Дисертації з теми "Geochronological"
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Milne, Alastair John. "The pre-Mesozoic geological evolution of Graham Land, Antarctica." Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253302.
Повний текст джерелаBoygle, Jane E. "Tephra in lake sediments : an unambiguous geochronological marker?" Thesis, University of Edinburgh, 1995. http://hdl.handle.net/1842/20193.
Повний текст джерелаCoombs, Henry. "Geochemical and geochronological constraints on terrane definition in Mexico." Thesis, Cardiff University, 2016. http://orca.cf.ac.uk/94626/.
Повний текст джерелаBendall, Betina R. "Metamorphic and geochronological constraints on the Kimban Orogeny, Southern Eyre Peninsula /." Title page, abstract and contents only, 1994. http://web4.library.adelaide.edu.au/theses/09SB/09sbb458.pdf.
Повний текст джерелаWhattam, Scott A. "Evolution of the Northland ophiolite, New Zealand: geochemical, geochronological and palaeomagneticconstraints." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B31244890.
Повний текст джерелаBowtell, Sophie Ann. "Geochronological and geochemical studies of Zermatt-Saas Fee Ophiolite, Western Alps." Thesis, University of Leeds, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305487.
Повний текст джерелаBailey, Simon David. "A geophysical and geochronological assessment of coastal dune evolution at Aberffraw." Thesis, Birkbeck (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.483553.
Повний текст джерелаPu, Judy (Judy P. ). "Geochronological constraints on the Trinity diamictite in Newfoundland : Implications for Ediacaran glaciation." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/114096.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (pages 21-26).
The Avalon terrane in Newfoundland includes the Ediacaran Gaskiers Formation, which has been associated with a Snowball glaciation event. The complicated regional stratigraphy and lack of precise geochronological constraints has made it difficult to determine the spatial and temporal extent of the Gaskiers glaciation. Recent recognition of a diamictite facies on the nearby Bonavista Peninsula correlative with the Gaskiers diamictite has allowed for new, high-precision geochronological constraints on the Gaskiers glaciation and constrains the duration of the event to less than 390 ±320 kyr. The Snowball Earth hypothesis requires that glaciation continued for several millions of years so that CO2 could build up to high enough levels in the atmosphere for catastrophic deglaciation; the short duration of the Gaskiers event makes it unlikely to have been a Snowball event. Further geochronological studies are needed to determine whether the Gaskiers glaciation was a discrete event or if it was a glacial maximum in a longer Ediacaran ice age.
by Judy Pu.
S.B.
Weller, Owen M. "An integrated metamorphic and geochronological study of the south-eastern Tibetan plateau." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:f4104b43-389a-4d54-bd7b-ba3fc0e8ab95.
Повний текст джерелаHelbing, Heiko. "No suture in the Sardinian Variscides a structural, petrological and geochronological analysis /." Tübingen : Univ, 2003. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10733113.
Повний текст джерелаGrodzicki, Kathryn R. "Structural, geochemical and geochronological analysis of the Coatlacco area, Acatlán Complex, southern Mexico." Ohio : Ohio University, 2006. http://www.ohiolink.edu/etd/view.cgi?ohiou1154628676.
Повний текст джерелаMuir, D. D. "Petrological and geochronological constraints on magma storage conditions beneath Uturuncu volcano, SW Bolivia." Thesis, University of Bristol, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619259.
Повний текст джерелаBorel, Megan E. "A Microstructural and Geochronological Investigation of the Coyote Mountain Metamorphic Core Complex (AZ)." Thesis, University of Louisiana at Lafayette, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=10814678.
Повний текст джерелаThe Coyote Mountains is a metamorphic core complex that makes up the northern end of the 80-km long Baboquivari Mountain complex. The Baboquivari Mountain complex is composed of Mesozoic rocks, Cenozoic granites, pegmatites, and metasediments (Wright and Haxel, 1982; Haxel et al., 1980, 1984). In the Coyote Mountains, there is an intrusion of the Pan Tak granite, a muscovite-biotite-garnet peraluminous granite dated at 58 Ma based on U-Pb analysis of zircon. The Pan Tak and other intrusions within the Baboquivari Mountains have been interpreted as anatectics melts representing the culmination of a Laramide crustal shortening orogenic event that started in the Late Cretaceous, about ~70 mya (Goodwin and Haxel, 1990). However, field evidence, as well as petrographic and microstructural analyses of metamorphic and deformational fabrics/structures show that the ~58 mya intrusive/magmatic fabric is overprinted by a secondary tectonic event. This event is particularly well recorded in the northern part of the Coyote Mountains, where a northdipping mylonitic shear zone is exposed. This study focuses on the Pan Tak granite with twenty samples from the northern portion of the Coyote Mountains, directly north of Coyote Peak, from the mapped areas of granites and mylonites.
