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1
Jolly, Richard J. H. "Mechanisms of igneous sheet intrusion." Thesis, University of Southampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242207.
Testo completo
2
Esfarjani, H. R. "Engineering properties of basic igneous rocks." Thesis, University of Newcastle Upon Tyne, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374739.
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3
Student, James John. "Silicate Melt Inclusions in Igneous Petrogenesis." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/28719.
Testo completoAbstract (sommario):
Silicate melt inclusions are ubiquitous in quartz phenocrysts, yet there are few studies of such inclusions from porphyry copper systems. A melt inclusion forms when magma is trapped in a growing phenocryst. If a phenocryst is able to preserve the original parent magma, then accurate information can be obtained for ancient volcanic systems. In recent igneous systems, melt inclusions are commonly preserved as optically clear homogeneous glass representative of magma stored at depth before eruption. Melt inclusions are difficult to recognize in quartz phenocrysts from porphyry copper system because they are crystalline and hidden by exsolved magmatic volatiles. The inclusions range in size from less than 5 to over 150 μm. In order to evaluate the magmatic contribution to economic mineralization, we conducted three separate studies to determine whether or not crystallized melt inclusions preserve representative samples of magma.
The first study modeled the phase relationships that occur during equilibrium crystallization and melting of haplogranite magma trapped in quartz. Results from the model are similar to observations made during the heating of crystallized melt inclusions from porphyry copper systems. It is necessary to re-melt the crystal and volatile phases before chemical analysis. Micro-explosions caused by heating resulted in the loss of important chemical components. Our second study evaluated several microthermometric heating procedures using synthetic melt inclusions trapped at conditions similar to those inferred for porphyry copper systems. A synthetic hydrous melt was saturated with saline hydrothermal solutions allowing both melt and aqueous fluids to be trapped in quartz. Based on microthermometric measurements from these coeval melt and aqueous fluid inclusions we were able to predict the known trapping temperature and pressure of formation. This technique can be applied to natural samples to constrain trapping pressures and temperatures. It was found that slower heating rates could be used to avoid overheating and that heating under a confining pressure greatly minimizes the decrepitation of inclusions.
The third study examined the copper concentrations in melt inclusions from the Red Mountain, Arizona porphyry copper system. Older andesite magma contains pyroxene with melt inclusions of higher copper concentrations compared to melt inclusions in quartz from quartz latite. The higher water concentrations in crystallized melt inclusions in the quartz, and abundant aqueous fluid inclusions indicates that the exsolution of water from the magma occurred prior to the trapping of melt inclusions in quartz. The lower water concentrations and the absence of aqueous fluid inclusions indicates that the andesite never reached the stage of water exsolution. The results obtained here are consistent with models that suggest that copper is extracted from the melt by saline magmatic fluids, producing a metal-charged hydrothermal solution and leaving behind a metal-depleted melt and serves to identify the potential contribution of melt inclusion studies to constrain the origin of ore metals in porphyry copper deposits.<br>Ph. D.
4
Pattison, Christopher Ian. "Igneous intrusions in the Bowen Basin." Thesis, Queensland University of Technology, 1990. https://eprints.qut.edu.au/35967/1/35967_Pattison_1990.pdf.
Testo completoAbstract (sommario):
Igneous intrusions, in the form of stocks, sills and dykes are abundant in the Bowen Basin. They are predominantly Early Cretaceous in age, exclusively epizonal in origin and range in composition from dolerite to granodioriteldacite. All rock units within the
basin, up to and including the Clematis Group, are intruded to some degree. This study assesses the distribution, form, petrology and mode of emplacement of plutons, igneous sills and dykes occurring in the Bowen Basin, and considers their relationship to
the prevailing structure. The tectonic implications of the findings are then assessed. Igneous sills occur in two geographically distinct domains, one in the northern Bowen Basin and the other in the central Bowen Basin. The sills emanated from pre-existing, north to north-northwest trending reverse faults, and preferentially intruded coal seams.
The boundaries to sill intrusion are marked by major northeast trending basement
structures. These basement structures occur at regular intervals throughout the basin, and correspond with the localisation of plutonic and dyke activity, anomalous structural disturbance, and changes in the gross structure of the basin. They are interpreted as
transfer faults that were inherited from an Early Permian, basin-forming extensional
episode. Petrological evidence indicates that the plutons and sills occurring in the northern Bowen Basin are petrogenetically related, and that a progressive variation in their chemistry occurs across the axis of the basin from east to west. Intrusions in the east belong to the calc-alka1ine rock suite, while those in the west belong to the syenitic suite. This
transition is inte1preted in terms of increased crustal contamination as the magma migrated from a source area to the east along a buried, shallow-dipping detachment
surface that extends under the basin. This detachment was inherited from the above mentioned extensional phase and is intimately linked to structures that penetrate
up-section through the basin succession.
Reactivation of the transfer faults during the Early Cretaceous initiated the emplacement of dykes, and the synchronous development of northeast trending normal and wrenchstyle faults. The dykes exhibit characteristics that indicate they were self-propagating, and can be regarded as good palaeostress indicators. This phase corresponded with a major compressional event that involved the reactivation of pre-existing thrust structures, deformation of the Folded Zone and eastern margins of the Nebo Synclinorium and Mimosa Syncline, and the rapid preferential uplift of the central Bowen Basin region.
5
Jurinski, Joseph B. "Petrogenesis of the Moosehorn igneous complex, Maine." Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-04072010-020130/.
Testo completo
6
Reichow, Marc K. "Permo-Triassic igneous rocks of Siberia, Russia." Thesis, University of Leicester, 2004. http://hdl.handle.net/2381/7669.
