Academic literature on the topic 'Geology, Stratigraphic Geology Geology Sedimentation and deposition'
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Journal articles on the topic "Geology, Stratigraphic Geology Geology Sedimentation and deposition"
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Gannaway Dalton, C. Evelyn, Katherine A. Giles, Mark G. Rowan, Richard P. Langford, Thomas E. Hearon, and J. Carl Fiduk. "Sedimentologic, stratigraphic, and structural evolution of minibasins and a megaflap formed during passive salt diapirism: The Neoproterozoic Witchelina diapir, Willouran Ranges, South Australia." Journal of Sedimentary Research 90, no. 2 (February 20, 2020): 165–99. http://dx.doi.org/10.2110/jsr.2020.9.
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ABSTRACT This study documents the growth of a megaflap along the flank of a passive salt diapir as a result of the long-lived interaction between sedimentation and halokinetic deformation. Megaflaps are nearly vertical to overturned, deep minibasin stratal panels that extend multiple kilometers up steep flanks of salt diapirs or equivalent welds. Recent interest has been sparked by well penetrations of unidentified megaflaps that typically result in economic failure, but their formation is also fundamental to understanding the early history of salt basins. This study represents one of the first systematic characterizations of an exposed megaflap with regards to sub-seismic sedimentologic, stratigraphic, and structural details. The Witchelina diapir is an exposed Neoproterozoic primary passive salt diapir in the eastern Willouran Ranges of South Australia. Flanking minibasin strata of the Top Mount Sandstone, Willawalpa Formation, and Witchelina Quartzite, exposed as an oblique cross section, record the early history of passive diapirism in the Willouran Trough, including a halokinetically drape-folded megaflap. Witchelina diapir offers a unique opportunity to investigate sedimentologic responses to the initiation and evolution of passive salt movement. Using field mapping, stratigraphic sections, petrographic analyses, correlation diagrams, and a quantitative restoration, we document depositional facies, thickness trends, and stratal geometries to interpret depositional environments, sequence stratigraphy, and halokinetic evolution of the Witchelina diapir and flanking minibasins. Top Mount, Willawalpa, and Witchelina strata were deposited in barrier-bar-complex to tidal-flat environments, but temporal and spatial variations in sedimentation and stratigraphic patterns were strongly influenced from the earliest stages by the passively rising Witchelina diapir on both regional (basinwide) and local minibasin scales. The salt-margin geometry was depositionally modified by an early erosional sequence boundary that exposed the Witchelina diapir and formed a salt shoulder, above which strata that eventually became the megaflap were subsequently deposited. This shift in the diapir margin and progressive migration of the depocenter began halokinetic rotation of flanking minibasin strata into a megaflap geometry, documenting a new concept in the understanding of deposition and deformation during passive diapirism in salt basins.
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Corfu, Fernando, and Shoufa Lin. "Geology and U-Pb geochronology of the Island Lake greenstone belt, northwestern Superior Province, Manitoba." Canadian Journal of Earth Sciences 37, no. 9 (September 1, 2000): 1275–86. http://dx.doi.org/10.1139/e00-043.
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Mapping and U-Pb geochronology have been used to examine the tectonic and depositional history of the Archean Island Lake greenstone belt in the northwestern Superior Province. The Island Lake greenstone belt comprises two main supracrustal successions, the older Hayes River Group and the younger Island Lake Group. Zircon data for two volcanic units from the Hayes River Group provide identical ages of 2852 ± 1.5 Ma, whereas a turbidite of this group contains a detrital zircon population with ages between 2858 and 2847 Ma. Younger intrusive events include the emplacement of tonalite in the southern batholith at 2825 ± 2 Ma and the Whiteway Island gabbro at 2807 ± 1 Ma. A wacke at the base of the Island Lake Group is dominated by detrital zircon grains yielding ages between 2830 and 2821 Ma, the latter defining a maximum age of sedimentation. A relatively early time of deposition of the lower stratigraphic sections of the Island Lake Group is also supported by an age of 2744 ± 2 Ma obtained for a crosscutting tonalite. By contrast, two turbidite horizons from higher stratigraphic levels of the Island Lake Group contain detrital zircon populations with ages mostly younger than 2730 Ma, the youngest zircon grains providing maximum ages of sedimentation at 2722 and 2712 Ma, respectively. Our results confirm the protracted evolution of the greenstone belt and show in particular that major sedimentary processes were active throughout the main stages of volcanism of the belt. This pattern of protracted sedimentation is comparable to that observed in other greenstone belts of the northwestern Superior Province, all of which developed on pre-Kenoran crust.
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Mel’nikov, N. V. "The Vendian–Cambrian Cyclometric Stratigraphic Scale for the Southern and Central Siberian Platform." Russian Geology and Geophysics 62, no. 08 (August 1, 2021): 904–13. http://dx.doi.org/10.2113/rgg20214339.
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Abstract —The general Vendian stratigraphic scale of Siberia, with the uncertain age of the Vendian base ranging from 600 to 630– 640 Ma in most of recent publications, remains worse constrained than the Cambrian scale, in which the boundaries of epochs and stages have been well defined. However, the imperfect classical stratigraphic division has been compensated by data on the cyclicity of the Vendian–Cambrian sedimentary section. The Vendian stratigraphy of the Siberian Platform and the related deposition history with cycles of sedimentation and gaps, as well as the hierarchy of sedimentation processes, can be inferred from the succession of alternating clastic, carbonate, and salt units. The cyclicity of geologic processes and their recurrence are attributed to periodic oscillatory motions of the crust. The ranks of these motions correlate with the cyclicity of sedimentary strata, including regocyclites, nexocyclites, and halcyclites separated by gaps. Each Vendian long-period oscillatory motion begins with a regocyclite and ends with a regional-scale gap. The Cambrian section includes one pre-Mayan regional gap at the end of the early Cambrian long-period cycle. Cambrian regocyclites are composed of carbonate subformations and formations in the lower part and alternating salt and carbonate beds in the upper part.
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Gong, Chenglin, Dongwei Li, Kun Qi, and Hongxiang Xu. "Flow processes and sedimentation in a straight submarine channel on the Qiongdongnan margin, northwestern South China Sea." Journal of Sedimentary Research 90, no. 10 (October 1, 2020): 1372–88. http://dx.doi.org/10.2110/jsr.2020.68.
