Dissertationen zum Thema „U-Pb dating on zircons“
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Hund, Erik A. „U-Pb dating of granites from the Charlotte belt of the southern Appalachians“. Thesis, Virginia Tech, 1987. http://hdl.handle.net/10919/45758.
Der volle Inhalt der QuelleMaster of Science
Sakata, Shuhei. „Development of analytical technique for precise age determination of Quaternary zircons with the correction of the initial disequilibrium on U-Th-Pb decay series using a laser ablation-ICP-mass spectrometry“. 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/199112.
Der volle Inhalt der QuelleEastwood, Alan Andrew. „The Tahorakuri Formation: Investigating the early evolution of the Taupo Volcanic Zone in buried volcanic rocks at Ngatamariki and Rotokawa geothermal fields“. Thesis, University of Canterbury. Geological Sciences, 2013. http://hdl.handle.net/10092/8925.
Der volle Inhalt der QuelleVoice, Peter James. „The Global Detrital Zircon Database: Quantifying the Timing and Rate of Crustal Growth“. Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/27785.
Der volle Inhalt der QuellePh. D.
Sanchez, Lohff Sonia K. „Upper plate response to varying subduction styles in the forearc Cook Inlet basin, south-central Alaska“. University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1530270586819066.
Der volle Inhalt der QuelleDilles, Zoe Y. G. „Geochronologic and Petrologic Context for Deep Crustal Metamorphic Core Complex Development, East Humboldt Range, Nevada“. Scholarship @ Claremont, 2016. http://scholarship.claremont.edu/scripps_theses/811.
Der volle Inhalt der QuelleMarsden, Ruby Connemara. „Further Development and Testing of the Combined U-Thdisequilibrium/ U-Pb and (U-Th)/He Zircon Dating Method and its Application to Quaternary Volcanic Rocks“. Thesis, Curtin University, 2021. http://hdl.handle.net/20.500.11937/88743.
Der volle Inhalt der QuelleGodon, Cécile. „L'érosion dans les environnements glaciaires : exemple du Glacier des Bossons (Massif du Mont-Blanc, Haute-Savoie, France)“. Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00909603.
Der volle Inhalt der QuelleBootes, Nathaniel R. „Late Cenozoic Offshore Record of Exhumation and Sediment Routing in Southeast Alaska from Detrital Zircon U/Pb and FT double-dating“. University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1592169111121451.
Der volle Inhalt der QuelleZacca, Patricia Luciana Aver. „40Ar-39Ar em overgrowths de feldspatos potássicos e U-Pb em zircão – aplicação conjunta para o entendimento da Formação Marizal - Bacia do Recôncavo“. reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/72084.
Der volle Inhalt der QuelleSandstones represent the most important reservoir rocks and aquifers in many sedimentary basins. It is necessary to have a precise chronostratigraphic position in order to provide a better explotation of water or hydrocarbons. Traditionally, the relative dating of sedimentary units is obtained with fossil content or stratigraphic correlation. But in many sedimentary rocks these analyses are not possible and sometimes have a dubious interpretation. This is the case of the Marizal Formation (Recôncavo Basin) where many questions arise when the age of the unit is questioned. The Marizal Formation is a fluvio-eolic sandstone which has been associated with an Albian/Aptian age in the stratigraphic column, although very discussible. Samples of sandstones of Marizal Formation present an important diagenetic overgrowths around K-feldspar detrital cores and they are suitable to 40Ar-39Ar dating concerning the identification of processes in the sandstones (as diagenesis or depositional ages). Among the heavy mineral suite in the Marizal Formation, zircon grains are identified. The U-Pb dating of detrital zircons can provide information about the provenance of the unit allowing better interpretation to the Marizal Formation. The overgrowths of K-feldspar indicated a value of 159.89 ± 23.96 Ma and to the detrital core, 432.57 ± 11.89 Ma. The mean value obtained around 160 Ma, considering that all care and analytical sample selection were considered, is older than expected. So, this was interpreted as indicating that the overgrowth, have been developed in a sedimentary source rock being transported latter to the depositional site. This age may be related to pre-rift stage of the Recôncavo Basin. The value confirms previous ideas of remobilization of the substrate during the rift basin stage. As has been extensively discussed, overgrowths of K-feldspars are stable and can be transported by small distances, which corroborates the above interpretation. The value obtained to the detrital core can be associated with a Paleoproterozoic sedimentary cover reworked in the Brazilian cycle. For zircon U-Pb dating, the data indicate no apparent Archean sources. The results show two main sources for sedimentation: a Rhyacian (Paleoproterozoic where ± 53% of the grains are "Transamazonian") and another Neoproterozoic-Cambrian (30% of zircon are "Brazilian").
