicates two paleomagnetic reversals that are correlated to an interval spanning Chrons C22n, C21r, and C21n by comparison to the Geomagnetic Polarity Time Scale (GPTS). This correlation places the Bridgerian/Uintan faunal boundary within Chron C21n, during the initial cooling phase following the peak of the Early Eocene Climatic Optimum. Based on the bio- and magnetostratigraphic correlation, I provide correlation of other Bridgerian/Uintan boundary-bearing sections to the GPTS, demonstrating that in the western North America, the Bridgerian/Uintan boundary occurs everywhere in Chron C21n. In addition, U-Pb zircon geochronological analyses were performed on three ash beds from the Bridger Formation. High-precision U-Pb dates were combined with the paleomagnetic polarity data of the same ash beds as well as the integrative chronostratigraphy of the basin to assess prior calibration models for the Eocene part of the GPTS. The data from the Bridger Formation indicate that the Option 3 age model of Westerhold et al. (2008) best reconciles the geochronological data from all of the ash beds except for one. Thus I favor this Option 3 model, which indicates the ages of 56.33 Ma and 66.08 Ma for the Paleocene-Eocene Thermal Maximum and Cretaceous/Paleogene boundary, respectively.
In Chapter 3, the body size evolution of three mammalian taxa from the Bridgerian NALMA was analyzed within the context of Bergmann’s Rule, which poses a correlation between the size of endotherms and climate (latitude). The Bridgerian NALMA is from a time of global cooling following the peak of the Early Eocene Climatic Optimum, thus according to Bergmann’s Rule, the Bridgerian mammals are expected to increase in size. This hypothesis is tested among Notharctus, Hyopsodus, and Orohippus, using the size of molar dentition as a proxy for their body size. These taxa represent three different ecomorphs, and I investigated if these taxa showed a pattern of body size change consistent with the prediction made by Bergmann’s Rule, and how their ecological adaptation may have affected their response to the climate change. Prior to analyzing the body size evolution, specimens of Notharctus and Hyopsodus were identified to species based on dental characters. This practice differs from previous studies in which species identification relied on relative size of the individuals and stratigraphic levels of origin. Within the new framework of morphologically determined species identification, five species of Notharctus were recognized, among which, N. pugnax, N. robustior and N. sp. indet. exhibited statistically significant body size increase in the time span of interest. Based on morphological analyses of Hyopsodus dentition, I recognized five species. Dentition-based body size analysis showed that H. lepidus and H. despiciens exhibited a statistically significant change towards larger size within the sampled interval. When analyzed at the generic level, a statistically significant increase was observed for both Notharctus and Hyopsodus. Finally, a genus-level analysis of Orohippus showed a lack of statistically significant size increase over the study interval. Thus, among the three taxa from the Bridgerian, Bergmann’s Rule is supported by Notharctus and Hyopsodus, at least at the genus level, but not by Orohippus, although the patterns are more variable at the intraspecific level.
In Chapter 4, 40Ar/39Ar dates were obtained from sanidines from the middle Eocene Henrys Fork tuff and Upper Carboniferous Fire Clay tonstein, with the goal of making highly precise measurements of these two samples, keyed to the Fish Canyon monitor standard. Analytically, both samples were well characterized, as had been shown previously. The irradiation disk was arranged such that there would have been control from the Fish Canyon surrounding each of the unknown pits. However, due to several complications in the lab during the course of the experiment, only the analyses from one run disk (Disk 677) were of the quality needed for the goals of the study. As a result, the Fish Canyon sanidine standards that were irradiated near the center of the irradiation disk had to be discarded, and thus, the neutron fluence could not be mapped out precisely across the entire disk. The 40Ar/39Ar age relative to Fish Canyon sanidines is 47.828 ± 0.205 Ma and 311.937 ± 1.282 Ma for the Henrys Fork tuff and Fire Clay tonstein, respectively (1σ, including error on the age of the monitor). Because the ages were both offset about the same amount, I explored the option of using the U-Pb ID-TIMS ages of the Henrys Fork tuff and Fire Clay tonstein to test the agreement in the chronometers. The Henrys Fork tuff was dated at 48.260 ± 0.107 Ma (1σ, including error on the age of the monitor) using the Fire Clay sanidines and assuming its age is the U-Pb zircon age. The Fire Clay tonstein was dated at 314.593 ± 0.699 Ma (1σ, including error on the age of the monitor), using the Henrys Fork sanidines and assuming its age is the U/Pb zircon age. Although the complications encountered render these data unpublishable, they show great promise as the ages of each sanidine sample, tied to the other ash using the other ash’s U-Pb age, give results that are in close agreement between the two chronometers on the same sample (e.g., 314.593 ± 0.699 Ma vs. 314.554 ± 0.020 Ma at 1σ for sanidine and zircon respectively from the Fire Clay tonstein, and 48.260 ± 0.107 Ma vs. 48.265 ± 0.008 Ma 1σ for sanidine and zircon respectively from the Henrys Fork tuff).