Testo completoAbstract (sommario):
Widespread basaltic volcanism occurred in the region of the West Siberian Basin (WSB) and the Taimyr Peninsula in central Russia, and voluminous A-type magmatism within the Mongolian-Transbaikalian belt in southeast Siberia, during Permo-Triassic times. New 40Ar/39Ar age determinations on plagioclase grains from deep boreholes in the WSB reveal that the basalts were erupted at ~250 million years ago. This is synchronous with the main period of the Siberian Traps volcanism, which was located farther east. The age and geochemical data presented confirm that the WSB basalts are part of the Siberian Traps, and at least double the confirmed area of the volcanic province as a whole. The larger area of volcanism strengthens the link between the volcanism and the end-Permian mass extinction. Furthermore, it is argued that the WSB and Taimyr basalts are genetically related to the Siberian Traps basalts, especially the Nadezhdinsky Suite found at Noril’sk. This suite immediately preceded the main pulse of volcanism that extruded lava over large areas of the Siberian Craton. Magma volume and timing constraints strongly suggest that a mantle plume was involved in the formation of the Earth’s largest continental flood basalt province. The Mongolian-Transbaikalian granitoid belt covers over 600,000 km2 with over 350 single A-type plutons. New U-Pb geochronological data presented here demonstrate that no plutonic complex dated is 250 Ma old. Although mantle-derived material played a prominent role in the granitoid generation, these melts may have been generated by processes other than decompressional melting within the head of a mantle plume. The new U-Pb ages and other observations contradict the idea of a relation between the Siberian plume and magmatic activity in the territory of Transbaikalia. An alternative preferred model inducing up rise of asthenospheric material includes slab break-off after a long period of subduction.
7
Rainey, Michelle M. "Microfractures in the weathering of igneous rock." Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239231.
Testo completo
8
Singletary, Steven J. (Steven James) 1973. "Igneous processes of the early solar system." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/58444.
Testo completoAbstract (sommario):
Thesis (Ph. D. in Geochemistry)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, February 2004.<br>Includes bibliographical references.<br>Experimental, petrographic and numerical methods are used to explore the igneous evolution of the early solar system. Chapters 1 and 2 detail the results of petrographic and experimental studies of a suite of primitive achondritic meteorites, the ureilites. The first chapter presents data that reveal correlations between mineral modal proportions and mineral chemistry that are used to guide experiments and models of ureilite petrogenesis. Chapter 2 details and applies the experimental results to describe ureilite petrogenesis as the result of progressive heating of a primitive carbon-rich body. The experiments place temperature and depth constraints on uteilite formation of 1100 to 13000C and 5 to 13 MPa - equivalent to the central pressure of an asteroid with a radius of 130 km. Chapter 3 reports the results of melting experiments of Allende carbonaceous chondrite at temperatures and pressures that would be expected on small bodies in the early solar system (up to 1300⁰C and 2.5 to 15 IPa) heated by decay of short lived isotopes. The results are then applied to ureilite petrogenesis and assembly of larger planetary bodies. The final chapter is an experimental study to test a hybridized source region for the high titanium lunar ultramafic glasses. Two models are presented that invoke either a heterogeneous source region or sinking and reaction of an ultramafic, titanium rich magma with underlying mantle regions.<br>by Steven J. Singletary.<br>Ph.D.in Geochemistry
9
Marchand, Kateri. "Étude d'éléments structuraux dans la demie nord du Canton de McKenzie, Chibougamau /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1990. http://theses.uqac.ca.
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10
Mainville, Michèle. "Les komatiites et tholéiites à la base du groupe de baby, Témiscamingue /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1994. http://theses.uqac.ca.
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11
Vieira, Nuno Manuel Martinho. "Petrologia e aspetos geoquímicos das rochas ácidas do tipo Palmas e Chapecó da Província Magmática do Paraná /." Rio Claro, 2017. http://hdl.handle.net/11449/151077.
Testo completoAbstract (sommario):
Título: Petrologia e aspetos geoquímicos das rochas vulcânicas ácidas tipo Palmas e Chapecó da província magmática do Paraná<br>Orientador: Antonio José Ranalli Nardy<br>Banca: João Manuel Lima da Silva Mata<br>Banca: Fábio Braz Machado<br>Resumo: As rochas ácidas da Província Magmática do Paraná (PMP) cobrem cerca de 2,5% do volume total do vulcanismo intracontinental ocorrido durante o Cretáceo Inferior, o que levou à abertura do Atlântico Sul. As análises petrográficas e o estudo da química mineral dos principais constituintes minerais, plagioclásio, piroxênio (orto e clino) e Ti-magnetita, das rochas ácidas do tipo Palmas (ATP) e ácidas tipo Chapecó (ATC), permitiram obter dados inéditos e correlacionar, com maior rigor, os vários magmas-tipo que essas rochas geraram. Foi possível descriminar a mineralogia distinta do grupo Palmas, ao que diz respeito aos cristais de piroxênio, assim como as heterogeneidades geoquímicas deste mesmo grupo e de Chapecó. Ortopiroxênio é exclusivo das rochas ATP e especificamente do magma-tipo Caxias do Sul. Os clinopiroxênios, pigeonita e augita são comuns em todos os subtipos das ácidas, porém, esta última está ausente da associação mineralógicas das rochas do magma-tipo Santa Maria (ATP). Com o estudo detalhado da relação mineralógica entre os cristais permitiu inferir sobre a sequência de cristalização dos piroxênios e, por conseguinte das rochas tipo Palmas. As feições texturais, dados de química mineral e (raros) de geotermobarometria obtidos nas rochas ATP e ATC sugerem que os minerais presentes nestas rochas não estão em equilíbrio com o líquido que gerou a rocha hospedeira. As feições petrográficas encontradas nos cristais de piroxênio e plagioclásio, tais como, bordas corroíd... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: The acid rocks of the Paraná Magmatic Province (PMP) cover about 2.5% of the total volume of intracontinental volcanism that occurred during the Lower Cretaceous, which led to the opening of the South Atlantic. Petrographic analyzes and the study of mineral chemistry of the main Palmas acid type (ATP) and Chapecó acid type rocks (ATC), made it possible to obtain unpublished data and correlate, with greater rigor, the various types of magmas these rocks generated. It was possible to discriminate the mineralogy distinct from the Palmas group, as regards the pyroxene crystals, as well as the geochemical heterogeneities of this group and Chapecó group. Orthopyroxene crystals are unique to ATP rocks and specifically to the Caxias do Sul magma-type. Clinopyroxenes crystals, pigeonite and augite, are very common in all acidic subtypes, but the latter is absent from the mineralogical association of the Santa Maria magma-type rocks (from ATP). With the detailed study of the mineralogical relationship between these crystals allowed us to infer about the crystallization sequence of the pyroxenes and, consequently, of the Palmas group. The textural features, mineral chemistry data and (rare) geothermobarometry data obtained in the ATP and ATC rocks suggest that the minerals present in these rocks are not in equilibrium with the liquid that generated the host rock. The petrographic features found in pyroxene and plagioclase crystals, such as corroded edges, corona and matrix impregnation,... (Complete abstract click electronic access below)<br>Mestre
12
Wilkinson, D. R. "Repeated igneous activity through continental lithosphere, central Portugal." Thesis, University of Reading, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356494.