Jones, Carson L. „U-Pb geochronology of monazite and zircon in Precambrian metamorphic rocks from the Ruby Range, SW Montana deciphering geological events that shaped the NW Wyoming province /“. [Kent, Ohio] : Kent State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=kent1214308001.
Der volle Inhalt der QuelleTitle from PDF t.p. (viewed Oct. 5, 2009). Advisor: Peter Dahl. Keywords: Geochronology; Radiometric Dating; Plate Tectonics. Includes bibliographical references (p. 106-109).
De, Assunção Rodrigues Mariana. „Analyse de la provenance sédimentaire des bassins du Crétacé du système Andes-Amazonie-marge équatoriale et des relations avec la paléogéographie et la tectonique“. Electronic Thesis or Diss., Toulouse 3, 2023. http://www.theses.fr/2023TOU30363.
Der volle Inhalt der QuelleThe Cretaceous is characterized by major paleogeographic, geodynamic, and climatic changes, including the formation of new oceans such as the equatorial Atlantic Ocean, the continued fragmentation of Gondwana, and greenhouse effect periods. All these changes are potentially contained in the sedimentary records of the basins. The Andes-Amazonia-Equatorial Margin system is a vast sedimentary system whose geodynamic and palaeoenvironmental evolution is recorded in the Amazonian retroarc foreland basins, the Brazilian intracratonic basins, and those of the equatorial margin. In the western part (Andean region), recent studies suggest that the onset of the Andean orogeny occurred during the Late Cretaceous, but the development of drainage systems and the source of sediments deposited during the Cretaceous are still poorly understood. The Lower Cretaceous is recorded in Brazilian intracratonic and equatorial basins and bears witness to crustal rifting phases following Gondwana's break-up. The Araripe Basin is a good example of these basins since it contains a complete and particularly well-studied sedimentary record. However, the origin of the sediments from the various tectonic stages of basin formation and the Cretaceous origin of the marine incursions that affected it remain to be determined. The aim of this thesis is to propose a palaeogeographic reconstruction of the Andes-Amazonia-Equatorial Margin system during the Cretaceous and to analyze the geodynamic and tectonic changes that affected it. To do this, we used provenance methods, in particular major and trace element geochemistry, Sm and Nd isotopic composition, and U-Pb ages on zircons. The results obtained have enabled us to identify the source zones of the Araripe Basin during the pre-, syn- and post-rift phases and thus to gain a better understanding of the palaeogeographic configuration of the north-eastern region of Brazil at the beginning of the Cretaceous. The sediments in the Araripe basin come mainly from the Palaeoproterozoic (2.3-1.6 Ga) terrains of the Borborema province and the granitic plutons of the Brasiliano cycle (720-541Ma). The basin has a sedimentary history linked to the South Atlantic and equatorial break-up phases. During the pre-rift phase (~152-135 Ma), the basin was part of the Afro-Brazilian depression and received sediments from the N-NW. During the rift phase (~135-125Ma), there was a change in source due to continental break-up and the formation of the South Atlantic, with an influx of sediments from the eastern part of the Borborema province. During the post-rift phase (121-113 Ma), the basin ceased to be fed by the eastern part and marine incursions dominated the sedimentation environment. Finally, during the post-rift II phase (113-100 Ma) a last change in sources was observed, with sources to the NE reflecting the final moment of the fragmentation of Gondwana. A study of the provenance of sediments from the basins of western Amazonia (Acre and Madre de Dios) indicates that the sources are cratonic, originating mainly from the Ventuari-Tapajos (2.0 - 1.82 Ga) and Rio Negro - Juruena (1.82 - 1.54 Ga) terrains. These results indicate that a vast intracontinental drainage network ('Sanozama') emerged in response to the uplift of the Purus Arch and the cratonic regions of Brazil and the Guianas during the opening of the equatorial Atlantic Ocean. The integration of the results obtained compiled with data from the literature has made it possible to propose four palaeogeographic maps of the northern part of the South American platform. They highlight how geodynamic mechanisms linked to the opening of the South Atlantic and equatorial oceans controlled and shaped the paleogeography of this region
Ng, Wai Pan. „Petrogenesis, U-Pb zircon geochronology and tectonic evolution of the Malaysian granite provinces in the Southeast Asian tin belt“. Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:0f2f3942-6d64-4a17-b194-08672107aeb2.