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Wade, Benjamin P. "Unravelling the tectonic framework of the Musgrave Province, Central Australia." 2006. http://hdl.handle.net/2440/57768.
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The importance of the Musgrave Province in continental reconstructions of Proterozoic Australia is only beginning to be appreciated. The Mesoproterozoic Musgrave Province sits in a geographically central location within Australia and is bounded by older and more isotopically evolved regions including the Gawler Craton of South Australia and Arunta Region of the Northern Territory. Understanding the crustal growth and deformation mechanisms involved in the formation of the Musgrave Province, and also the nature of the basement that separates these tectonic elements, allows for greater insight into defining the timing and processes responsible for the amalgamation of Proterozoic Australia. The ca. 1.60-1.54 Ga Musgravian Gneiss preserves geochemical and isotopic signatures related to ongoing arc-magmatism in an active margin between the North Australian and South Australian Cratons (NAC and SAC). Characteristic geochemical patterns of the Musgravian Gneiss include negative anomalies in Nb, Ti, and Y, and are accompanied by steep LREE patterns. Also characteristic of the Musgravian Gneiss is its juvenile Nd isotopic composition (ɛNd1.55 values from -1.2 to +0.9). The juvenile isotopic signature of the Musgravian Gneiss separates it from the bounding comparitively isotopically evolved terranes of the Arunta Region and Gawler Craton. The geochemical and isotopic signatures of these early Mesoproterozoic felsic rocks have similarities with island arc systems involving residual Ti-bearing minerals and garnet. Circa 1.40 Ga metasedimentary rocks of the eastern Musgrave Province also record vital evidence for determining Australia.s location and fit within a global plate reconstruction context during the late Mesoproterozoic. U-Pb detrital zircon and Sm-Nd isotopic data from these metasedimentary rocks suggests a component of derivation from sources outside of the presently exposed Australian crust. Best fit matches come from rocks originating from eastern Laurentia. Detrital zircon ages range from Palaeoproterozoic to late Mesoproterozoic, constraining the maximum depositional age of the metasediments to approximately 1.40 Ga, similar to that of the Belt Supergroup in western Laurentia. The 1.49-1.36 Ga detrital zircons in the Musgrave metasediments are interpreted to have been derived from the voluminous A-type suites of Laurentia, as this time period represents a “magmatic gap” in Australia, with an extreme paucity of sources this age recognized. The metasedimentary rocks exhibit a range of Nd isotopic signatures, with ɛNd(1.4 Ga) values ranging from -5.1 to 0.9, inconsistent with complete derivation from Australian sources, which are more isotopically evolved. The isotopically juvenile ca. 1.60-1.54 Ga Musgravian Gneiss is also an excellent candidate for the source of the abundant ca. 1.6-1.54 Ga detrital zircons within the lower sequences of the Belt Supergroup. If these interpretations are correct, they support a palaeogeographic reconstruction involving proximity of Australia and Laurentia during the pre-Rodinia Mesoproterozoic. This also increases the prospectivity of the eastern Musgrave Province to host a metamorphised equivalent of the massive Pb-Zn-Ag Sullivan deposit. The geochemical and isotopic signatures recorded in mafic-ultramafic rocks can divulge important information regarding the state of the sub continental lithospheric mantle (SCLM). The voluminous cumulate mafic-ultramafic rocks of the ca. 1.08 Ga Giles Complex record geochemical and Nd-Sr isotopic compositions consistent with an enriched parental magma. Traverses across three layered intrusions, the Kalka, Ewarara, and Gosse Pile were geochemically and isotopically analysed. Whole rock samples display variably depleted to enriched LREE patterns when normalised to chondrite ((La/Sm)N = 0.43-4.72). Clinopyroxene separates display similar depleted to enriched LREE patterns ((La/Sm)N = 0.37-7.33) relative to a chondritic source. The cumulate rocks display isotopically evolved signatures (ɛNd ~-1.0 to .5.0 and ɛSr ~19.0 to 85.0). Using simple bulk mixing and AFC equations, the Nd-Sr data of the more radiogenic samples can be modelled by addition of ~10% average Musgrave crust to a primitive picritic source, without need for an enriched mantle signature. Shallow decompressional melting of an asthenospheric plume source beneath thinned Musgravian lithosphere is envisaged as a source for the parental picritic magma. A model involving early crustal contamination within feeder zones is favoured, and consequently explorers looking for Ni-Cu-Co sulphides