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13
Pilote, Pierre. "Stratigraphie et significations des minéralisations dans le secteur du mont Bourbeau, canton de McKenzie, Chibougamau /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1986. http://theses.uqac.ca.
Testo completoAbstract (sommario):
Mémoire (M.SC.A.)--Université du Québec à Chicoutimi, 1986.<br>"Mémoire présenté en vue de l'obtention de la maîtrise en sciences de la terre" Cartes contenues dans une pochette. CaQCU CaQCU Document électronique également accessible en format PDF. CaQCU
14
Chen, Qinfang. "Geophysical and radiometric investigation of weathered igneous rocks in Hong Kong /." Hong Kong : University of Hong Kong, 2002. http://sunzi.lib.hku.hk/hkuto/record.jsp?B23621497.
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15
Therriault, Ann Marie. "Petrogenesis of the Sudbury Igneous Complex: The shocking story." Thesis, University of Ottawa (Canada), 2001. http://hdl.handle.net/10393/6378.
Testo completoAbstract (sommario):
The Sudbury Structure, Ontario, is the remnant of a 1.85 Ga old impact crater, 200--250 km in diameter. Erosion and tectonism have affected the Sudbury Structure and resulted in considerable brittle and ductile deformation, and the removal of the surface expression of the crater structure and all exterior deposits typical of many terrestrial impact structures. However, substantial amounts of the interior deposits, including the craterfill products, have been preserved within the Sudbury Basin. Although most workers acknowledge an impact origin for the Sudbury Structure, the origin of the Sudbury Igneous Complex (SIC), located inside the Sudbury Structure, remains controversial. The objectives of this study are to elucidate the division of the SIC into lithologically separate phases and to understand their relation to impact and endogenic igneous processes by using physical, chemical and computer methods, and to model the genesis of the SIC. The SIC is a 2.5--3.0 km thick, ∼60 x 27 km elliptical igneous-rock body, consisting of four major lithologies (top to base): granophyre, quartz gabbro, norite, and the so-called contact sublayer. All these lithologies are continuous across the complex, except for the contact sublayer. Modal compositions reveal that the current nomenclature is improper. According to the IUGS classification, "quartz gabbro" samples should be classified as quartz monzogabbros and "norite" samples as quartz gabbros or quartz monzogabbros. In view of these observations, an updated terminology is proposed (top to base): upper unit, transition zone, middle unit, lower unit, and contact sublayer. Gradational mineralogical and geochemical variations between the SIC lithological units are evidence of a single melt system for the SIC. The occurrence of primary hydrous minerals, deuteric alteration, and abundant micrographic and granophyric intergrowths demonstrate that this melt was rich in H 2O. The intergrowths and other far-from-equilibrium textures are likely due to rapid crystallization as a result of a large undercooling caused by the exsolution of a volatile phase. The SIC differs from other known terrestrial impact melt sheets only by its great thickness and its chemical layering. It is concluded that the SIC is a differentiated impact melt sheet, the only one identified on Earth to date.
16
Severs, Matthew Jeremiah. "Applications of Melt Inclusions to Problems in Igneous Petrogenesis." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/28310.
Testo completoAbstract (sommario):
Understanding the different igneous processes that magmas undergo is important for a variety of reasons including potential hazards associated with volcanoes in populated regions, magmatic hydrothermal ore deposition, and tectonic processes. One method of obtaining geochemical data that can help constrain petrogenetic processes is through the study of melt and fluid inclusions. The research presented here examines melt inclusions through experimental, analytical and field studies to better understand igneous petrogenesis.
One potential problem associated with melt inclusions is water-loss during laboratory heating. A Raman spectroscopic technique was developed to determine water contents of silicate glasses, and this technique was applied to monitor water loss from natural melt inclusions that were heated for varying lengths of time. The results suggest that water loss is insignificant when heated for less than 12 hours but significant water loss can occur with longer duration heating.
The distribution of trace elements between silicate melts and phenocrysts growing from that melt can constrain igneous processes such as fractional crystallization, assimilation, and partial melting. Partition coefficients were determined for syngenetic clinopyroxene, orthopyroxene, and plagioclase in equilibrium with a dacitic melt using the Melt Inclusion-Mineral (MIM) technique. Melt inclusion chemistry is the same regardless of mineral host phase, suggesting that the melt inclusions have not been subjected to re-equilibration processes or boundary layer development. Partition coefficients from this study are similar but typically lower than published values.
Three closely-spaced monogenetic eruptive units from the active Campi Flegrei volcanic system (Italy) with similar eruptive styles were examined to better understand the evolution of the magmatic system. Results suggest fractional crystallization as the dominant process taking place over time but that magma mixing was significant for one of the eruptions. Trace element geochemical data suggest a mixed magma source of within-plate and volcanic arc components, and still retain a T-MORB signature from the subducting slab.<br>Ph. D.
17
Pattie, Andrew J. D. "Hybridization of basic wall rocks in xenolithic igneous complexes." Thesis, Aston University, 1989. http://publications.aston.ac.uk/14371/.