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ABSTRACT Straight channels are ubiquitous in deep-water settings, yet flow dynamics and sedimentation in them are far from being well understood. Stratigraphy and flow dynamics of a middle to late Miocene straight channel in Qiongdongnan Basin were quantified, in terms of angle of channel-complex-growth trajectories (Tc), stratigraphic mobility number (M), Froude number (Fr), layer-averaged flow velocity (U), flow thickness (h), and water entrainment coefficient (Ew). The documented channels are composed of three channel complexes (CC1 to CC3) all of which are all characterized by symmetrical channel cross sections without levees and by organized vertical channel-stacking patterns (represented by high mean value of Tc = 37.4° and low mean value of M = 0.038). Turbidity currents in them were estimated to have U of 1.6 to 2.0 m/s (averaging 1.8 m/s), h of 63 to 89 m (averaging 78), Fr of 0.849 to 0.999 (averaging 0.912), and Ew of 0.0003 to 0.0005. They were, in most case, subcritical over most of the channel length, and had a low degree of water entrainment and low flow height scaled to the channel depth (i.e., 0.786 to 0.81 of the channel depth), most likely inhibiting the gradual loss of sediment to form levees. With reference to modeling results of secondary flow velocity vectors of numerical straight channels with the same sinuosity, two parallel gullies seen on both sides of the interpreted channel beds are interpreted to be induced by high-velocity downward backflows produced by the negative buoyancy. Such symmetrical secondary flow structures most likely promoted symmetrical intrachannel deposition (i.e., less deposition along both channel margins but more deposition near the channel center), and thus forced individual channel complexes to progressively aggrade in a synchronous manner, forming straight-channel complexes with symmetrical channel cross sections and organized vertical channel-stacking patterns.
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Walley, C. D. "Depositional history of southern Tunisia and northwestern Libya in Mid and Late Jurassic time." Geological Magazine 122, no. 3 (May 1985): 233–47. http://dx.doi.org/10.1017/s0016756800031447.
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AbstractThe good exposures of virtually undeformed Callovian and Oxfordian strata along the Djeffara escarpment of southern Tunisia and northwestern Libya have allowed analysis of regional depositional history during this time.A number of lithostratigraphic problems are considered. In Tunisia, the Foum Tatahouine Formation is subdivided into members and in Libya some of the stratigraphic issues are clarified. A correlation between the two sequences is proposed. The widely claimed aeolian origin for the Libyan Chameau Mort Sandstone is rejected.The depositional patterns of the Callovian and Oxfordian strata are described in the context of Mid and Late Jurassic sedimentation in the eastern Ghadames basin of the African craton. After a regressive Bathonian sequence, transgressive conditions commenced in Early Callovian time. In a series of continental–marine cycles, this transgressive sequence culminated in widespread shallow, restricted-marine micritic deposition. A regression in Late Callovian time resulted in emergence marked by a thin but widespread calcrete horizon. In Mid? Oxfordian time a renewed transgression brought in open marine, high-energy, shallow-water carbonates. Later, regressive conditions returned, leading to increasing restriction, and latest Jurassic time saw the first signs of the fluvio-deltaic deposition that was to dominate the region in Early Cretaceous time.
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Strogen, Dominic P., Karen E. Higgs, Angela G. Griffin, and Hugh E. G. Morgans. "Late Eocene – Early Miocene facies and stratigraphic development, Taranaki Basin, New Zealand: the transition to plate boundary tectonics during regional transgression." Geological Magazine 156, no. 10 (March 11, 2019): 1751–70. http://dx.doi.org/10.1017/s0016756818000997.
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AbstractEight latest Eocene to earliest Miocene stratigraphic surfaces have been identified in petroleum well data from the Taranaki Basin, New Zealand. These surfaces define seven regional sedimentary packages, of variable thickness and lithofacies, forming a mixed siliciclastic–carbonate system. The evolving tectonic setting, particularly the initial development of the Australian–Pacific convergent margin, controlled geographic, stratigraphic and facies variability. This tectonic signal overprinted a regional transgressive trend that culminated in latest Oligocene times. The earliest influence of active compressional tectonics is reflected in the preservation of latest Eocene – Early Oligocene deepwater sediments in the northern Taranaki Basin. Thickness patterns for all mid Oligocene units onwards show a shift in sedimentation to the eastern Taranaki Basin, controlled by reverse movement on the Taranaki Fault System. This resulted in the deposition of a thick sedimentary wedge, initially of coarse clastic sediments, later carbonate dominated, in the foredeep close to the fault. In contrast, Oligocene active normal faulting in a small sub-basin in the south may represent the most northerly evidence for rifting in southern Zealandia, related to Emerald Basin formation. The Early Miocene period saw a return to clastic-dominated deposition, the onset of regional regression and the southward propagation of compressional tectonics.
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Mitchell, Ross N., Uwe Kirscher, Marcus Kunzmann, Yebo Liu, and Grant M. Cox. "Gulf of Nuna: Astrochronologic correlation of a Mesoproterozoic oceanic euxinic event." Geology 49, no. 1 (August 25, 2020): 25–29. http://dx.doi.org/10.1130/g47587.1.
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Abstract The ca. 1.4 Ga Velkerri and Xiamaling Formations, in Australia and the north China craton, respectively, are both carbonaceous shale deposits that record a prominent euxinic interval and were intruded by ca. 1.3 Ga dolerite sills. These similarities raise the possibility that these two units correlate, which would suggest the occurrence of widespread euxinia, organic carbon burial, and source rock deposition. Paleomagnetic data are consistent with Australia and the north China craton being neighbors in the supercontinent Nuna and thus permit deposition in a single large basin, and the putative stratigraphic correlation. However, lack of geochronological data has precluded definitive testing. The Xiamaling Formation has been shown to exhibit depositional control by orbital cycles. Here, we tested the putative correlation with the Velkerri Formation by cyclostratigraphic analysis. The Velkerri Formation exhibits sedimentological cycles that can be interpreted to represent the entire hierarchy of orbital cycles, according to a sedimentation rate that is consistent with Re-Os ages. Comparison of the inferred durations of the euxinic intervals preserved in both the Xiamaling and Velkerri Formations reveals a nearly identical ∼10-m.y.-long oceanic euxinic event. This permits the interpretation that the two hydrocarbon-rich units were deposited and matured in the same basin of Nuna, similar to the Gulf of Mexico during the breakup of Pangea.
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de Wet, Carol B., Andrew P. de Wet, Linda Godfrey, Elizabeth Driscoll, Samuel Patzkowsky, Chi Xu, Sophia Gigliotti, and Melina Feitl. "Pliocene short-term climate changes preserved in continental shallow lacustrine-palustrine carbonates: Western Opache Formation, Atacama Desert, Chile." GSA Bulletin 132, no. 9-10 (December 23, 2019): 1795–816. http://dx.doi.org/10.1130/b35227.1.
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Abstract Multiple climate proxies indicate episodic changes in moisture levels within an ∼1 Ma duration (early–mid Pliocene) interval. Limestones within the Opache Formation, Calama Basin, Atacama Desert region, Chile, contain evidence for wetter and drier periods on short time scales. Proxies include carbonate lithological changes, paleontology (stromatolites, oncolites, gastropods, ostracods and diatoms), O and C stable isotopes, geochemistry, and mineralogical changes (aragonite, calcite, Mg-calcite, dolomite and gypsum) throughout a 30 m stratigraphic section. Stromatolite fossil cyanobacteria dark and light laminations and mesohaline to hypersaline diatom species suggest Pliocene annual seasonality. Short-term changes between wetter and drier conditions indicate that at least this part of the Atacama region was experiencing relatively rapid early–mid Pliocene climate instability. The predominance of limestone in the Opache Formation, in contrast to the 1500 m of Oligocene-Miocene siliciclastic conglomerates and sandstones, interpreted as arid climate alluvium, that underlie it, indicates a shift from arid or hyperarid climate to a semi-arid climate. Semi-arid conditions promoted limestone deposition in a shallow lacustrine-palustrine environment. In this setting, events such as storms with associated surface water flow, erosion, siliciclastic sand, gravel, and intraclast deposition, coupled with significant biological activity, represent sedimentation during more humid periods in a shallow lacustrine depositional environment. In contrast, limestone characterized by mudcracks, Navicula diatoms, and vadose syndepositional cementation, reflect periods of enhanced evaporation, water shallowing, and episodic desiccation, characteristic of a palustrine depositional system. These facies shifts, in conjunction with geochemical and isotopic proxy evidence, yield a sedimentary record of wetter and drier climate shifts.