should concentrate on locating these feeder zones. Few absolute age constraints exist for the timing of the intracratonic Petermann Orogeny of the Musgrave Province. The Petermann Orogeny is responsible for much of the lithospheric architecture we see today within the Musgrave Province, uplifting and exhuming large parts along crustal scale E-W trending fault/shear systems. Isotopic and geochemical analysis of a suite of stratigraphic units within the Neoproterozoic to Cambrian Officer Basin to the immediate south indicate the development of a foreland architecture at ca. 600 Ma. An excursion in ɛNd values towards increasingly less negative values at this time is interpreted as representing a large influx of Musgrave derived sediments. Understanding the nature of the basement separating the SAC from the NAC and WAC is vital in constructing models of the amalgamation of Proterozoic Australia. This region is poorly understood as it is overlain by the thick sedimentary cover of the Officer Basin. However, the Coompana Block is one place where basement is shallow enough to be intersected in drillcore. The previously geochronologically, geochemically, and isotopically uncharacterised granitic gneiss of the Coompana Block represents an important period of within-plate magmatism during a time of relative magmatic quiescence in the Australian Proterozoic. U-Pb LA-ICPMS dating of magmatic zircons provides an age of ca. 1.50 Ga, interpreted as the crystallisation age of the granite protolith. The samples have distinctive A-type chemistry characterised by high contents of Zr, Nb, Y, Ga, LREE with low Mg#, Sr, CaO and HREE. ɛNd values are high with respect to surrounding exposed crust of the Musgrave Province and Gawler Craton, and range from +1.2 to +3.3 at 1.5 Ga. The tectonic environment into which the granite was emplaced is also unclear, however one possibility is emplacement within an extensional environment represented by interlayered basalts and arenaceous sediments of the Coompana Block. Regardless, the granitic gneiss intersected in Mallabie 1 represents magmatic activity during the “Australian magmatic gap” of ca. 1.52-1.35 Ga, and is a possible source for detrital ca. 1.50 zircons found within sedimentary rocks of Tasmania and Antarctica, and metasedimentary rocks of the eastern Musgrave Province.http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1261003
Thesis(PhD)-- University of Adelaide, School of Earth and Environmental Sciences, 2006
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Ryley, C. Christopher. "Multielement taxonomy, biostratigraphy, and paleoecology of late Triassic conodonts from the Mamonia Complex, Southwestern Cyprus /." 1987. http://collections.mun.ca/u?/theses,137289.
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Mocke, Helke Brigitte. "The postcranium of the carnivorous cynodont Chiniquodon from the Middle Triassic of Namibia and the palaeo-environment of the Upper Omingonde Formation." Thesis, 2016. http://hdl.handle.net/10539/19364.
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A Dissertation submitted to the Faculty of Science, University of the Witwatersrand, in fulfilment of the requirements for the Degree of Master of Science
Johannesburg, 2015The Chiniquodontidae is a family of Triassic carnivorous cynodonts well represented in the Middle-Upper Triassic of Argentina and Brazil. Chiniquodontids were more recently discovered in Madagascar and central Namibia, representing the only record of the family outside South America. The Namibian specimen was discovered in the Upper Omingonde Formation and is represented by the skull and a partial skeleton. The new chiniquodontid was identified as Chiniquodon and is diagnosed by the postcranial characteristics identified; a strong bend in the proximal portion of thoracic ribs, reduced curvature of the clavicle, although this may be due to deformation, robustness of the neck of the ilium, differences in the angulation between the edge of the posterior lamina of the ilium and the margin of the neck, and a large ischium, which is more than twice the size of the pubic plate. The postcranial material of the chiniquodontid from Namibia is described and compared with that of South American chiniquodontids. Chiniquodontids lack costal plates on ribs, show a tall and slender scapular blade, a large acromion process positioned well above the scapular neck and absence of disc-like phalanges in the autopodium. The Namibian Chiniquodon provides the first evidence of elements from the pes in chiniquodontids, and one of the few for non-mammaliaform cynodonts. Sedimentological studies confirm that the Upper Omingonde Formation of Namibia represents fluvial deposits of braided and meandering rivers formed in a predominately arid climatic regime during the Middle Triassic.