Der volle Inhalt der QuelleRoell, Jennifer L. „Geochemical evidence for incremental emplacement of Palms pluton, southern California“. Thesis, Connect to resource online, 2009. http://hdl.handle.net/1805/2061.
Der volle Inhalt der QuelleTitle from screen (viewed on February 2, 2010). Department of Earth Sciences, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Andrew P. Barth, Gabriel M. Filippelli, Kathy Licht. Includes vitae. Includes bibliographical references (leaves 102-110).
Brezina, Cynthia A. „The detrital mineral record of Cenozoic sedimentary rocks in the Central Burma Basin : implications for the evolution of the eastern Himalayan orogen and timing of large scale river capture“. Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/6730.
Der volle Inhalt der QuelleEly, Kim Susan. „Geochronology of Timor-Leste and seismo-tectonics of the southern Banda Arc“. Connect to thesis, 2009. http://repository.unimelb.edu.au/10187/7063.
Der volle Inhalt der QuelleU–Pb dating of detrital zircons from the Aileu Complex by LA-ICPMS show major age modes at 270–440 Ma, 860–1240 Ma and 1460–1870 Ma. The youngest zircon populations indicate a maximum depositional age of 270 Ma. The detrital zircon age populations and evidence for juvenile sediments within the sequence favours a synorogenic setting of deposition of sediments sourced from an East Malaya – Indochina terrane.
Previous uncertainty in aspects of the cooling history for the Aileu Complex is resolved with 39Ar/40Ar geochronology of hornblende. Cooling ages of 6–10 Ma are established, with the highest metamorphic grade parts of the Complex yielding the older ages. Cooling ages of 10 Ma imply that metamorphism of the Aileu Complex must have commenced by at least ~12 Ma. Metamorphism at this time is attributed to an arc setting rather than the direct result of collision of the Australian continent with the Banda Arc, an interpretation consistent with the new provenance data.
Geological mapping of Ataúro, an island in the volcanic Banda Arc north of Timor, reveals a volcanic history of bi-modal subaqueous volcanism. 39Ar/40Ar geochronology of hornblende from dacitic lavas confirms that volcanism ceased by ~3 Ma. Following the cessation of volcanism, coral reef marine terraces have been uplifted to elevations of 700 m above sea level. Continuity of the terraces at constant elevations around the island reflects regional-scale uplift most likely linked to sublithospheric processes such as slab detachment.
North of Timor, the near complete absence of intermediate depth seismicity beneath the inactive segment of the arc is attributed to a slab window that has opened in the collision zone and extends to 350 km below the surface. Differences in seismic moment release around this slab window indicate asymmetric rupture, propagating to the east at a much faster rate than to the west. If the lower boundary of this seismic gap signifies the original slab rupture then the slab window represents ~4 m.y. of subsequent subduction and implies that collision preceded the end of volcanism by at least 1 m.y.
Variations in seismic moment release and stress state across the transition from subduction of oceanic crust to arc–continent collision in the Banda Arc are investigated using earthquake catalogues. It is shown that the slab under the western Savu Sea is unusual in that intermediate depth (70–300 km) events indicate that the slab is largely in down-dip compression at this depth range, beneath a region of the arc that has the closest spacing of volcanoes in the Sunda–Banda arc system. This unusual state of stress is attributed to subduction of a northern extension of the Scott Plateau. Present day deformation in the Savu Sea region may be analogous with the earliest stages of collision north of Timor.
Ternois, Sébastien. „Reconstruction de la Dynamique Précoce d'un Orogène : Mise en évidence de la Transition Rifting-Collision dans le système est-pyrénéen (France) par la Géo-thermochronologie“. Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0086/document.