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John-Joe, Traynor. "Arenig sedimentation and basin tectonics in the Harlech Dome area (Dolgellau Basin), North Wales." Geological Magazine 127, no. 1 (January 1990): 13–30. http://dx.doi.org/10.1017/s0016756800014138.
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AbstractArenig (Ordovician) clastic sediments crop out in the Harlech Dome region (North Wales), and are placed in a single stratigraphic unit: the Allt Lwyd Formation. This unit records a marine transgression onto an erosion surface produced during late Tremadoc arc volcanicity. Four discrete petrofacies are denned, and reflect differing proportions of detritus derived from Tremadoc-type basic-intermediate igneous rocks, and the local sedimentary basement. Initial shallow marine siliciclastic sandstones and conglomerates are overlain by extensive deep water mud-rich units. These generally shallow up into a complex arc-apron deposit, with sediments derived from the eroding Tremadoc arc, as well as from similar, synchronous volcanics. Predominantly epiclastic sandstones and conglomerates were deposited in deltaic and tidal environments in an arc-apron complex, and capped by condensed mudstones and an ironstone, deposited as sea level rose across these systems. Sediments were ponded in north–south orientated troughs and derived from uplifted blocks. Facies and petrofacies distribution were controlled by syn-sedimentary north-south and northeast–southwest faults. The Allt Lwyd Formation was ponded in a fault-controlled basin (the Dolgellau Basin), one of a series of interconnected sub-basins flooded by the Arenig transgression. The sediments preserved reflect deposition during the transgression of a volcanic arc, prior to the extrusion of marginal basin-type volcanics.
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Rigueti, Ariely L., Patrick Führ Dal' Bó, Leonardo Borghi, and Marcelo Mendes. "Bioclastic accumulation in a lake rift basin: The Early Cretaceous coquinas of the Sergipe–Alagoas Basin, Brazil." Journal of Sedimentary Research 90, no. 2 (February 27, 2020): 228–49. http://dx.doi.org/10.2110/jsr.2020.11.
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ABSTRACT Coquinas constitute widespread deposits in lacustrine, estuarine, and shallow marine settings, where they are a valuable source of information on environmental conditions. Thick coquina successions were deposited in a series of lacustrine rift basins that formed along the Brazilian Continental Margin during the early stages of the opening of the South Atlantic Ocean, in the Early Cretaceous. In the Sergipe–Alagoas Basin, the coquina sequence, equivalent to the Morro do Chaves Formation, crops out in the Atol Quarry, and is considered a relevant analog for the economically important hydrocarbon reservoirs in the Pre-salt strata (Barremian to Aptian) of the Campos Basin (Pampo, Badejo, and Linguado oil fields), which occur only in the subsurface. The aim of this study is to generate a depositional and stratigraphic model through facies and stratigraphic analyses of a well core. These analyses allowed the geological characterization of the Morro do Chaves Formation and of its transition to the adjacent stratigraphic units, the Coqueiro Seco Formation above and the Penedo Formation below, contributing to the growing knowledge of sedimentation in rift basins and exploratory models in hydrocarbon-producing reservoirs. Facies analysis consists of sedimentological, taphonomic, and stratigraphic features of the rocks. Fourteen depositional facies were recognized, stacked into low-frequency and high-frequency, deepening-upward and shallowing-upward cycles driven by the interaction between climate and tectonism. A depositional model is presented, based on the correlation between well-core and outcrop data described in previous studies, providing insights into the spatial distribution of facies. The detailed analysis of facies and stacking patterns sheds light on depositional processes, paleoenvironmental conditions, and the evolution of the system through time, so we may better understand analogous deposits in the geological record.
Dissertations / Theses on the topic "Geology, Stratigraphic Geology Geology Sedimentation and deposition"
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Liu, Qunling. "Post mid-Cretaceous sequence stratigraphy and depositional history of northeastern Gulf of Mexico /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
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Stukins, Stephen. "Spatial and temporal palynological trends in marginal marine depositional system : Lajas Formation, Neuquén Basin, Argentina." Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=167073.
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In order to better understand the relationship of tidally dominated depositional environments and their palynological assemblages, the Middle Jurassic sediments of the Lajas Formation, Neuquén Basin were examined. The ambition was to present models and trends which can be used for studies of other such deposits. In order to integrate the palynoassemblages with the environment of deposition, additional granulometric data and nutrient data from XRF analysis were used in combination with the palynology. A new method using correspondence analysis was used for understanding the palaeoecology and floral dynamics. An updated, dynamic model for the Middle Jurassic floral palaeoecology of the Neuquén Basin has been presented and the drivers of floral succession are interpreted as disturbance tolerance and substrate water content. Taphonomic expressions of seral groupings show that later seral stage community palynomorphs are preferentially deposited within or close to distributary systems, whereas earlier seral stage palynomorphs are preferentially deposited in environments of greater accommodation space, such as bayfills. Taphonomic signatures, using palaeoecological groupings provide trends in low (4th/5th) order cycles and lateral variations relating to tidal channels and surrounding bayfill mudstones. A model for 4th/5th order boundaries is also presented using new interpretations of the distribution of pinaceous pollen and microforaminiferal test linings. Using Canonical Correspondence Ananlysis (CCA), a model is presented of depositional environments incorporating palynological data and granulometric proxies for grain size and grain sorting. The relationship between sediment processes in a tidal flat dominated palaeoenvironment and the hydrodynamic properties of some palynomorphs is investigated and presented. The weathering and nutrient status of the substrates throughout the Lajas Formation is presented using XRF proxy data. The proxies are also used with CCA to create nutrient related floral groupings. When plotted stratigraphically, these show cycles of eutrophication and subsequent weathering of the substrates.
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Hamlin, Herbert Scott. "Syn-orogenic slope and basin depositional systems, Ozona sandstone, Val Verde Basin, southwest Texas /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Smith, Jason J. "A reinterpretation of the sedimentology and stratigraphy of the upper Silurian-lower Devonian Manlius Formation in upstate New York." Diss., Online access via UMI:, 2009.
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Sinclair, Hugh D. "The North Helvetic Flysch of eastern Switzerland : Foreland Basin architecture and modelling." Thesis, University of Oxford, 1989. http://ora.ox.ac.uk/objects/uuid:0e83a6d2-cf51-4dd3-b4bb-523a1d28fc90.