Testo completo
18
Riter, Joyce Christine Alexis. "Geochemical and tectonic evolution of the Colorado Plateau mantle lithosphere : evidence from Grand Canyon mantle xenoliths /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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19
Newman, Rowena Jane. "Igneous and hydrothermal minerals and textures in the offshore Canterbury Basin." Thesis, University of Canterbury. Geological Sciences, 2015. http://hdl.handle.net/10092/10856.
Testo completoAbstract (sommario):
The Canterbury Basin is located on a passive margin on the east coast of the South Island, developed by the rifting of the New Zealand continental fragment from Antarctica in the Late Cretaceous. Well cuttings produced during petroleum exploration in the offshore Canterbury Basin have been examined for secondary minerals and textures. Minerals and textures have been identified primarily from optical examination in reflected light, with a particular focus on producing high-resolution images. Additional identifications are made using thin sections, SEM, XRD and XRF analysis.
The focus of this study is the Clipper-1 well in the Clipper sub-basin as it contains the most abundant mineralisation and covers the full depth of the Canterbury Basin sedimentary sequence. Examination of cuttings from this well has revealed intrusive igneous carbonates and native metals including iron, aluminium and copper. The trace element concentrations in the igneous carbonates indicates they are derived from crustal material. Textures indicating fluidisation and recrystallisation of sedimentary material are also present.
The proposed mechanism for producing these unusual mineral assemblages is a late Pliocene or younger mafic intrusion into the schist basement of the Canterbury Basin. The igneous carbonates are inferred to be derived from melting of carbonates in the schist. The native metals have been produced from melt due to highly reducing conditions produced by interaction of the intrusion with coal and limestone. The combination of native metals and igneous carbonates with a conspicuous absence of typical silicate igneous rocks is inferred to represent a new type of intrusive environment that has not previously been described in the scientific literature.
20
Lee, Paula M. "Spatial, temporal, and petrogenetic relationship of basaltic and lamprophyric dikes and sills of the Raton Basin, southern Colorado and northern New Mexico." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/5848.
Testo completoAbstract (sommario):
Thesis (M.S.)--University of Missouri-Columbia, 2005.<br>The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (July 11, 2006) Includes bibliographical references.
21
Getson, Jacqueline. "Effect of plagioclase crystallization on liquid and magma viscosity in the Anorthite-diopside-dorsterite-quartz system." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4628.
Testo completoAbstract (sommario):
Thesis (M.S.) University of Missouri-Columbia, 2006.<br>The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (June 25, 2007) Includes bibliographical references.
22
Rabae, Abdussalam. "Geophysical investigations of the Anglo-Brabant Massif." Thesis, University of Bristol, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386227.
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23
Jarvis, Richard Allan. "Crystallization and melting in geological fluid mechanics." Thesis, University of Cambridge, 1991. https://www.repository.cam.ac.uk/handle/1810/275236.
Testo completo
24
La, Rocque Cynthia A. "Geochronology and petrology of north-central Gaspe igneous rocks, Quebec." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65499.
Testo completo
25
Hole, Malcolm John. "Time controlled geochemistry of igneous rocks of the Antarctic Peninsula." Thesis, Royal Holloway, University of London, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423458.
Testo completoAbstract (sommario):
Four distinct groups of intrusive rocks have been identified within Graham Land, northern Antarctic Peninsula. Each Group is defined on the basis of age, Sr-, Nd- and a-isotopic and trace element geochemical signatures. Group I intrusions are dominantly Tertiary and are geographically restricted to the W coast of the Peninsula, and exhibit low initial e7Sr/e6Sr and high initial 14~Nd/144Nd ratios (0.7038 - 0.7045 and 0.51280 0.51277). Group I intrusions possess the lowest LIL/HFS ratios of any Group with Th/Ta and La/Ta ratios similar to N-type MORB, and may exhibit a distinct alkaline affinity; they are considered to have been emplaced during a Tertiary supra-subduction zone extensional episode. Cretaceous Group II granitoids crop out throughout Graham Land. Group III and IV granitoids range from late Triassic - Jurassic and are restricted to central eastern Graham Land and SE Graham Land respectively. Sr- and Nd-isotope characteristics of Group III and IV intrusions are consistent with base of crust (~35 Km) interaction between a mantle derived magma and pre-TriaSSiC, but not necessarily ancient, continental crust. Group III granitoids possess consistent e7Sr /e6Sr and 14~Nd/144Nd ratios (0.7060 - 0.7070 and ~ 0.5123 respectively). Group IV intrusions are more highly contaminated (initial e7Sr /e6Sr and 14~Nd/144Nd ratios 0.7078 - 0.7162 and 0.5123 - 0.5120 respectively), and were probably intruded through thicker crust than Group III. LIL/HFS and LREE/HREE ratios increase with increasing degrees of contamination.- Isotope and trace element characteristics of Antarctic Peninsula intrusions reflect changes in tectonic regime with time; pre-Triassic tectonic segmentation of Graham Land resulted in the varying degrees of contamination of Groups III and IV, while syn-subduction extension resulted in the emplacement of isotopically uncontaminated Group I intrusions, with calc-alkaline to alkaline affinities.
26
Sargeant, Fiona. "The seismic stratigraphy of the Bushveld Igneous Complex, South Africa." Thesis, University of Liverpool, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250322.
Testo completo
27
Gooday, Robert James. "The formation and evolution of the Central Arran Igneous Complex." Thesis, Cardiff University, 2019. http://orca.cf.ac.uk/119175/.