Bailey, Simon David. "A geophysical and geochronological assessment of coastal dune evolution at Aberffraw, North Wales." Thesis, University of London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533191.
Повний текст джерелаGrodzicki, Kathryn. "Structural, Geochemical and Geochronological Analysis of the Coatlacco Area, Acatlan Complex, Southern Mexico." Ohio University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1154628676.
Повний текст джерелаPerlman, Zachary S. "STRATIGRAPHIC, GEOCHEMICAL, AND GEOCHRONOLOGICAL ANALYSIS OF THE WOLFCAMP-D INTERVAL, MIDLAND BASIN, TEXAS." UKnowledge, 2017. http://uknowledge.uky.edu/ees_etds/48.
Повний текст джерелаErickson, Timmons Manning. "Deformation microstructures in zircon and monazite: implications for shock, tectonic and geochronological studies." Thesis, Curtin University, 2016. http://hdl.handle.net/20.500.11937/51620.
Повний текст джерелаKröner, Stephan Ulrich Georg. "Geochronological and structural evolution of the western and central Kaoko Belt in NW Namibia." [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=976127385.
Повний текст джерелаRieuwers, Mark Thomas. "Thermobarometric and geochronological constraints on reworking of the Palaeoproterozoic Strangways Metamorphic Complex, central Australia /." Title page, contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09SB/09sbr564.pdf.
Повний текст джерелаPeters, D. "A geochemical and geochronological assessment of the Great Glen Fault as a terrane boundary." Thesis, Keele University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.344063.
Повний текст джерелаWong, Ping-mei Jean, and 王冰媚. "Geochemical and geochronological constraints on the Jiangshan-ShaoxingFault Zone in Zhejiang Province, Eastern South China." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B45983860.
Повний текст джерелаGeng, Hongyan, and 耿红燕. "Geochemical and geochronological studies of carboniferous magmatism inthe West Junggar: ridge subduction in thelate paleozoic?" Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45983999.
Повний текст джерелаMAUAD, CRISTIANE RIBEIRO. "GEOCHRONOLOGICAL VARIATIONS OF CARBON BLACK AND PAHS IN GUANABARA BAY AS INDICATORS OF COMBUSTION SOURCES." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2010. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=16588@1.
Повний текст джерелаAs pesquisas sobre carbono negro (BC) vêm ganhando grande importância nos últimos anos, não somente devido a sua capacidade de atuar como traçador histórico de processos de combustão em uma determinada região, mas também devido a sua capacidade de sorver contaminantes hidrofóbicos de ambientes aquosos. Buscou-se estudar a geocronologia de dois subprodutos provenientes de processos de combustão (BC e HPAs - hidrocarbonetos policíclicos aromáticos), que podem ter origem tanto de queima de biomassa quanto de combustíveis fósseis em um testemunho sedimentar coletado da região noroeste da Baía de Guanabara. Foram avaliadas suas possíveis relações, entre si e com o teor de carbono orgânico presente no sedimento. Avaliaram-se também as possíveis fontes dos HPAs presentes nas amostras, traçando um histórico de queima da região, caracterizada por um acentuado trafego veicular e poluição crônica por diversos compostos. O testemunho foi seccionados em intervalos de 2 cm, onde foram utilizados os segmentos entre 0-72 cm somando totalizando 30 amostras. A metodologia analítica utilizada para a determinação do BC foi a CTO-375, baseada na retirada da matéria orgânica (não-BC) por combustão na presença de oxigênio em excesso, restando somente a fração mais refratária composta pelo BC. Embora a variação percentual de BC tenha apresentado uma média de 0,36 (+-) 0,08 % p.s. ao longo do testemunho, foi observado que o mesmo compõe uma fração significativa do carbono orgânico total (TOC) desta região chegando a representar até 18% p.s. do TOC. A razão C/N possibilitou mostrar que grande parte de matéria orgânica presente neste local é proveniente de origem marinha. O método utilizado para a determinação da concentração dos HPAs foi o EPA 3540C, baseado na extração dos analitos da matriz, a purificação dos extratos através da remoção de interferentes. Através das razões diagnósticas e da análise de componentes principais (PCA) foi possível traçar uma transição das principais fontes de HPAs neste ambiente, mostrando a predominância de HPAs pirogênicos nas amostras mais antigas, para uma maior contaminação petrogênica nas amostras mais recentes. Ainda