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The North Alpine Foreland Basin (NAFB) comprises sediments of late Eocene to middle Miocene age. The earliest deposits are the North Helvetic Flysch which are exposed in the regions of Glarus and Graubunden, eastern Switzerland. The Taveyannaz sandstones are the first thrust wedge (southerly) derived sediments of the North Helvetic Flysch. The Taveyannaz basin was divided into two sub-basins by a thrust ramp palaeohigh running ENE/WSW (parallel to the thrust front). Palaeocurrent directions were trench parallel towards the ENE. Sedimentation in the Inner basin (140m thick) is characterised by very thick bedded turbidite sands generated by thrust induced seismic events confined within the thrust-top basin. The Outer basin (240m min. thickness) comprises 10-15 sand packages (5-100m thick) formed by turbidite sands which are commonly amalgamated. Sedimentation in the Outer basin is considered to have been controlled by thrust-induced relative sea-level variations. The Inner basin underwent intense deformation at the sediment/water interface prior to the emplacement of a mud sheet over the basin whilst the sediments were partially lithified. Later tectonic deformation involved fold and thrust structures detaching in the underlying Globigerina marls. The stratigraphy of the NAFB can be considered as two shallowing upward megasequences separated by the base Burdigalian unconformity. This stratigraphy can be simulated by computer by simplifying the foreland basin/thrust wedge system into 4 parameters: 1) the effective elastic thickness of the foreland plate, 2) a transport coefficient to describe the erosion, transport and deposition of sediment, 3) the surface slope angle of the thrust wedge, 4) the thrust wedge advance rate. The Alpine thrust wedge underwent thickening during the underplating of the External Massifs at about 24-18Ma. This event is simulated numerically by slowing the thrust wedge advance rate, and increasing the slope angle and keeping all other parameters constant. This event causes rejuvenation of the forebulge, and erosion of the underlying stratigraphy, so simulating the base Burdigalian unconformity without recourse to eustasy or anelastic rheologies to the foreland plate.
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Hines, Frederick Michael. "The sedimentation, tectonics and stratigraphy of the cretaceous/tertiary sequence of northwest Santander, northern Spain." Thesis, University of Oxford, 1986. http://ora.ox.ac.uk/objects/uuid:1d1f8c32-9fd3-44a5-ba6a-d963fa9868c0.
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The facies evolution of the Cretaceous/Tertiary sequence of NW Santander is considered in relation to the Cretaceous rifting and drifting, and Tertiary partial closure of the Bay of Biscay. Overlying the Palaeozoic basement are the fluvial Lower Triassic Buntersandstone and Upper Triassic Keuper evaporitic mudstone, deposited in a failed rift, extensional basin. Overlying Lower Jurassic carbonates are the syn-rift, continental elastics of the Vealden deposited in halfgrabens cut by transfer faults. The Vealden consists of two formations:- the lower, arenaceous-rich Barcena Mayor Fm. (braided stream environment) and the upper, argillaceous-rich Vega de Pas Fm. (meandering river). Overlying it is the Aptian Umbrera Fm. (calcarenite sheet), the Patrocinio Fm. (shoaling-up ward sandstone/marl alternation), the San Esteban Fm. (requienid/foraminiferal biomicrite of the internal platform) and the marls of the Rodezas Fm. The Upper Aptian Reocin Fm. is a requienid/foraminiferal biomicrite with thinned calcarenites deposited over active, diapiric palaeohighs. After initial marine and then equant calcite (meteoric phreatic) cementation, invasion of meteoric-derived groundwater over palaeohighs generated lenses of sucrosic dolomite in the Reocin Fm. Local mixing of further groundwater and Keuper-derived, sulphate-rich waters in karstic caverns precipitated sparry, baroque dolomite and Pb/Zn sulphides (by bacterial sulphate reduction). The clastic Lower Albian is a transgressive fluvial/estuarine/inner shelf sequence with tidal estuarine channels and sandwaves. The Middle/Upper Albian (syn-drift) has basal calcarenitic tidal sandwaves and is followed by storm/wave-reworked carbonates deposited on a homoclinal ramp. The clastic Lower Cenomanian is an estuarine/inner shelf deposit with tidal sandwaves and sandbars. The Middle/Upper Cenomanian is a storm/tide-dominated calcarenite. Outer shelf marls occur in the Turonian to Middle Campanian and the Upper Campanian to Middle Eocene is a sandy, foraminiferal inner shelf limestone. The Upper Eocene/Oligocene (syn-compression) is a carbonate slope-apron-reefal flysch deposit. It includes hemipelagic marl, neritic-derived calcarenitic turbidites and rudaceous mass flow deposits with highly polymict conglomerates. These were deposited coevally with Keuper piercement and thrust reactivation and date the Pyrenean compressional deformation here.
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Hill, Robert E. (Robert Einar). "Stratigraphy and sedimentology of the Middle Proterozoic Waterton and Altyn Formations, Belt-Purcell Supergroup, southwest Alberta." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63330.
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Alexander, Alan John. "Palynological, stratigraphic and chemical analyses of sediments in the Lothians with particular reference to the Lateglacial." Thesis, University of Edinburgh, 1985. http://hdl.handle.net/1842/10626.
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Palynological and stratigraphic investigations have been conducted on sediment cores for three sites in Lothian Region, Scotland: Balgone House, Broxmouth and Corstorphine. All phases of the Lateglacial period, as far as they are manifested in the Lothians at the sites studied, have been investigated with particular reference to the Younger Dryas, the main Interstadial, or Allerod, and also the evidence for the colder conditions that preceded it which are presumed to represent Older Dryas-type vegetation. Further light has been cast on the development of the Postglacial broad - leaved forests. The Cambridge computer program POLLDATA MKV was used to perform the necessary calculations and controlled a graph plotter to generate pollen diagrams. A series of subroutines is described that translated the calls to the Cambridge graphics subroutine library. This may serve as a model for other installations. Objective numerical zonation methods are applied to the pollen data. These methods are used not only to zone the pollen series but also to aid in the generation of hypotheses regarding vegetation changes. Chemical analyses of the sediments from Balgone House were undertaken. The results obtained are at variance with those from published work and it is proposed that the reason is that the chemical pre-treatment of samples employed locally may be less efficient in leaching the cations from the mineral fraction.
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Dal, Bo Patrick Francisco Fuhr. "Inter-relação paleossolos e sedimentos em lençois de areia eolica da Formação Marilia (noroeste da Bacia Bauru)." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/287354.