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Van, den Brandt Marc Johan. "Cranial morphology of embrithosaurus schwarzi (Parareptilia, Pareiasauria) and a taxonomic and stratigraphic reassessment of the South African Middle Permian Pareiasaurs." Thesis, 2017. http://hdl.handle.net/10539/22742.
Full textAbstract:
A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the Degree of Master of Science.
Johannesburg, 2016.Pareiasaurs were abundant, large, herbivorous parareptiles of the middle and late Permian which had a global distribution. The most basal pareiasaurs are found only in the middle Permian of South Africa, suggesting a Gondwanan origin for the group. Despite their relative abundance, most pareiasaurs are poorly known, especially the large middle Permian South African taxa that went extinct at the end of the Tapinocephalus Assemblage Zone. Historic taxonomic confusion was reduced with studies by Lee (1995, 1997a) that addressed the alpha-taxonomy of all pareiasaurs. He reduced the middle Permian South African pareiasaurs from 11 to four species: Bradysaurus baini, B. seeleyi, Embrithosaurus schwarzi and Nochelesaurus alexanderi. However this revision did not include detailed anatomical descriptions of any of the middle Permian South African Tapinocephalus Assemblage Zone taxa. The first detailed cranial description of Embrithosaurus schwarzi is presented in this contribution. Within the middle Permian pareiasaurians, Embrithosaurus has unique wide, short and stubby teeth with nine marginal cusps arranged more regularly. A cranial taxonomic reassessment of all middle Permian pareiasaurs has confirmed the validity of the four taxa identified by Lee and produced updated cranial diagnoses for each species. Diagnostic features noted by Lee and retained include an autapomorphic large distinctive maxillary boss on a strongly buckled or bent maxilla for B. baini, distinctive horizontally flat and pointed bosses on the posterior margin of the quadratojugal for Nochelesaurus and the smallest cheek flanges for B. seeleyi. Using the updated diagnoses, re-identification of 39 specimens out of 108 studied has produced updated biostratigraphic ranges for the middle Permian species. B. seeleyi is the first to make an appearance, in the middle Koornplaats Member of the Abrahamskraal Formation. B. baini first appears in the upper iii Koornplaats Member, Nochelesaurus in the Swaerskraal Member, and Embrithosaurus in the lower Moordenaars Member of the Abrahamskraal Formation. All taxa disappear by the top of the Karelskraal Member of the Abrahamskraal Formation, confirming that all the middle Permian pareiasaur species went extinct at the end of the Tapinocephalus Assemblage Zone.
MT2017
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Jirah, Sifelani. "Stratigraphy and sedimentology of the middle Permian Abrahamskraal formation (Tapinocephalus Assemblage Zone) in the southern Karoo around Merweville, South Africa." Thesis, 2014.
Find full textAbstract:
A study of the Abrahamskraal Formation in the area around Merweville, in the southwestern corner of the Karoo Basin has revealed the presence of traceable lithological units with lateral continuity throughout the study area. The stratigraphic section measured in this part of the basin matches the section measured by Jordaan, (1990) south of Leeu Gamka, with a basal arenaceous unit overlain by a predominantly argillaceous succession. The thickness of the Abrahamskraal Formation in this part of the Karoo Basin in 2565m, charactersized by a braided depositional environment in the lower 2075m and a meandering depositional environment in the upper 490m. Biostratigraphically the succession comprises a basal Eodicynodon Assemblage Zone which constitutes the lower 1104m and this is overlain by a 1461m thick Tapinocephalus Assemblage Zone whose upper limit is 21m below the Poortjie Member of the Teekloof Formation. This study has also corroborated the work by earlier authors who proposed a northeasterly palaeoflow direction as well as contributing to the global correlation of the Middle Permian terrestrial tetrapod faunas where the Eodicynodon Assemblage Zone correlates with the fauna from the Russian Ocher & Ischeevo; fauna of China’s Xidagou Formation and Rio da Rosto fauna of Brazil while the Tapinocephalus Assemblage Zone fauna corrletaes with fauna from Mezen and Ischeevo in Russia, Posto Queimado fauna in Brazil and those from the Madumabisa strata of Zimbabwe.