foi possível comprovar a afinidade de HPAs pirogênicos à presença de BC. Análises de microscopia eletrônica de varredura (SEM) contribuíram para uma maior compreensão das características morfológicas do sedimento, mostrando este ser rico em material amorfo e diatomáceas cêntricas. Esta análise também possibilitou a identificação visual da partícula de BC, porém, a falta de um pré-tratamento nas amostras dificultou o seu reconhecimento. Foram realizadas análises de ressonância magnética nuclear (CP/MAS (13)C NMR) visando possibilidades futuras de determinação de BC por esta técnica. As análises de NMR mostraram que o elevado teor de carbono aromático presente na amostra ambiental, relacionado principalmente a presença de lignina, interfere no sinal de NMR para a determinação de BC, sendo necessária a sua oxidação. Análises de CP/MAS-NQS (13)C NMR possibilitaram a separação das frações de BC, mostrando um teor acentuado de carbonos não-substituídos, sugerindo maior aporte de BC proveniente de queima ao longo do testemunho. Na amostra mais superficial, percebeu-se maior presença de carbonos quaternários, indicando o aumento no aporte de BC oriundo de combustão de combustíveis fósseis.
Researches about black carbon (BC) have been gaining importance in recent years, not only because of its ability to act as a tracer of historical combustion processes in a given region, but also for its ability to adsorb hydrophobic contaminants in aqueous environments. In a sediment core collected from the northwestern region of Guanabara Bay, was attempted to study the geochronology of two combustion sub-products processes (BC and PAHs - polycyclic aromatic hydrocarbons), which may originate both biomass burning and fossil fuels. Was evaluated their possible relationships between themselves and with the content of organic carbon in the sediment. Also was evaluated the possible PAHs sources in the samples, tracing a burning history in the region, characterized by a marked vehicular traffic pollution and chronic individual compounds. The core was sectioned at intervals of 2 cm, which were used from 0 to 72 cm segments, in a total of 30 samples. The BC analytical determination methodology was the CTO-375, based on organic matter (non-BC) removal by combustion in presence of excess oxygen, leaving only a fraction composed by most refractory BC. Although the BC percentage had an average of 0.36 (+-) 0.08% dry weight over the core, was observed that is a significant fraction of total organic carbon (TOC) in this place representing up to 18% d.w. of TOC. The C/N ratio permitted evaluate that much of organic matter on this site comes from sea sources. The method used for determining the concentration of PAHs was the EPA 3540C, based on the analytes extraction from the matrix, and the extracts purification through the interferences removal. Through diagnostic reasons and principal component analysis (PCA), were possible to evaluate a PAHs transition of the main sources in this environment, showing the PAHs predominance in older pirogenics samples to an increase of petrogenic contamination in the most recent samples. It was also possible to relate an affinity of PAHs pyrogens in the BC presence. Analysis of scanning electron microscopy (SEM) contributed to a better understanding about the sediment morphological characteristics, showing to be rich in amorphous material and centric diatoms. This analysis also allowed the visual identification of the BC particles, however, the lack of a pre-treatment in the samples made it difficult to recognize. Nuclear magnetic resonance (CP/MAS (13)C NMR) analysis were performed in order to future possibilities of BC determination by this technique. The NMR analysis showed that the high aromatic carbon content in the environment sample, is mainly related to the presence of lignin interferes with the signal of NMR for the determination of BC, which requires its oxidation. Analysis of CP/MAS-NQS (13)C NMR allowed the separation of fractions of BC, showing a strong level of carbon non-replaced, suggesting a greater contribution of BC from burning during the core. In the most superficial sample, it was observed the large presence of quaternary carbons, indicating an increase in the input of BC come from combustion of fossil fuels.
Dymoke, Peter Lindsay. "Geochronological and petrological studies of the thermal evolution of the Dalradian, South West Scottish Highlands." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/13754.