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Orientadores: Giorgio Basilici, Francisco Sergio Bernardes LadeiraDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociencias
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Resumo: A Formação Marília (Maastrichtiano), na faixa de afloramentos da porção noroeste da Bacia Bauru (estados de Goiás e Mato Grosso do Sul), é interpretada neste trabalho como um antigo sistema eólico de lençol de areia. A sucessão vertical é caracterizada por arenitos muito finos a médios intercalados com paleossolos em espessas sucessões de até 150 metros de espessura. A litofácies Arenito com laminação plano-paralela, que forma corpos com estratificação cavalgante transladante subcrítica, atribuída à deposição de areias com marcas onduladas eólicas é a mais comum descrita na área de estudos. Os paleossolos representam mais de 65% do registro geológico da Formação Marília, constituídos predominantemente por Aridisols caracterizados por concentrações secundárias de carbonato de cálcio. Superfícies suborizontais de deflação eólica separam os depósitos eólicos dos paleossolos e dividem a Formação Marília em duas fases distintas de construção de corpos geológicos ligadas às variações paleoclimáticas: i) fase de sedimentação eólica, caracterizada por depósitos arenosos de marcas onduladas eólicas; ii) fase de paleopedogênese, caracterizada por Aridisols. Ambas as fases se alternaram temporalmente e, registram períodos de formação de diferentes ordens de grandeza, provavelmente maiores que 105 vezes entre a formação dos depósitos arenosos com marcas onduladas eólicas e o desenvolvimento de horizontes Bk dos Aridisols. A alternância cíclica entre depósitos eólicos e paleossolos está ligada a variações paleoclimáticas que controlaram a disponibilidade hídrica no ambiente. Durante os períodos mais secos, a ausência de cobertura vegetal expôs a superfície à ação dos ventos e formação de extensas superfícies de deflação eólica, que posteriormente foram cobertas por depósitos arenosos de marcas onduladas eólicas. Com o posterior restabelecimento da umidade atmosférica e o conseqüente aumento da cobertura vegetal, a superfície foi reestabilizada, inibindo o processo de deflação e deposição eólica e permitindo a formação de Entisols e Aridisols
Abstract: The Marília Formation (Maastrichtian), outcropping in the northwestern portion of the Bauru Basin (Goiás and Mato Grosso do Sul brazilian states), is interpreted here as an ancient Aeolian sand sheet. The vertical succession, c.150 m thick, is made up of very fine to medium-grained sandstone and, it is characterised by cyclic interbedding of sediments and palaeosols. Planar laminated sandstone (subcritically climbing translatent stratification), formed by aeolian sand with wind ripple, is the most common lithofacies. Palaeosols, mainly Aridisols, represent more than 65% of the geological record of the Marília Formation. Subhorizontal aeolian deflation surfaces divide Marília Formation in two distinct constructional phases of geological bodies linked to palaeoclimatic variations: i) phase of prevalent aeolian sand deposition; ii) phase of Aridisols development. The two phases they alternated in time and probably record periods of formation with difference of the order greater than 105 between aeolian sand deposition and development of the Bk Aridisols horizons. Palaeoclimate is the main forcing factor of the Aeolian sand deposition and soil development. Episodes of sedimentation and soil development likely result from cyclic decreases and increases in available moisture and vegetation cover. Aeolian deflation and sedimentation were predominant during drier phases of past climatic cycles, when vegetation cover was sparse in source areas and windier conditions have the capacity to remove and transport clastic materials. During wetter phases of climatic cycles, increased vegetative cover stabilised the landscape, reduced deflation, and intensified Entisols and Aridisols development
Mestrado
Geologia e Recursos Naturais
Mestre em Geociências
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Callefo, Flávia 1983. "Análise tafonômica e paleoecológica de estruturas associadas a comunidades microbianas holocênicas e permianas." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/287739.
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Orientador: Fresia Soledad Ricardi Torres BrancoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências
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Resumo: Esteiras microbianas são estruturas organossedimentares laminadas, desenvolvidas a partir do acréscimo de lâminas de sedimentos aprisionados através do metabolismo de microrganismos, que induzem a precipitação de carbonato. Microbialitos são depósitos organossedimentares formados pela interação de microrganismos com sedimentos detríticos, através dos processos de trapeamento e aglutinação dos grãos e minerais. Esta pesquisa apresenta os resultados obtidos com o estudo tafonômico e paleoecológico de estruturas desenvolvidas por atividade de microrganismos, como estromatólitos, microbialitos e esteiras microbianas, com o intuito de comparar os resultados e traçar similaridades e diferenças nas relações ecológicas e ambientes de formação . Foram utilizados modelos recentes (Holoceno), como a Lagoa Salgada e Lagoa Pitanguinha, RJ, para compreender modelos fósseis (Permiano), afloramentos em Taguaí e Santa Rosa do Viterbo, SP. A metodologia se constituiu em análise de sedimentos associados, petrografia, análises composicionais (como MEV/EDS e Espectroscopia Raman) e estudo de campo. Foram levados em consideração os aspectos ambientais e biota contemporânea ao crescimento e desenvolvimento dos microbiais. As principais conclusões obtidas foram que os ambientes apresentam similaridades com relação a biota desenvolvida, bem como as relações ecológicas que estas mantinham com as comunidades microbianas responsáveis pelo desenvolvimento dos microbialitos e esteiras microbianas. O ambientes de crescimento das estruturas eram marinhos de águas rasas e hipersalinas, com o clima quente e alta taxa de evaporação. A alternância de eventos de tempestades e águas calmas, com posterior período de calmaria no qual foi possível o desenvolvimento de esteiras microbianas foram evidenciados no afloramento de Taguaí e na Lagoa Pitanguinha. Os microbialitos recentes da Lagoa Salgada sofreram maior influência de atividade de predação e herbivoria por parte de invertebrados, o que pode ter sido um fator relevante para a limitação do crescimento destas estruturas em comparação com aquelas existentes em Santa Rosa do Viterbo
Abstract: Microbial mats can be defined as laminated organosedimentary structures developed from the addition of laminaes of sediments trapped trough microorganisms metabolism, which leads to carbonate precipitation. Microbialites are organosedimentary deposits generated by the interation between microorganisms and detritic sediments through trapping and agglutination of minerals and grains play a key role. This research present the results of taphonomic and paleoecological studies from of structures developed by the activity of microorganisms such as microbialites, stromatolites and microbial mats aiming to comparison between the results obtained and to map similarities and differences on the ecological relations and formation environments. Recent models such as Salgada Lagoon and Pitanguinha Lagoon (Holocene), both located on Rio de Janeiro, were used to understand permian fossils models, outcrops located in Taguaí and Santa Rosa do Viterbo/SP. The methodology was based on the analysis of associated sediments, petrography and compositional analysis (MEV/EDS and Raman Spectroscopy) besides field studies. Aspects such as recent environments and biotas were considered to the analysis. The main conclusions were that the environments present similarities based on the development of the biotas as well as the ecological relations which those developed within the microbial communities responsible for the development of the microbialites and microbial mats. The growth environments of the structures were classified as shallow marine hypersaline waters, with warm weather and high evaporation rates. There was an alternation between storm events and calm waters. The growth of microbial mats became possible when the waters were predominantly calm evidenced by the outcrops from Taguaí and Pitanguinha Lagoon. The recent microbialites from Salgada Lagoon had a greater influence by activities from predators and herbivorous organisms such as invertebrates, which may be a relevant factor for the limitation growth of these structures when compared with those founded at Santa Rosa do Viterbo
Mestrado
Geologia e Recursos Naturais
Mestra em Geociências
Books on the topic "Geology, Stratigraphic Geology Geology Sedimentation and deposition"
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Michael, Weber. Spätquartäre Sedimentation am Kontinentalrand des südöstlichen Weddellmeeres, Antarktis =: Late Quaternary sedimentation at the continental margin of the southeastern Weddell Sea, Antarctica. Bremerhaven: Alfred-Wegener-Institut für Polar- und Meeresforschung, 1992.