Testo completoAbstract (sommario):
The Central Arran Igneous Complex - a system of intrusive and pyroclastic volcanic rocks - is one of the least understood onshore 'central complexes' of the British Palaeogene Igneous Province (BPIP). The BPIP is part of the wider North Atlantic Igneous Province, formed during opening of the North Atlantic Ocean and the arrival of the Iceland plume at the base of the lithosphere. Despite being known about for over a century, the magmatic and volcanic processes that formed the Central Arran Igneous Complex remain poorly understood. The Central Arran Igneous Complex comprises a number of granitic and dioritic intrusions, a caldera-fill succession of pyroclastic and sedimentary rocks intruded by a dolerite sill, and a series of dykes ranging in composition from picrite to pitchstone. This study uses a combination of field mapping, whole-rock elemental geochemistry, radiogenic isotope geochemistry, and U-Pb zircon geochronology to determine how these units and their magmas formed, how they relate to one another, and their relationship with other igneous rocks throughout the BPIP. Detailed study of the intra-caldera stratigraphy allows a prolonged volcanic history to be pieced together, with pyroclastic units separated by erosional surfaces indicating periods of volcanic quiescence and sedimentary processes. Following the initial period of caldera collapse, which was accompanied by highly explosive eruptions, volcanism was generally less explosive and formed abundant high-grade and lava-like ignimbrites. The majority of magmas were derived from a mantle source compositionally transitional between N-MORB and the Iceland plume. Geochemical differences between the mafic units are derived from different degrees of melting, from different source regions. All magmas show some degree of crustal contamination by various units, and their isotope geochemistry can be used to constrain the poorly understood crustal architecture in the region. U-Pb zircon geochronology shows that magmatism in central Arran took place over a very short space of time. The difference in interpreted 206Pb/238U ages between the oldest (Allt Ruadh Member ignimbrites; 58.92 ± 0.19 Ma) and the youngest (granitic Glenloig Hybrids; 58.71 ± 0.07 Ma) dated units is ≤ 470 kyr.
28
Anderson, Paul. "Zonation and emplacement of the Newry igneous complex, Northern Ireland." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/6265/.
Testo completoAbstract (sommario):
The Newry Igneous Complex (NIC) in Northern Ireland comprises three largely granodioritic plutons, together with an intermediate-ultramafic body at its northeast end. Geochronology shows that the NIC becomes broadly younger to the southwest and towards the centres of individual plutons. Geophysical results from the recent Tellus Survey of Northern Ireland have been combined with petrology and geochemistry to establish 17 distinct zones within the NIC, which are interpreted to represent separately intruded magma pulses. A combination of Anisotropy of Magnetic Susceptibility (AMS), petrographical and field data shows that the NIC was emplaced as a series of laccoliths into a tension-releasing bend on a strike-slip fault. This regime is proposed to have been facilitated by two deep-seated crustal lineaments. Inflation is suggested to have occurred due to magma pressure during emplacement of each individual zone. At least five constituent parts of the NIC are interpreted to have been emplaced separately at successively higher crustal levels. Thus the intrusion is thought to represent a series of stacked laccoliths, produced by a southwestward migrating source.
29
Macdonald, Raymond. "Petrological studies of igneous rocks, mainly from continental extensional zones." Thesis, University of Edinburgh, 1987. http://hdl.handle.net/1842/12500.
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30
Lang, James Robert. "Isotopic and geochemical characteristics of Laramide igneous rocks in Arizona." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185600.
Testo completoAbstract (sommario):
Isotopic and trace element data on igneous rocks in nine multiphase magmatic complexes of Laramide age in Arizona place constraints on their petrogenesis and on the factors leading to the formation of porphyry copper deposits. The igneous rocks form a data array from ∊Nd(T) and Srₒ values of 0 and 0.704, to -14 and >0.710, respectively. Isotopic compositions indicate that early, intermediate volcanic rocks retained a mantle component whereas later intrusions were derived predominantly from Precambrian lower crust. The REE display temporally systematic behavior. Progressively younger igneous rocks in a district show a decreasing concentration of REE which is more pronounced for the HREE than for the LREE; they acquire greater upward concavity in their HREE profiles; and the Eu anomaly steadily becomes less negative. An increasing role for hornblende is indicated, either in the residuum of melting or as a fractionating phase. The evolving REE and isotopic behavior parallels the progression from barren, to subproductive, to productive intrusions. The geochemical behavior can be understood in the broader context of magmagenesis at the Laramide convergent margin. Early in the Laramide, the crust was cool and brittle, thereby allowing magmas formed in the mantle wedge as a consequence of volatile loss from the descending slab to ascend to high crustal levels. As the crust warmed the ascent of mantle-derived magmas was arrested in the lower crust where they induced anatexis in Precambrian crust. Three related models can account for the systematic REE behavior, crustal anatexis, and the timing of Laramide metallogenesis: (1) metasomatism of the lower crust, (2) progressively greater assimilation of hydrous crust by mantle-derived melts, and (3) migration of the anatectic zone into more hydrous rocks at higher crustal levels. Each process would allow melting to continue in confined columns of crust as well as provide increasingly volatile-rich magmas that were necessary for melts to evolve fluids capable of forming large porphyry copper deposits. The ultimate ability of a melt to form a porphyry copper deposit may, therefore, depend on characteristics obtained either in its crustal source region or during its passage through the crust.
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Côté, Denis. "Pétrographie, pétrologie et étude géochimique du dyke de diorite, de l'intrusion troctolitique et des deux petits massifs anorthositiques de Canton Taché /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1986. http://theses.uqac.ca.
Testo completoAbstract (sommario):
Mémoire (M.Sc.A.)--Université du Québec à Chicoutimi, 1986.<br>"Mémoire présenté à Chicoutimi en vue de l'obtention d'une maîtrise en science appliquée (géologie)" CaQCU Bibliogr.: p. 129-134. Document électronique également accessible en format PDF. CaQCU
32
Péloquin, Alice Shirley. "The petrographic and geochemical variations in archean meta-basaltic pillows from the Kinojevis Group of the Abitibi Greenstone Belt, Rouyn-Noranda, Québec = Les variations pétrographiques en géochimiques des coussins basaltiques archéens du groupe de Kinojevis, sous-province de l'Abitibi, Rouyn-Noranda, Québec /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1990. http://theses.uqac.ca.