Der volle Inhalt der QuelleCollisional orogens are classically described as the result of continental accretion of proximal margins. This accretion leads to the creation of relief and to the important export of erosion products in the directly adjacent foreland basins. In this geodynamic scheme, only the least deformed pre-orogenic domains are considered. However, a growing number of geological field evidences indicate the preservation or even the reuse of structures inherited from the rifting phase preceding convergence and collision within orogens. By conducting a geo-thermochronometric study of the easternmost, inverted hyperextended Aptian-Cenomanian rift system (Agly massif, North Pyrenean Zone) and the adjacent early retroforeland (Rennes-les-Bains syncline, Aquitaine Basin), this thesis aims to describe the evolution of a distal rifted margin during the first stages of convergence, to quantify the associated source-to-sink processes and to provide temporal and paleogeographic constraints regarding the creation of the very first Pyrenean reliefs resulting from inversion of the margin. Using the zircon and apatite (U-Th)/He multi-thermochronometers, I show that the Pyrenean retro-wedge records two clear phases of orogenic cooling, Late Campanian-Maastrichtian and Ypresian-Bartonian, which I relate to early inversion of the distal rifted margin and main collision, respectively. I have thus been able to propose a crustal-scale sequentially restored model for the tectonic and thermal transition from extension to peak orogenesis in the eastern Pyrenees, which suggests that both thrusting and underplating processes contributed to early inversion of the Aptian-Cenomanian rift system. The absence of Paleocene cooling record indicates little to no erosion of the Pyrenean retro-wedge, suggesting the existence of a more easterly source area supplying early retroforeland sediments at this time. To characterize this eastern edifice, which has since been destroyed by the Oligocene-Miocene opening of the Gulf of Lion, I used in situ (U-Th)/He - U/Pb double dating on detrital zircons and show rapid denudation rates during early convergence, characteristic of early topographic growth. This work shows for the first time clearly the progressive migration of deformation from east to west by inversion of inherited structures at the beginning of Pyrenean convergence. This suggests the existence of an open domain in the east at the end of the rifting phase preceding convergence. This study highlights the role of the architecture of hyper-thinned systems in the formation of collisional orogens and confirms the close links between an orogen and its foreland basins
Guerrot, Catherine. „Archéen et ProtérozoÏque dans la chaîne hercynienne ouest-européenne : géochimie isotopique (Sr-Nd-Pb) et géochronologie U-Pb sur zircons“. Phd thesis, Université Rennes 1, 1989. http://tel.archives-ouvertes.fr/tel-00653455.
Der volle Inhalt der QuelleGuerrot, Catherine. „Archéen et Protérozoïque dans la chaîne hercynienne Ouest-européenne : géochimie isotopique Sr-Nd-Pb et géochronologie U-Pb sur zircons /“. Rennes : Centre Armoricain d'étude structurale des socles, 1989. http://catalogue.bnf.fr/ark:/12148/cb35048785z.
Der volle Inhalt der QuelleSorota, Kristin Joy. „Age and Origin of the Merrimack Terrane, Southeastern New England: A Detrital Zircon U-Pb Geochronology Study“. Thesis, Boston College, 2013. http://hdl.handle.net/2345/3043.
Der volle Inhalt der QuelleThesis advisor: Yvette D. Kuiper
Metasedimentary rocks of the Merrimack terrane (MT) originated as a thick cover sequence on Ganderia consisting of sandstones, calcareous sandstones, pelitic rocks and turbidites. In order to investigate the age, provenance and stratigraphic order of these rocks and correlations with adjoining terranes, detrital zircon suites from 7 formations across the MT along a NNE-trending transect from east-central Massachusetts to SE New Hampshire were analyzed by U-Pb LA-ICP-MS methods on 90-140 grains per sample. The youngest detrital zircons in the western units, the Worcester, Oakdale and Paxton Formations, are ca. 438 Ma while those in the Kittery, Eliot and Berwick Formations in the northeast are ca. 426 Ma. The Tower Hill Formation previously interpreted to form the easternmost unit of the MT in MA, has a distinctly different zircon distribution with its youngest zircon population in the Cambrian. All samples except for the Tower Hill Formation have detrital zircon age distributions with significant peaks in the mid-to late Ordovician, similar abundances of early Paleozoic and late Neoproterozoic zircons, significant input from ~1.0 to ~1.8 Ga sources and limited Archean grains. The similarities in zircon provenance suggest that all units across the terrane, except for the Tower Hill Formation, belong to a single sequence of rocks, with similar sources and with the units in the NE possibly being somewhat younger than those in east-central Massachusetts. The continuous zircon age distributions observed throughout the Mesoproterozoic and late Paleoproterozoic are consistent with an Amazonian source. All samples, except the Tower Hill Formation, show sedimentary input from both Ganderian and Laurentian sources and suggest that Laurentian input increases as the maximum depositional age decreases
Thesis (MS) — Boston College, 2013
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Geology and Geophysics
Martin, Laure. „Signification des âges U-Pb sur zircon dans l'histoire métamorphique de Naxos et Ikaria (Cyclades, Grèce)“. Nancy 1, 2004. http://www.theses.fr/2004NAN10231.