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A, Davis Richard. Depositional systems: An introduction to sedimentology and stratigraphy. 2nd ed. Englewood Cliffs, N.J: Prentice Hall, 1992.
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Blumenstengel, Horst. Revidierte Stratigraphie tertiärer Ablagerungen im südlichen Sachsen-Anhalt =: Revised stratigraphy of tertiary deposits in the southern part of Sachsen-Anhalt. Halle (Salle): Institut für Geologische Wissenschaften und Geiseltalmuseum der Universität Halle, 1996.
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Droste, John Brown. Patterns of deposition during the early Pennsylvanian (Morrowan) in the Illinois Basin. Bloomington, Ind: Indiana Geological Survey, Indiana University, 2000.
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Pabian, Roger K. Late Paleozoic cyclic sedimentation in southeastern Nebraska: Field guide. Lincoln: Conservation and Survey Division, Institute of Agriculture and Natural Resources, University of Nebraska--Lincoln, 1991.
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1941-, Thiede Jörn, ed. History of Mesozoic and Cenozoic sediment fluxes to the North Atlantic Ocean. Stuttgart: Schweizerbart, 1985.
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Willemse, Nico W. Arctic natural archives. Utrecht: Koninklijk Nederlands Aardrijkskundig Genootschap, Faculteit Ruimtelijke Wetenschappen Universiteit Utrecht, 2000.
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Dahlstrom, David J. Fluvial architecture of the Lower Cretaceous Lakota Formation, southwestern flank of the Black Hills uplift, South Dakota. [Washington, D.C.]: U.S. G.P.O., 1995.
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Posamentier, H. W., R. D. Erskine, and R. M. Mitchum. "Models for Submarine-Fan Deposition within a Sequence-Stratigraphic Framework." In Frontiers in Sedimentary Geology, 127–36. New York, NY: Springer New York, 1991. http://dx.doi.org/10.1007/978-1-4684-8276-8_6.
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Johnson, N. M., Khalid A. Sheikh, Elizabeth Dawson-Saunders, and Lee E. McRae. "The Use of Magnetic-Reversal Time Lines in Stratigraphic Analysis: A Case Study in Measuring Variability in Sedimentation Rates." In Frontiers in Sedimentary Geology, 189–200. New York, NY: Springer New York, 1988. http://dx.doi.org/10.1007/978-1-4612-3788-4_9.
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Collins, D. R., and J. H. Doveton. "Automated Correlation Based On Markov Analysis Of Vertical Successions And Walther's Law." In Computers in Geology - 25 Years of Progress. Oxford University Press, 1994. http://dx.doi.org/10.1093/oso/9780195085938.003.0015.
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Walther's Law of Facies (1894) states that facies overlying one another comformably were formed in geographically contiguous environments. This vertical-lateral linkage is the basis for our automated method of stratigraphic correlation. The probabilities of vertical adjacency of different lithologies are estimated by embedded Markov chain analysis of sequences to be correlated. These probabilities are transformed to dissimilarities and used as elements within a dynamic programming sequence comparison. Trajectory tracking of cumulative thicknesses between the two sequences provides an auxiliary criterion to incorporate factors of sedimentation rate and compaction. Stratigraphic correlation is simultaneously simple and complex. The operation is fundamentally one of pattern recognition, whose principles can be grasped easily by any geology student. One source of complexity is caused by the fact that most successions are composed of a relatively small number of distinctive rock types. Within each succession, they are ordered as a linear chain in which loosely repetitive sequences are often perceived as "cycles" or "rhythms." As a result, the correlation between two adjacent successions may be ambiguous, so that several competing alternatives may be equally valid candidates for the "true" correlation. The situation is made still more disma! by the knowledge that erosional events may have removed entire stratigraphic segments and that periods of non-deposition may have caused gaps. In the opinion of Ager (1973), the gap is more important than the record. Even if a "complete" lithology record were available, it is unlikely that the successions in two separate locations would be identical. Lateral facies changes result in differences of lithology within correlative intervals. Equivalence or "similarity" of rock type is not the only criterion used in correlation. Thicknesses are a secondary source of information for correlation decisions. Similarity in thickness of equivalent lithologies between successions often implies a greater likelihood of their correlation. However, exceptions to this rule commonly are observed in the lateral thinnings and thickenings caused by both lateral facies changes and differential compaction. The simpler aspects of correlation suggest that practical automated correlation procedures are both feasible and desirable. Even if programmed decisions cannot be characterized absolutely as "objective," they can at least be made consistent.
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"Stratigraphic and Paleontologic Studies, Structural Controls of Sedimentation." In The Geology of the Mexican Republic. American Association of Petroleum Geologists, 1994. http://dx.doi.org/10.1306/st39586c6.
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Kelly, S. B., and J. M. Cubitt. "Milankovitch Cyclicity In The Stratigraphic Record— A Review." In Computers in Geology - 25 Years of Progress. Oxford University Press, 1994. http://dx.doi.org/10.1093/oso/9780195085938.003.0016.
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The Milankovitch or astronomical theory of paleoclimates relates climatic variation to the amount of solar energy available at the Earth's surface. The theory helps explain periodic, climatically related phenomena such as the Pleistocene ice ages. Identification of Milankovitch cyclicity within sediments demonstrates the influence of climate on sedimentation patterns and creates a time frame for the estimation of basin subsidence rates. Spectral analysis of deep sea and ice cores indicates periodic climatic fluctuations during Tertiary and Quaternary times. These fluctuations are strongly cyclical with low frequencies centered at periods around 400 ka and 100 ka together with shorter periodic components of approximately 41 and 21 ka. Lower frequencies reflect eccentricity of the Earth's orbit; 41- and 21-ka components are associated with periodic changes in the tilt of the Earth's axis and the precession of the equinoxes. Astronomically forced glacial eustasy results in distinct stratigraphic units or parasequences of widespread extent. Milankovitch band parasequences occur in both carbonate and clastic shelf systems, including cyclothemic Upper Paleozoic successions of North America. During the 1920's and 30's the Serbian mathematician Milutin Milankovitch studied cyclical variations in three elements of the Earth-Sun geometry: eccentricity, precession, and obliquity, and was able to calculate the Earth's solar radiation history for the past 650 ka (Milankovitch, 1969). Berger (1978, 1980) accurately determined the periodicities of the three orbital variations. Eccentricity—The Earth's orbit around the Sun is an ellipse; this results in the seasons. The eccentricity of the Earth's orbit periodically departs further from a circle and then reverts to almost true circularity. Periodicities are located around 413, 95, 123, and 100 ka. Secondary peaks appear to be located around 50 and 53 ka. There are further important periodicities at 1.23, 2.04, and 3.4 ma (Schwarzacher, 1991). Precession—Precession refers to variation in time of year at which the Earth is nearest the Sun (perihelion). This variation is caused by the Earth wobbling like a top and swiveling on its axis. Periodicities of 23,000, 22,400, 18,980, and 19,610 yr are recognized and often simplified to two periods of 19 and 23 ka. Secondary peaks are also located around 30 and 15 ka.