Повний текст джерелаHagemann, Lukas Falk [Verfasser], Jan [Akademischer Betreuer] Schwarzbauer, and Frank [Akademischer Betreuer] Lehmkuhl. "Geochronological investigations of anthropogenic contaminants in alluvial sediments / Lukas Falk Hagemann ; Jan Schwarzbauer, Frank Lehmkuhl." Aachen : Universitätsbibliothek der RWTH Aachen, 2020. http://d-nb.info/1225401615/34.
Повний текст джерелаHagemann, Lukas Falk Verfasser], Jan [Akademischer Betreuer] [Schwarzbauer, and Frank [Akademischer Betreuer] Lehmkuhl. "Geochronological investigations of anthropogenic contaminants in alluvial sediments / Lukas Falk Hagemann ; Jan Schwarzbauer, Frank Lehmkuhl." Aachen : Universitätsbibliothek der RWTH Aachen, 2020. http://d-nb.info/1225401615/34.
Повний текст джерелаGhassemi, Mohammad Reza. "Tectonic evolution of the Late Archean Pontiac Subprovince, Superior Province, Canada: Structural, metamorphic, and geochronological studies." Thesis, University of Ottawa (Canada), 1996. http://hdl.handle.net/10393/9932.
Повний текст джерелаViskupic, Karen M. (Karen Marie) 1975. "Crustal melting in the Himalayan orogen : field, geochemical and geochronological studies in the Everest region, Nepal." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/59101.
Повний текст джерелаIncludes bibliographical references.
A combination of field studies and geochemical techniques were used to investigate the timing and processes involved in leucogranite generation in the Everest region of the Himalayan orogen. Geochemical investigations focused on samples from three outcrops at different structural levels in the Himalayan metamorphic core where in situ crustal melting and multiple generations of leucogranite intrusions were observed. Accessory phase thermochronological and U-Pb geochronological studies were combined to determine the timing of anatexis in a migmatite at the structurally lowest outcrop. Quantitative measurement of REE and Y in monazites and xenotimes, that were later dissolved and dated by U-Pb IDTIMS, revealed monazite growth at temperatures appropriate for crustal melting (>650⁰C) between 25.4 and 24.8 Ma, suggesting that anatexis was ongoing at that time. Further constraints were placed on the timing of crustal melting, granite crystallization and cooling with a detailed U-Pb IDTIMS and 40Ar/39Ar study of leucogranite dikes, sills, and the metamorphic rocks they intrude. Backscattered electron imaging of accessory minerals provided important insights into the petrogenesis of monazite, xenotime and zircon, and guided efforts to isolate accessory phase growth domains. In two granitic sills, extensive accessory phase crystallization between ca. 26 and ca. 23 Ma was interpreted to be the result of episodic to semi-continuous melt generation and crystallization at least between those times. These melt products were later entrained in melts that crystallized as syntectonic sills at 21-22 Ma. Younger crosscutting dikes crystallized between 17.5 and 18.3 Ma.
(cont.) The range in accessory phase dates from these dikes and sills that represent magmatic crystallization ages spans from 26.2 to 17.5 Ma, providing evidence for melt generation in one region over roughly 9 million years. Neodymium isotopic signatures of the same monazite and xenotime grains dated by U-Pb IDTIMS were used to investigate melting processes and granite source-rock characteristics. The dominant control of monazite on the Nd isotopic composition of its host rock was clearly demonstrated. Some Nd isotopic heterogeneities recorded in monazite and in xenotime support a model for melt generation where accessory phases grow from locally derived sources in an isotopically heterogeneous melt.
by Karen M. Viskupic.
Ph.D.
Seydoux-Guillaume, Anne-Magali. "Experimental determination of the incorporation of Th into orthophosphates and the resetting of geochronological systems of monazite." Phd thesis, [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963521349.
Повний текст джерелаBrown, Hazel A. "A palaeomagnetic, geochronological and palaeoenvironmental investigation of late and post glacial maar lake sediments from NW-Europe." Thesis, University of Edinburgh, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.489316.
Повний текст джерелаHarris, Nancy Ruth 1970. "Isotopic, geochemical, and geochronological constraints on the origin and evolution of Cenozoic volcanism, Baikal Rift Zone, Siberia." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/54432.