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Knox, Katherine Lee. "The Never Summer Igneous Complex: Evolution of a shallow magmatic system." Diss., Connect to online resource, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1433514.
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Funk, Jonathan Andrew. "Anhydrite-bearing igneous breccias in the El Teniente copper deposit, Chile." Diss., Connect to online resource, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1439445.
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Chiang, Kai Kim. "The geochemistry of Cenozoic igneous rocks of Borneo and tectonic implications." Thesis, Royal Holloway, University of London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399226.
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陳琴芳 and Qinfang Chen. "Geophysical and radiometric investigation of weathered igneous rocks in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31242947.
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Al-Jawadi, A. F. "Minor igneous intrusions of the Lake District : geochronology, geochemistry and petrology." Thesis, University of Newcastle Upon Tyne, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376308.
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Roberts, S. "The role of igneous processes in the formation of ophiolitic chromitite." Thesis, Open University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374493.
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Clark, Samantha Jean. "Constraining diagenetic timings, processes and reservoir quality in igneous-affected basins." Thesis, Durham University, 2014. http://etheses.dur.ac.uk/10827/.
Testo completoAbstract (sommario):
As the demand for hydrocarbons increases, more complex, non-conventional plays have been targeted in volcanic margin settings. Consequently, it is important to understand the role igneous rocks have in affecting hydrocarbon systems. This is particularly relevant to the Rosebank Field, offshore UK Continental Shelf, North Atlantic. The field was discovered in 2004 with the 213/27-1z well and encountered Palaeogene volcanic rocks interbedded with siliciclastic and volcaniclastic rocks, representing a brand new play type. Three appraisal wells were drilled and encountered good quality light oil (37° API) with drill steam tests achieving ~ 6000 STB per day (Duncan et al., 2009). Initially four companies had a stake in the field; Chevron (40%), Statoil (30%), OMV (20%) and Dong (10%) however in 2011, OMV bought out Statoil leaving them with a 50% stake. Chevron remain the operators. The importance of volcaniclastic sediments within these sequences has previously been overlooked and so a better understanding of how these rocks behave during burial is essential. This research quantitatively characterises and assesses the reservoir potential of a range of volcaniclastic and siliciclastic sedimentary rocks within such basins. The Rosebank Field comprises a range of volcaniclastic lithic arenites and lava flows interbedded with sublithic arenites and quartz arenites. However samples could only be taken from limited the limited cores. This made interpreting 3D architecture difficult and therefore it was decided that a onshore analogue was required. The Staffa Formation of the Palaeogene Mull Lava Field, NW Scotland, provides an excellent analogue to the Rosebank Field within the Faroe-Shetland Basin. It comprises basaltic lava flows interbedded with a variety of volcaniclastic and sedimentary rocks. A range of rock types occur within the Staffa Formation, including vent-proximal pyroclastic rocks, such as massive scoria rich tuffs to re-worked volcaniclastic lithic arenites to vent-distal facies where the siliciclastic component begins to dominate, such as quartz arenites. The Staffa Formation has therefore, been compared and contrasted to the Rosebank rocks to better understand composition, burial history and reservoir potential. Detailed characterisation of the volcaniclastic rocks has been undertaken using a variety of analytical techniques (optical microscopy, SEM and XRD), and demonstrates that volcanic material in potential reservoir rocks may significantly reduce their reservoir quality. Proximal pyroclastic rocks, which can have reasonably good porosity and permeability at the surface, degrade to non-reservoir values at shallow depths (<1km), as reactive volcanic components alter to both grain-coating and pore-filling clays during diagenesis. This process dominates diagenesis meaning that it only requires small proportions of volcanic material to be incorporated within a sediment to destroy its porosity. In some cases, alteration is so severe that the original rock textures and clast outlines are lost, making the rock difficult to identify. Several generations of pore-filling and grain-coating clays, formed from the alteration of volcanic glass, including gel and fibrous palagonite, Fe-smectite and chlorite, have been identified in the volcaniclastic rocks samples from both the Rosebank core and the Staffa Formation. The nature of the volcanic material plays an important role in a rock’s ability to retain reservoir quality. Factors such as the composition, shape and grain size of volcanic clasts in these rocks affect how the sediment behaved during diagenesis. Spatter bombs and scoria, for example, react differently clasts derived from lava. Labile volcanic ash shards that underwent minimal surface reworking altered to fibrous clay, and were then flattened and moulded around framework grains during diagenesis and burial. This reduced the local porosity and permeability in the rocks. Clay alteration of weathered basaltic clasts resulted in the development of pseudomorph grains that preserved the original grain structure and had only a minimal effect on surrounding pore throats. Clay formation in these rocks was extremely heterogeneous and highly dependent on the immediate grain-scale mineralogy. Clay phases developed during early diagenetic stages blocked or altered later fluid pathways, which led to an extremely patchy diagenetic mineralogy. Rocks inferred to be located at more distal locations from the vent have higher proportions of siliciclastic components and somewhat simpler paragenetic sequences that are characterised by carbonate and silicic cements and minimal authigenic clays. Oxygen and hydrogen isotopic data provide constraints on pore water chemistry and temperatures during diagenesis. Together, these data have been used to determine the diagenetic histories of the Rosebank Field and Staffa Formation, and enabled the development of a conceptual model to determine the threshold at which volcaniclastic rocks are no longer viable as petroleum reservoir rocks. The model shows that volcaniclastic rocks containing more than 10% volcanic clasts are likely to have very poor reservoir quality at depth. However, this is dependent on a number of factors such as clast size, clast type, depositional setting, sorting, pore water composition and timing. These data will be of use in the assessment of potential plays in volcanic rifted margins worldwide.
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Dahrén, Börje. "Magma plumbing architecture in Indonesia and the North Atlantic Igneous Province." Doctoral thesis, Uppsala universitet, Mineralogi, petrologi och tektonik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-267764.