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Schwarzacher, W. "Can The Ginsburg Model Generate Cycles?" In Computers in Geology - 25 Years of Progress. Oxford University Press, 1994. http://dx.doi.org/10.1093/oso/9780195085938.003.0017.
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The Ginsburg model of carbonate accumulation is an often-quoted mechanism for generating so-called autocycles. It is shown that the model does not represent a self-oscillating system; oscillations can only be generated if at least two critical parameters controlling sedimentation are introduced. The Ginsburg model is a conceptual model which tries to explain the behavior of some carbonate shelves that undergo continuous tectonic subsidence and that carry on their surface a very active carbonate factory. Unfortunately the original model has only been published in abstract form—the relevant part of which is quoted here in full (Ginsburg, 1971, p. 340): . . . "The Florida Bay lagoon and the tidal flats of the Bahamas and Persian Gulf are traps for line sediment produced on the large adjacent open platforms or shelves. The extensive source areas produce carbonate mud by precipitation and by the disintegration of organic skeletons. The carbonate mud moves shoreward by wind-driven, tidal or estuarinelike circulation, and deposition is accelerated and stabilized by marine plants and animals. Because the open marine source areas are many times larger than the nearshore traps, seaward progradation of the wedge of sediments is inevitable. This seaward progradation gives a regressive cycle from open marine shelf or platform to supratidal flat. As the shoreline progrades seaward the size of the open marine source area decreases; eventually reduced production of mud no longer exceeds slow continuous subsidence and a new transgression begins. When the source area expands so that production again exceeds subsidence a new regressive cycle starts.". . . The author is very grateful to Dr. Ginsburg for supplying some additional information that is not obvious from the abstract. The subsidence must be differential and a broad, open shelf that gradually tilts seaward is visualized. All of the sediment produced on the shelf is transported shoreward, where it accumulates as a wedge-shaped deposit that builds into a tidal bank. A further analysis of the model is interesting for two reasons. First, the model has been and still is seriously suggested as a possible mechanism to explain cyclicity on carbonate platforms (see Goldhammer et al, 1987, for references).
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Wagner, J. Ross, Alan Deino, Stephen W. Edwards, Andrei M. Sarna-Wojcicki, and Elmira Wan. "Miocene stratigraphy and structure of the East Bay Hills, California." In Regional Geology of Mount Diablo, California: Its Tectonic Evolution on the North America Plate Boundary. Geological Society of America, 2021. http://dx.doi.org/10.1130/2021.1217(15).
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ABSTRACT The structure and stratigraphy of the Miocene formations east of San Francisco Bay have been described in multiple studies for over a century. We integrated the results of past investigations and provide new data that improve understanding of formation age, the timing of deformation, and the amount of dextral displacement on selected faults. New geologic mapping and better age control show that formations previously inferred to be separate units of different ages are correlative, and new names are proposed for these units. Miocene structures associated with the development of the San Andreas transform system exerted significant control on Miocene deposition in the East Bay area. The developing structure created five distinct stratigraphic sections that are differentiated on the basis of differences in the stratigraphic sequence, lithology, and age. The stratigraphic changes are attributed to significant dextral displacement, syndepositional faulting, and distal interfingering of sediment from tectonically elevated source areas. New stratigraphic evaluations and age control show that prior to ca. 6 Ma, the developing fault system created local tectonically induced uplift as well as spatially restricted subbasins. Regional folding did not occur until after 6 Ma. Past evaluations have inferred significant dextral displacement on some of the faults in the East Bay. The spatial relationships between unique conglomerate clasts and known source areas, as well as the distribution of well-dated and unique tuffs, suggest that dextral displacement on some faults in the East Bay is less than previously reported.
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Sullivan, Raymond, Morgan D. Sullivan, Stephen W. Edwards, Andrei M. Sarna-Wojcicki, Rebecca A. Hackworth, and Alan L. Deino. "Mid-Cenozoic succession on the northeast limb of the Mount Diablo anticline, California—A stratigraphic record of tectonic events in the forearc basin." In Regional Geology of Mount Diablo, California: Its Tectonic Evolution on the North America Plate Boundary. Geological Society of America, 2021. http://dx.doi.org/10.1130/2021.1217(13).
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ABSTRACT The mid-Cenozoic succession in the northeast limb of the Mount Diablo anticline records the evolution of plate interactions at the leading edge of the North America plate. Subduction of the Kula plate and later Farallon plate beneath the North America plate created a marine forearc basin that existed from late Mesozoic to mid-Cenozoic times. In the early Cenozoic, extension on north-south faults formed a graben depocenter on the west side of the basin. Deposition of the Markley Formation of middle to late? Eocene age took place in the late stages of the marine forearc basin. In the Oligocene, the marine forearc basin changed to a primarily nonmarine basin, and the depocenter of the basin shifted eastward of the Midland fault to a south-central location for the remainder of the Cenozoic. The causes of these changes may have included slowing in the rate of subduction, resulting in slowing subsidence, and they might also have been related to the initiation of transform motion far to the south. Two unconformities in the mid-Cenozoic succession record the changing events on the plate boundary. The first hiatus is between the Markley Formation and the overlying Kirker Formation of Oligocene age. The succession above the unconformity records the widespread appearance of nonmarine rocks and the first abundant appearance of silicic volcanic detritus due to slab rollback, which reversed the northeastward migration of the volcanic arc to a more proximal location. A second regional unconformity separates the Kirker/Valley Springs formations from the overlying Cierbo/Mehrten formations of late Miocene age. This late Miocene unconformity may reflect readjustment of stresses in the North America plate that occurred when subduction was replaced by transform motion at the plate boundary. The Cierbo and Neroly formations above the unconformity contain abundant andesitic detritus due to proto-Cascade volcanism. In the late Cenozoic, the northward-migrating triple junction produced volcanic eruptive centers in the Coast Ranges. Tephra from these local sources produced time markers in the late Cenozoic succession.
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Sarna-Wojcicki, Andrei M. "Late Cenozoic paleogeographic reconstruction of the San Francisco Bay area from analysis of stratigraphy, tectonics, and tephrochronology." In Regional Geology of Mount Diablo, California: Its Tectonic Evolution on the North America Plate Boundary. Geological Society of America, 2021. http://dx.doi.org/10.1130/2021.1217(17).