Повний текст джерелаIncludes bibliographical references.
The Cenozoic Baikal Rift Zone, one of the world's major continental rifts, is expressed as an approximately 1800 km-long southwest-northeast oriented system situated along a suture between the Archean Siberian craton and younger Paleozoic fold belts. Oligocene to Recent age volcanic rocks and associated mantle xenoliths are distributed in three major regions of the rift zone: the Udokan volcanic field in the northeast, the Vitim volcanic field -200 km southeast of Lake Baikal, and a broad zone of volcanism to the southwest of Lake Baikal. This large-scale study investigates the geochemical evolution of the Baikal Rift Zone volcanism using major element, trace element, and isotopic (Sr, Nd, and Pb) geochemistry, as well as 40Ar/39Ar geochronology. In addition, a detailed isotopic study of megacrysts provides insight into the relationship between megacrysts and host lavas and the nature of the lithospheric mantle. Results of this study suggest that the source region for Baikal Rift Zone volcanic rocks is remarkably homogeneous considering the large region and time span over which these rocks erupted, and that crustal contamination has not been a significant controlling factor. The Tunka Basin, Oka Plateau, and Tuva volcanic fields in the western Baikal Rift Zone, and the Vitim volcanic field southeast of Lake Baikal, have a fairly restricted compositional range from basaltic andesite, alkaline basalt and hawaiite, to basanite and mugearite. In the Udokan volcanic field in the northeast, a more evolved series of rocks ranging to trachytic compositions erupted across the suture between the Archean craton and Paleozoic fold belts. Major and trace elements indicate that fractional crystallization of pyroxene, olivine, and plagioclase produced the observed range in compositions. The trace element and isotopic compositions of Baikal Rift Zone volcanic rocks are comparable to those observed in ocean island basalts. The Sr, Nd, and Pb isotope systematics can best be explained by mixing between the end-member mantle components DMM ( typical of the depleted source of MORB mantle) and EMI (enriched mantle type 1). Megacrysts of clinopyroxene, amphibole, garnet, biotite, and anorthoclase mirror the isotope systematics of the host volcanic rocks, and suggest that the megacrysts were derived from a melt closely related to their host rocks. Furthermore, megacrysts of clinopyroxene, as well as Cr-diopside from spinel lherzolites, have an unradiogenic Pb isotopic composition that may be representative of the EMI-like composition of the subcontinental lithospheric mantle.
by Nancy Ruth Harris.
Ph.D.
Sarlus, Zimer. "Geochemical and geochronological constraints on 1.88 and 1.80 Ga magmatic events in the Gällivare area, northern Sweden." Licentiate thesis, Luleå tekniska universitet, Geovetenskap och miljöteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-25689.
Повний текст джерелаThe Gällivare area is situated in northern Norrbotten, Sweden, and hosts the Aitik Cu-Au deposit and the Malmberget Fe deposit. In addition, more than 17 mineral prospects and mineralizations are present, among these the currently developed Nautanen Cu-Au deposit. All deposits are hosted within Paleoproterozoic volcanic and volcano-sedimentary successions intruded and surrounded by multiple generations of intrusive suites, including large bodies of ultramafic to mafic layered complexes. Detailed field mapping combined with geochemical and petrological investigations and geochronology have revealed the role of intrusive igneous events and their control on ore formation. Main key igneous rocks include 1) tholeiitic, ultramafic-mafic layered intrusive complexes; 2) calc-alkaline mafic to intermediate plutonic and volcanic units; 3) calc-alkaline, mafic-intermediate dykes and sills; 4) calc-alkaline and shoshonitic granitoids. U-Pb multigrain zircon SIMS analysis combined with litho-geochemical investigations suggest two magmatic episodes at 1.88 and 1.80 Ga, respectively, with coeval mafic-felsic magmatism including the generation of voluminous layered complexes. Based on their MORB-type, tholeiitic character, these layered complexes are suggested to have formed in an extensional setting, preferentially in a back-arc environment. U-Pb multigrain zircon SIMS analysis and field mapping also reveal that granitoids in the area range from 1886 to 1779 Ma with the oldest granitoids containing mafic enclaves. This suggests magma interaction between basic and felsic magma sources. Geochemical data suggest generation of granitoids in a volcanic arc environment in a mainly post-collisional setting. Results suggest the formation of layered complexes and a volcanic arc system in an extensional setting followed by a subsequent compressional phase of arc accretion producing post-collisional granitoids. The 1.88 Ga event that generated the ultramafic-mafic layered complexes is is associated with a back-arc setting generated in response to 1.90 Ga NNE trending subduction. The later event at ~1.80 Ga generating voluminous mafic-felsic units is associated with the TIB event also coupled to the regional IOCG overprint.