Testo completoAbstract (sommario):
Magma plumbing systems represent the physical framework of magma transport and storage from the source region in the mantle, through the crust, until reaching the surface in a volcanic eruption. Characterising the different aspects of magma plumbing, in particular the distribution of magma storage zones throughout the crust, is of key importance to better understand the behaviour of individual volcanoes. In particular, shallow crustal magma storage and associated magma-crust interaction processes could potentially explain some of the worlds most unpredictable and explosive volcanoes. This thesis studies magma plumbing architecture in the Sunda Arc (Indonesia), and the North Atlantic Igneous Province, based on elemental and isotope geochemistry, and derived petrological modelling. In this study, I have employed petrological models, so called geothermobarometers, to calculate pressures and temperatures (P-T) of crustal magma storage. Geothermobarometers are calibrated thermodynamic formulations based on the composition of magmatic minerals and their co-existing melt as a function of the P-T conditions of crystallisation. Using the calculated P-T estimates, I was able to derive the depth of magma storage, and thereby reconstruct the architecture of magma storage systems. A number of different geothermobarometers based on different mineral phases, including plagioclase, clinopyroxene and olivine, were used for this purpose, The geothermobarometric modelling was combined with additional elemental and isotope geochemical analyses, as well as collaborations with geophysical investigations. These additional approaches were used to corroborate the findings of the geothermobarometric modelling, and also to model and quantify magma-crust interaction processes that take place during crustal magma storage, such as assimilation of crustal lithologies into the magmatic system. The findings of this thesis build upon the growing body of evidence in support of the prevalence of shallow magma storage in different volcanic settings worldwide. This realisation is relevant to volcano monitoring and hazard mitigation worldwide.
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Caunt, Stephen Lloyd. "Igneous and metamorphic processes in the Shap Granite and its aureole." Thesis, University of Leeds, 1986. http://etheses.whiterose.ac.uk/522/.
Testo completoAbstract (sommario):
The Shap Granite outcrops in eastern Cumbria, N.W. England and is a post—orogenic granite intruded during the Lower Devonian (ie 394 Ma) into rocks of Ordovician to Siturian age. It is of adamellite composition and is notable in having megacrysts of orthoclase which crystallised late (relative to the matrix) by an essentially metasomatic process. Late in its cooling history, hydrothermal fluids resulted in alteration ano mineralisation in and about the joint structures. Comparison of whole — rock element and stable isotope data between the hydrothermally — altered and non —altered granites shows that this late — stage process- was isochemical and only involved localised redistribution of the available elements, the hydrothermal fluid being derived from the granite itself and acting in a closed system. The associated suite of granitic dykes extends the chemical range of Shap granitic rocks from the restricted compositions of the granite itsetf (around 68%)to 62 to 77% Si02. Mineralogical and chemical evidence suggests that the Shap magma compositions were controlled mainly by biotite and plagioclase fractionation over much of this silica range. The granite is intruded about much of its outcrop into rocks of the mid—Ordovician, calk—alkaline Borrowdatt Volcanic Group. The aureate is lkm wide and 'generally displays limited contact metamorphic reactions apart from in the Blue Quarry, where higher sub—surface heat flow during the granite's intrusion resulted in localised more extreme metamorphic and some metasomatic conditions resulting in the development of garnet veins. Analysis of 61 samples from the aureole region show only very limited modifications to their original calk—alkaline chemistry. Stable isotope and the whole rock geochemistry indicates that the contact metamorphism was essentialty, isochemical and that chemical interaction with the granite did not occur. Aureole metamorphic reactions took place at moderate temperatures (250 — 400°C) apart from in a narrow (<1000 zone about the granite contact where temperatures may have reached close to those of the granite-solidus (around 600°C). Xenoliths from the 'granite Pink quarries at Shap contain the same mineralogy as their host granite, including the megacryst orthoclase. The xenolith chemistry compares well with that of the more basic dykes, with the xenoliths - forming a coherent group over the compositional range 56 to 674 Sia. Comparison with the country—rock chemistry shows that the xenoliths were not externally derived but probably represent quenched, more basic, comaqmatic melts related to the generation of the main Shap Granite magma. Limited Sr and Nd isotope data for the xenoliths show that these isotopes were in equilibrium with the granite and lends strong support for the cogeneric origins and chemical relationships for the granites, aykes and xenoliths together. The narrow aureole width is typical of those formed by conductive ratner convective cooling with interaction with the adjacent granite limited to thermal effects and not involving the cycling of fluids through the granite or aureole as in convective pluton cooling.
42
Chan, Heung-ngai. "Igneous and metamorphic rocks from SW Cyprus and NW Syria evidence for Cretaceous microplate collision and subsequent tectonic events in the Eastern Mediterranean /." Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B30711940.
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Barker, Aaron Robert. "Predicting alluvial reservoir development and drainage distribution during mid to late large igneous province formation." Thesis, University of Aberdeen, 2016. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=231017.
Testo completoAbstract (sommario):
This research aims to better understand drainage systems during mid to late Large Igneous Province (LIP) formation. A multidisciplinary study was conducted on the Lewiston Basin in the Columbia River Flood Basalt Province and the Skye Lava Field in the North Atlantic Igneous Province. A general model for drainage systems in LIPs was developed with three stages. In the early-LIP stage, the volcanic and drainage systems are confined to small basins, but as the volumetric eruption rate increases the regional drainage system is forced to the edge of the lava field. During the mid-LIP stage, the eruption rate decreases and the drainage system moves into the lava field, depositing channel sediments in the lowest parts of province while finer sediments or palaeosols develop in topographically higher areas. In the Skye Lava Field the drainage system was dominated by the uplift of the Rum Central Igneous Complex and included the incision of shallow valleys, whereas in the Lewiston Basin the most important effect was the structural control on basin topography. During the lateLIP stage, topographically high areas experience significant incision into the lava field which are filled by intracanyon flows (thick canyon-filling lava flows). These intracanyon flows may compartmentalise potential reservoirs deposited between earlier lava flows. Siliciclastic sand bodies were observed up to 12 m thick and 850 m across with minor exposure gaps, and were correlated across up to 15 km. The palynofloras associated with a number of palaeoenvironments in each province were identified the effects of other controls on the palaeoecology such as moisture availability, ashfall and substrate were established. The changes in the paJaeoclimate of the Lewiston Basin were studied using palaeosol geochemistry and palynology.