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ABSTRACT The Neogene stratigraphic and tectonic history of the Mount Diablo area is a consequence of the passage of the Mendocino triple junction by the San Francisco Bay area between 12 and 6 Ma, volcanism above a slab window trailing the Mendocino triple junction, and crustal transpression beginning ca. 8–6 Ma, when the Pacific plate and Sierra Nevada microplate began to converge obliquely. Between ca. 12 and 6 Ma, parts of the Sierra Nevada microplate were displaced by faults splaying from the main trace of the San Andreas fault and incorporated into the Pacific plate. The Mount Diablo anticlinorium was formed by crustal compression within a left-stepping, restraining bend of the eastern San Andreas fault system, with southwest-verging thrusting beneath, and with possible clockwise rotation between faults on its southeast and northwest sides. At ca. 10.5 Ma, a drainage divide formed between the northern Central Valley and the ocean. Regional uplift accelerated at ca. 6 Ma with onset of transpression between the Pacific and North America plates. Marine deposition ceased in the eastern Coast Range basins as a consequence of the regional uplift accompanying passage of the Mendocino triple junction, and trailing slab-window volcanism. From ca. 11 to ca. 5 Ma, andesitic volcanic intrusive rocks and lavas were erupted along the northwest crest of the central to northern Sierra Nevada and deposited on its western slope, providing abundant sediment to the northern Central Valley and the northeastern Coast Ranges. Sediment filled the Central Valley and overtopped the Stockton fault and arch, forming one large, south-draining system that flowed into a marine embayment at its southwestern end, the ancestral San Joaquin Sea. This marine embayment shrunk with time, and by ca. 2.3 Ma, it was eventually cut off from the ocean. Fluvial drainage continued southwest in the Central Valley until it was cut off in turn, probably by some combination of sea-level fluctuations and transpression along the San Andreas fault that uplifted, lengthened, and narrowed the outlet channel. As a consequence, a great lake, Lake Clyde, formed in the Central Valley at ca. 1.4 Ma, occupying all of the ancestral San Joaquin Valley and part of the ancestral Sacramento Valley. The lake rose and fell with global glacial and interglacial cycles. After a long, extreme glacial period, marine oxygen isotope stage (MIS) 16, it overtopped the Carquinez sill at 0.63 Ma and drained via San Francisco valley (now San Francisco Bay) and the Colma gap into the Merced marine embayment of the Pacific Ocean. Later, a new outlet for Central Valley drainage formed between ca. 130 and ca. 75 ka, when the Colma gap closed due to transpression and right-slip motion on the San Andreas fault, and Duxbury Point at the south end of the Point Reyes Peninsula moved sufficiently northwest along the San Andreas fault to unblock a bedrock notch, the feature we now call the Golden Gate.
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Holliday, Vance T. "Soil Stratigraphy." In Soils in Archaeological Research. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780195149654.003.0008.
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Soils have been employed in archaeological stratigraphy since at least the 1930s, including topical discussions of the significance of soils in stratified deposits (e.g., Leighton, 1936, 1937; Bryan and Albritton, 1943). This apparently was for several reasons. The unique physical and chemical properties that distinguish soils from sediments make soils quite useful for stratigraphic subdivision and correlation. In particular, pedologic features, most notably soil horizons, are often the most visually prominent features in stratified deposits. Furthermore, much of the early archaeological pedology was done by individuals trained in Quaternary geology (e.g., Leighton, 1937; Bryan, 1941a; Bryan and Albritton, 1943; Movius, 1944, pp. 49–62), in which soils have been recognized as stratigraphically important since the late 19th century (Bowen, 1978, pp. 10–56; Finkl, 1980; Tandarich, 1998a). The recognition of soils and the differentiation of soils from sediments in archaeological contexts is one of the most fundamentally significant aspects of geoarchaeological stratigraphy. This initial step in stratigraphic interpretation is crucial to most of the applications of pedology and soil geomorphology discussed in subsequent chapters. Because soils indicate periods of stability or hiatuses in deposition, the identification of soils or the lack thereof in a stratigraphic sequence provides information on the number of depositional episodes and intervals of stability. The identification of specific soil horizons also provides clues to the degree and duration of soil development, the nature of the soil-forming environment, and the kinds of soil-forming processes that may affect the archaeological record. Further, tracing of soils from exposure to exposure is a key aspect of correlating strata and interpreting the evolution of archaeological landscapes. This chapter presents a discussion of some principals of soil stratigraphy, and the following chapter focuses on the archaeological significance of soils as stratigraphic units. This chapter begins with a discussion of basic stratigraphy, which is one of the fundamental components of field-based geoscience. That section is followed by a closer look at soil stratigraphy, including a summary of both formal and informal soil stratigraphic nomenclature as well as a discussion of the unique characteristics of soils when used as stratigraphic markers and their archaeological implications.
Conference papers on the topic "Geology, Stratigraphic Geology Geology Sedimentation and deposition"
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Wu, Ivan Zhia, Sarvagya Parashar, Banu Andhika, Susan Syahdina, Arrie Kurniawan, Yoga Wismoyo, and Muhammad Ardhyan Jannatan. "Sand Body Trend Delineation Decrypting from Stratigraphic Dip Pattern Analysis: Case Study within a Fluvio-Deltaic Setting, East Kalimantan, Indonesia." In International Petroleum Technology Conference. IPTC, 2021. http://dx.doi.org/10.2523/iptc-21466-ms.
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Abstract During field development, a detailed understanding of reservoir geometry and associated sedimentary features within the sand sequence plays an important role in the effective recovery of hydrocarbon resources. Most aging fields encounter the common problem in well placement for effective production of the remaining hydrocarbon resources. The current example—onshore formation from Late Miocene in East Kalimantan—includes seismic data acquired during the 1970s and 1980s. Considering advancements and breakthroughs provided by current technology, the older information could provide a greater level of subsurface uncertainty. Geological challenges include comprehending geometry prediction and the continuity of the amalgamated distributary reservoir channels and the depositional architecture within a fluvio-deltaic environment in a structurally complex field. High-density borehole microresistivity image data from several wells in the study area were acquired to constrain and reduce the geological uncertainty resulting from poor control of subsurface imaging through the surface seismic data. Microresistivity imaging data were used to identify sedimentary features and to perform electrofacies analysis. The data are used for the structural reconstruction of sequences by decoding a different order of structural deformation and reconstructing the sediment transport direction at the time of deposition. The results are then incorporated within the regional geology context in the basin. The consistent shale/silt beddings in the studied wells indicate an overall structural dip trend of 10° toward the east. The structural deformation within the same section of these wells is identified by the characteristics in the rotation of the structural dips. This suggests the proximity of these wells in relation to the deformation plane of sub seismic features and helps refine the structural maps. During a later phase, the reservoir is correlated within the wells, and careful selection of a palaeocurrent indicator is established from the vertical distribution of the sedimentary beddings for paleogeography reconstruction. Based on this, the channel complex dispersal direction was observed to exhibit an overall easterly direction with complex migration, and the identified mouth bar sequences reveal more widespread geometry. The dispersion or variations observed in the studied wells are then correlated to the overall reservoir architecture within fluvio-deltaic settings. The case study demonstrates the applications of borehole microresistivity data and their importance in providing a high-resolution well-to-well correlation for sand body delineation within the targeted sequences. The results provide details about the structural complexity in the underlying subsurface litho-sequence and illustrate how behaviors change laterally from one well to another. This analysis helps develop a high-resolution geocellular model for the field.