Godkänd; 2016; 20160518 (zimsar); Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Zmar Sarlus Ämne: Malmgeologi /Ore Geology Uppsats: Geochemical and Geochronological Constraints on 1.88 and 1.80 Ga Magmatic Events in the Gällivare Area, Northern Sweden Examinator: Biträdande professor Christina Wanhainen, Institutionen för samhällsbyggnad och naturresurser, Avdelning: Geovetenskap och miljöteknik, Luleå tekniska universitet. Diskutant: PhD Paul Evins, WSP Sverige AB, Stockholm. Tid: Fredag 17 juni, 2016 kl 10.00 Plats: F341, Luleå tekniska universitet
Hawkins, David Paul. "U-Pb geochronological constraints on the tectonic and thermal evolution of paleoproterozoic crust in the Grand Canyon, Arizona." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/10588.
Повний текст джерелаIncludes bibliographical references (p. 214-217).
by David Paul Hawkins.
Ph.D.
Makin, Sean W. "A Geochronological and Thermobarometric Investigation of Eclogites and overlying Hyllestad Schists from the Southern Western Gneiss Complex, Norway." Thesis, Curtin University, 2021. http://hdl.handle.net/20.500.11937/83006.
Повний текст джерелаBertrand, Audrey [Verfasser]. "Exhuming the core of collisional orogens, the Tauern Window, (Eastern-Alps) : A geochronological, modelling and structural study / Audrey Bertrand." Berlin : Freie Universität Berlin, 2014. http://d-nb.info/1047579405/34.
Повний текст джерелаBartz, Melanie [Verfasser], Helmut [Gutachter] Brückner, and Olaf [Gutachter] Bubenzer. "Quaternary fluvial environments in NE Morocco inferred from geochronological and sedimentological investigations / Melanie Bartz ; Gutachter: Helmut Brückner, Olaf Bubenzer." Köln : Universitäts- und Stadtbibliothek Köln, 2017. http://d-nb.info/1151298247/34.
Повний текст джерелаFriedrich, Anke Maria. "⁴⁰Ar/³⁹Ar and U-Pb geochronological constraints on the thermal and tectonic evolution of the Connemara Caledonides, Western Ireland." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/58264.
Повний текст джерелаIncludes bibliographical references.
The Connemara region of the Irish Caledonides is a classical example of a regional-scale high-temperature metamorphic terrain. Its formation was related to intrusion of a compressional continental magmatic arc, for which a protracted thermal evolution was inferred based on a >75 Ma spread in U-Pb, Rb-Sr, and K-Ar mineral dates. Such a history is inconsistent with field observations which suggest a simple relationship between metamorphism and syntectonic magmatism. This study was designed to explore the significance of the large spread in apparent ages using higher resolution U-Pb and 40Ar/ 39Ar geochronometers. The results indicate that arc magmatism, sillimanite-grade metamorphism, anatexis, and late fluid infiltration spanned only about 12 million years. Cooling following the metamorphic peak was actually relatively rapid at 35*C/Ma until about 460 Ma, then 214*C/Ma until 450 Ma. Regional differences in 40Ar/ 39Ar cooling ages of >15 Ma are related to spatial and temporal variations in magmatism, metamorphism, and deformation, rather than differential unroofing of the orogen. 40Ar/ 39Ar dates older than the onset of magmatism or younger than a regional Silurian unconformity represent the combined effects of excess 40Ar contamination, metasomatism, thermal resetting or alteration related to post-orogenic pluton emplacement. This study shows that geochronologic data must be evaluated in the context of careful field mapping, structural and petrologic analysis. Geochronological data from Connemara suggest that arc magmatism related to the Grampian orogeny in this region spanned a brief interval between 475 and 462 Ma and was followed by rapid cooling. The oldest recognized Grampian processes included high P/T metamorphism, followed by intrusion of the Connemara Gabbros into Dalradian metasedimentary rocks, regional-scale ductile deformation, and sillimanite-grade metamorphism between 474.5 and 470.1 Ma. Voluminous -467 Ma quartz diorites only intruded in southern Connemara associated with more localized deformation, anatexis and metasomatism between 468 and 462 Ma. Intrusion of the 462.5 Ma Oughterard Granite marks the end of arc magmatism and contractional deformation at Connemara. The compressional continental magmatic arc at Connemara (the Grampian orogeny) was coeval with continental arc magmatism in Scotland and Newfoundland, and postdates ophiolite formation and obduction along strike in the Appalachian- Caledonian orogen.
by Anke Maria Friedrich.