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Schmidt, Rolf 1972. "Eocene bryozoa of the St Vincent Basin, South Australia - taxonomy, biogeography and palaeoenvironments." 2003. http://web4.library.adelaide.edu.au/theses/09PH/09phs3491.pdf.
Full textAbstract:
Includes Publication list by the author as appendix A. "July 2003." Includes bibliographical references (leaves 308-324) A stratigraphically detailed taxonomic study of fossil bryozoans within the Late Eocene sediments of the St Vincent Basin, South Australia. These taxa are compared with existing knowledge of fossil and recent faunas in Australia and other regions to enhance understanding of bryozoan evolution and dispersal. Bryozoan taxa and growth forms are used to interpret the palaeoenvironments of the Eocene Vincent Basin.
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Di, Croce Juan. "Eastern Venezuela Basin: Sequence stratigraphy and structural evolution." Thesis, 1996. http://hdl.handle.net/1911/19111.
Full textAbstract:
A regional study has been carried out within the Eastern Venezuela Basin and its offshore continuation to the Orinoco Delta and the Barbados Accretionary Complex. The Eastern Venezuela Basin and its offshore continuation is a Neogene foredeep superimposed on a Mesozoic passive margin.
The Cretaceous to Paleocene of Eastern Venezuela is best subdivided into five second order transgressive-regressive cycles bounded by a 131 Ma (basal Cretaceous) sequence boundary, four maximum flooding surfaces with the inferred age of lower Aptian (111 Ma), upper Albian (98 Ma), middle Cenomanian (95 Ma), middle Turonian (91.5 Ma) and an upper Paleocene sequence boundary (58.5 Ma).
An upper Paleocene to Eocene second-order cycle (58.5 Ma-36 Ma) is followed by the Oligocene which is subdivided into two third-order cycles bounded respectively by 36 Ma, 30 Ma and 25.5 Ma sequence boundaries.
An uppermost Oligocene to lower Miocene (25.5 Ma) basal foredeep unconformity is associated with the sudden deepening of the passive margin in response to the emplacement of the Serrania del Interior.
The Neogene of the Eastern Venezuela foredeep consists of three second-order sequences defined by 25.5 Ma, 16.5 Ma and 10.5 Ma boundaries. In the offshore an upper Miocene (5.5 Ma) unconformity is associated with deeply incised submarine canyons. Sixteen third-order sequence boundaries are recognized and correlated over the region.
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Marty, Richard Charles. "Stratigraphy and chemical sedimentology of Cenozoic biogenic sediments from the Pisco and Sechura Basins, Peru." Thesis, 1989. http://hdl.handle.net/1911/16267.
Full textAbstract:
Neogene sediments rich in siliceous microfossils, phosphate, and organic carbon formed simultaneously in many basins around the Pacific. This work focuses on these (and similar older) sediments from two basins of western South America (East Pisco and Sechura Basins) and studies the effects of tectonism, climate, and oceanic circulation on their formation.
Transgressions inundated the East Pisco Basin during the late Eocene, late early Miocene, and late Miocene. Diatomaceous sediments formed during each transgression. Late Eocene diatomaceous sediments suggest that: upwelling off Peru dates from the late Eocene, a proto-Humboldt current existed during the Eocene, Antarctic cooling began before the latest Eocene, and the terminal Eocene event was the culmination of oceanic-climatic change.
The late Eocene diatomites differ from overlying late Miocene sediments. Eocene diatomites are restricted to the western (offshore) margin of the basin, are separated from paralic sediments by a mud blanket, and were deposited well below wave base. Upper Miocene-Pliocene diatomites occur throughout the basin, grade into paralic deposits, and were deposited, in part, above storm wave base.
The Sechura Basin experienced four transgressions between the Eocene and late Miocene. These transgressions formed four sedimentary sequences. Diatomaceous sediments are found in each sequence except the second (upper Oligocene-lower Miocene). In the third sequence (lower Zapallal Formation) diatomite-phosphorite became important between 14 and 8.1 Ma, and apparently reflects increased biogenic and decreased (?) terrigenous sedimentation rates. The increased biogenic accumulation rate reflects increased primary productivity or preservation. Sediments of the third sequence are separated from the fourth sequence by an angular unconformity (which correlates with subduction of the Nazca Ridge under the basin). Sediments of the fourth sequence differ from those of the third, and apparently record cooling and strengthened currents during the latest Miocene.