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Gallagher, Brookie. "A comparative study of the Badger Pass igneous intrusion and the foreland volcanic rocks of the McDowell Springs area, Beaverhead county, Montana implications for the local late cretaceous sequence of events /." unrestricted, 2008. http://etd.gsu.edu/theses/available/etd-04212008-172506/.
Testo completoAbstract (sommario):
Thesis (M.S.)--Georgia State University, 2008.<br>Title from file title page. Timothy E. LaTour, committee chair; Hassan A. Babaie, Eirik J. Krogstad, William J. Fritz, committee members. Electronic text (111 p. : ill. (some col.), maps (some col.)) : digital, PDF file. Description based on contents viewed Aug. 20, 2008. Includes bibliographical references (p. 100-104).
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Huang, Kuan. "Geological studies of igneous rocks and their relationships along the Kyrenia Range, Northern Cyprus." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/b40204030.
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Church, Abigail Ann. "The petrology of the Kerimasi carbonatite volcano and the carbonatites of Oldoinyo Lengai with a review of other occurrences of extrusive carbonatites." Thesis, University College London (University of London), 1996. http://discovery.ucl.ac.uk/1349623/.
Testo completoAbstract (sommario):
Extrusive carbonatites are rare igneous rocks with just 37 known localities. The majority are calciocarbonatites, the principal exception being those of the active volcano, Oldoinyo Lengai, which are strongly alkaline. Unresolved questions concerning extrusive carbonatites include: 1. Why are extrusive carbonatites at Lengai chemically different from all others? 2. Could the extrusive calciocarbonatites originally have had alkaline compositions? In order to address these questions extrusive carbonatites from both Lengai and the adjacent volcano, Kerimasi, were collected and compared. A compilation of all the available data on known extrusive carbonatites is also presented. The major results documented in this thesis are: 1. Alkali carbonatites from Oldoinyo Lengai erupted in 1993 contain petrographic evidence for an origin by liquid immiscibility from a highly fractionated peralkaline silicate melt (wollastonite nephelinite). 2. The suite of silicate rocks at Kerimasi are derived from a primary olivine nephelinite by fractional crystallisation and cumulus processes. 3. Extrusive carbonatites at Kerimasi are not genetically related to the silicate suite. By contrast intrusive sovites also present, originated by liquid immiscibility from a primitive silicate magma, equivalent to a melilite, nephelinite, at low pressure. 4. Extrusive calciocarbonatites from Kerimasi were erupted directly from the mantle. They contain phenocrysts (previously interpreted as pseudomorphs after alkali carbonate) which are now thought to have been dolomite containing calcite exsolution lamellae. 5. Of the 35 other extrusive carbonatite occurrences, none show any petrographic or geochemical evidence of having originally being alkaline. Therefore extrusive carbonatites from Oldoinyo Lengai are thought to be unique. 6. Of the 37 extrusive carbonatites, 50% are associated with melilitites or melilitebearing rocks, 27% are associated with nephelinites and the remaining 23% were erupted with no associated silicate magmas.
47
Ormerod, D. S. "Late- to post-subduction magmatic transitions in the Western Great Basin, U.S.A." Thesis, Open University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233247.
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Röckl, Ludwig Otto. "The geology and genesis of a gold-rich, copper porphyry occurrence in the eastern Pontids, NE-Turkey." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246233.
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Moore, Kathryn Ruth. "Melting of a carbonated mantle." Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285716.
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Potgieter, J. E. "Anorogenic alkaline ring-type complexes of the Damaraland Province, Namibia, and their economic potential." Thesis, Rhodes University, 1987. http://hdl.handle.net/10962/d1001567.
Testo completoAbstract (sommario):
Anorogenic alkaline ring-type complexes form within continental plate settings. Alkaline magmatism is derived from the upper mantle, in which mantle metasomatism plays an important part, as well as from partial melting of the lower crust. Radial and concentric fractures develop during the ascent of alkaline magma. Extrusion of basic and felsic magma takes place along these fractures with felsic volcanics building-up central volcanoes. As a result of emptying of the magma chamber, the superstructure of the volcano collapses and a caldera is formed. During the caldera stage syenitic and granitic material are intruded into ring fractures. Alkaline ring-type complexes may be classified as (i) alkaline qranite and syenite-type and (ii) carbonatite and undersaturated-type. These ring-type complexes occur as distinct igneous provinces. Some major provinces occur in Brazil, Corsica, Namibia, Nigeria, Norway, Saudi-Arabia and Sudan. In Namibia the Damaraland igneous province is of Mesozoic aqe and it contains 15 alkaline ring-type complexes . These complexes are situated along north-eastern trends which correspond to transform directions of the South Atlantic. During the opening of the South Atlantic (Gondwana breakup) Pan-African age lineaments were reactivated which allowed emplacement of anorogenic alkaline magmatism. A zonation of alkaline granite and syenitetype in the west and carbonatite and undersaturated-type ring-complexes in the east correlates with down- and upwarp axes parallel to the line of Gondwana fragmentation. Alkali- and H⁺-metasomatism is related to the alkaline and syenite-type whereas alkali metasomatism (fenitization) is associated with carbonatite and undersaturated-type ring-complexes. Sn, W and Ta mineralization is associated with alkaline granites of some of the alkaline granite and syenite-type ring-complexes. Fe, F, PO₄ , Nb, Th, REE, Sr, Zn and Pb mineralization is associated with carbonatite complexes. Potential exists for: (i) porphyry Cu-Mo and epithermal-type (Au, Ag, Pt-metals, base metals) mineralization in the alkaline granite and syenite-type ring-complexes and (ii) disseminated Cu, Au, Aq and Pt-metals in carbonatite and undersaturated-type ring-complexes