Ph.D.
Restrepo, Pedro Alonso. "Late Precambrian to Early Mesozoic tectonic evolution of the Colombian Andes, based on new geochronological geochemical and isotopic data." Diss., The University of Arizona, 1995. http://hdl.handle.net/10150/187450.
Повний текст джерелаMaguire, Henry C. "Application Of Geophysical And Geochronological Methods To Sedimentologic And Stratigraphic Problems In The Lower Cambrian Monkton Formation: Northwestern Vermont." ScholarWorks @ UVM, 2018. https://scholarworks.uvm.edu/graddis/938.
Повний текст джерелаTam, Evan. "Geochronological Constraints On The Timing Of Deformation: An Examination Of The Prospect Rock Fault Footwall In North-Central Vermont." ScholarWorks @ UVM, 2018. https://scholarworks.uvm.edu/graddis/940.
Повний текст джерелаAtkins, M. "A geochemical and geochronological study of U and Th radioisotopes in paleosols, loess and tephra : A Middle-Rhine case study." Thesis, University of Reading, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370805.
Повний текст джерелаAkciz, Sinan Osman 1974. "Structure and geochronological constraints on the ductile deformation observed along the Gaoligong Shan and Chong Shan Shear Zones, Yunnan (China)." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/30289.
Повний текст джерелаSome pages folded.
Includes bibliographical references.
The mechanism by which the Cenozoic post-collisional northward motion of India relative to Eurasia and South China was accommodated along its eastern boundary is still a poorly understood aspect of the tectonic evolution of SE Asia. This thesis focuses on a critically important area within the India-Eurasia collision zone, a region known as the Three Rivers area, and presents the first structural and geochronological data from several transects across two poorly documented linear metamorphic belts located in between the Sagaing fault and the Ailao Shan Shear Zone: the Gaoligong Shan Shear Zone (GSSZ) and the Chong Shan Shear Zone (CSSZ) in Yunnan, China. The presently inactive GSSZ is an important dextral Cenozoic (and possibly latest Mesozoic) ductile shear zone and appears to be the only right-lateral shear zone with the appropriate orientation to accommodate major pre- ca. 11 Ma northward movement of India relative to Eurasia. The previously unknown CSSZ is a long (>300 km) and wide (10- 20 km) metamorphic belt containing an assemblage low- to high-grade rocks from possibly several tectonic units which contain a prominent sub-vertical foliation and a sub-horizontal stretching lineation. Preliminary U/Pb results indicate that the ductile dextral shearing terminated by -18 Ma. Our regional map compilations indicate that the GSSZ and its proposed conjugate, the ASSZ, likely terminate within the Bangong Co-Nujiang suture zone.
(cont.) This thesis documents the dextral GSSZ as the conjugate pair to the sinistral ASSZ, and thus constrains the limits of the crustal fragments that extruded to the southeast. Based on our reinterpretations of the geological maps of Tibet and the Three Rivers area, however, we propose that the extruded crustal material originated east of the easternmost corner of the Indian indentor, and did not create space for the penetration of India;. while at least limited extrusion did occur, there is no compelling geological evidence to indicate large-scale eastward movement of crustal material from directly north of the India indentor. Data presented in this thesis also indicate that extruded region was dismembered into at least two major crustal fragments, separated by the CSSZ.
by Sinan Osman Akciz.
Ph.D.
Baldwin, Julia A. (Julia Ann) 1974. "Petrological and geochronological constraints on the metamorphic evolution of high-pressure granulites and eclogites of the Snowbird tectonic zone, Canada." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/30126.
Повний текст джерелаIncludes bibliographical references.
This thesis examines the petrology and geochronology of high-pressure granulites and eclogites within the Snowbird tectonic zone of the western Canadian Shield. The focus of this study is the East Athabasca mylonite triangle (EAmt), a well-exposed terrane of granulite facies mylonitic rocks along the trace of the Snowbird tectonic zone in northern Saskatchewan. This study focuses on the 400 km² Southern Domain of the EAmt, which contains a spectacular suite of high- pressure granulites and eclogites that have been metamorphosed at conditions exceeding 1.5 GPa and 1000⁰C. Each chapter of this thesis focuses on a different lithology within the Southern Domain - mafic granulite, eclogite, sapphirine granulite, and felsic granulite. The approach that is taken in understanding each of these rock types is an integrated study of the petrological and geochronological constraints that yield important information about the metamorphic evolution of these unique rocks. The main discovery through these integrated studies is that the Snowbird tectonic zone records a significant Paleoproterozoic high-pressure metamorphism that was previously unrecognized. Petrological and geochronological studies of each of these rock types constrains the pressure-temperature-time path of these rocks from their initial formation to their ultimate exhumation. The granulites and eclogites of the Southern Domain are derived from Archean igneous and sedimentary protoliths.
(cont.) The dominant rock type of the Southern Domain, the felsic gneiss, is interpreted to be derived from a pelitic protolith that underwent an early metamorphism at 2.62- 2.60 Ga. Protoliths of the mafic lithologies intruded at mid-crustal levels by 2.55-2.52 Ga. The eclogite protolith was derived from a plagioclase-bearing cumulate source at pressures <1.0 GPa. The eclogite and mafic granulite, and, to a lesser extent, the felsic gneiss record high-pressure metamorphism at 1.9 Ga. Near-isothermal decompression P-T paths in the mafic granulite and eclogite record rapid exhumation to medium-pressure granulite facies conditions of [approx.]1.0 GPa, 800⁰C. Sapphirine-bearing veins within the eclogite record further decompression, cooling, and re-equilibration in the middle crust at [approx.]0.6 GPa, 600-700⁰C. Final exhumation of these rocks occurred by more protracted erosional processes from 1.9 to 1.8 Ga.
by Julia A. Baldwin.
Ph.D.
Grant, Steven Lloyd. "Geochemical, radiogenic tracer isotopic, and U-Pb geochronological studies of Yukon Tanana terrane rocks from the Money klippe, southeastern Yukon, Canada." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq22600.pdf.
Повний текст джерелаSwain, Greg Martin. "Provenance and tectonics of the late Archaean mulgathing complex, central Gawler Craton : geochronological, geochemical and isotopic evidence for plume-arc interaction /." Title page, table of contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09SB/09sbs9715.pdf.
Повний текст джерелаFreeman, Hamish Stewart Rees. "A geochemical and isotopic study of mafic and intermediate rocks in the Oleary province, South Australia-Magma series discrimination and geochronological framework /." Title page, abstract and contents only, 1995. http://web4.library.adelaide.edu.au/theses/09SB/09sbf8553.pdf.
Повний текст джерелаSindern, Sven [Verfasser]. "Mineralogical, geochemical and geochronological studies in the Uralides and Variscides : contributions to the understanding of dynamic processes in collisional orogens / Sven Sindern." Aachen : Universitätsbibliothek der RWTH Aachen, 2014. http://d-nb.info/1133201571/34.
Повний текст джерелаOrdóñez, Casado Berta. "Geochronological studies of the pre-Mesozoic basement of the Iberian Massif : the Ossa Morena zone and the Allochthonous Complexes within the Central Iberian zone /." Zürich, 1998. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=12940.
Повний текст джерелаTseng, Chia-Han [Verfasser]. "The tablelands in the Puli Basin (central Taiwan) : a geochronological and geomorphological approach to Late Quaternary fluvial sedimentary and erosional processes / Chia-Han Tseng." Berlin : Freie Universität Berlin, 2014. http://d-nb.info/1052530834/34.
Повний текст джерелаEvuk, David [Verfasser], and Gerhard [Akademischer Betreuer] Franz. "Geodynamic evolution of the central-eastern Bayuda Desert Basement, Sudan : structural, petrological, geochemical and geochronological investigations / David Evuk. Gutachter: Gerhard Franz. Betreuer: Gerhard Franz." Berlin : Technische Universität Berlin, 2013. http://d-nb.info/1065665210/34.
Повний текст джерела