Der volle Inhalt der QuelleThe knowledge of pressure - temperature - time paths in metamorphic rocks is necessary to the understanding of orogenic belts evolution. U-Pb method is commonly used for dating metamorphic events, but the link between metamorphic conditions and ages obtained on zircon is not straightforward. Oxygen isotopes are proposed in this study for likening zircon to garnet growth in metamorphic rocks of the Aegean domain. The study of four samples from Naxos island showed that this correlation is possible if (i) isotopic equilibrium of oxygen is reached between garnet and zircon during their formation and (ii) garnet and zircon remained in closed system for oxygen and lead after their formation. This method permitted to date the beginning of the exhumation of metamorphic rocks from Naxos between 40 and 60 Ma, and the beginning of the retrograde path between 13 and 19 Ma. The preferential formation of zircon between 40 and 60 Ma in rocks localised in schist rich zones indicate that pressure and fluid circulation are the parameters that triggered zircon formation during the metamorphism
Stangroom, Amber M. „High-precision U/Pb dating of the Cenomanian-Turonian boundary Kaiparowits Plateau, Utah“. Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/114340.
Der volle Inhalt der QuelleCataloged from PDF version of thesis.
Includes bibliographical references (pages 33-40).
The massive marine species turnover at the Cenomanian-Turonian boundary is associated with Oceanic Anoxic Event 11 (OAE II) and is often identified by an increase of a13C in the carbon isotopic record. A high-precision chronology of the Cenomanian- Turonian boundary is needed to better constrain the cause, timing, and extent of OAE II. To create such a timeline, four bentonite samples from the Kaiparowits Plateau, Utah were dated using U/Pb geochronology. The Cenomanian-Turonian boundary is constrained to be 94.040 ± 0.029/0.098/0.14 Ma, in agreement with recent astrochronologic studies of the same time period. This research will help improve the calibration of the astronomical time scale, as well as provide a greater understanding of the Cretaceous environment..
by Amber M. Stangroom.
S.B.
Montano, Damaris. „Carbonate U-Pb dating via LA-ICPMS : insights into chronostratigraphy in lacustrine settings“. Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS545.
Der volle Inhalt der QuelleLacustrine deposits are extensively investigated because they play a pivotal role as environmental recorders and host valuable economic resources. However, chronostratigraphic reconstructions in these settings are usually hampered by the scarcity of data required to establish the depositional age of the system. The prime objective of this PhD project was examining benefits and limitations of carbonate U-Pb (LA-ICPMS) dating (LAcarb) as new chronostratigraphic tool for lacustrine deposits. The second objective was to investigate the dating potential, in terms of dating success and time resolution, of various carbonate types and mineralogies with the aim to better organize future LAcarb based research. To achieve these goals, depositional (microbialites, ooids, oncoids) and early diagenetic carbonate phases of known absolute age were collected from two lacustrine settings: the Ries Crater basin (Miocene, SW Germany) and the Yacoraite formation (Fm.) from the Salta rift basin (Cretaceous-Paleogene, NW Argentina). A sedimentologic and diagenetic study based on petrography and Oxygen (O) and Carbon (C) stable isotope analysis allowed to select carbonate phases that most possibly preserved the pristine U-Pb geochemical composition and consequently inform on the timing of deposition. In the Ries Crater basin, LAcarb provided accurate ages that allowed chronostratigraphic correlations at a time resolution of the 3rd order stratigraphic sequence (0.5–5Ma). In the framework of the Yacoraite Fm., two depositional age depth model were obtained along a stratigraphic section. One derived from zircon (ash layer) geochronology (maximum depositional age depth model; MDA depth model) and the other from LAcarb (minimum depositional age depth model; MIDA depth model). The two models remarkably overlap and describe the same sedimentation rate dynamic with a time resolution between 0.9 and 2% (2σ). The revised depositional age of the Yacoraite Fm. was then integrated in a chronostratigraphic model merging biostratigraphic, chemostratigraphy and magnetostratigraphy data from literature. Accordingly, the KPg limit was interpreted to be located in the Yacoraite Fm. whereas the two Paleocene-Eocene hyperthermals (Paleocene-Eocene Thermal Maximum, PETM; early Eocene Climate Optimum, EECO) were identified in the two overlying formations. A statistical analysis was achieved based on the ages of 80 carbonate phases from the Yacoraite Fm. Microbialites provided the lowest dating success (41% ages consistent with the MDA depth model) and age precision (2σ < 10%) in contrast with lacustrine cements that yielded the highest dating success (64% ages consistent with MDA depth model) and age precision (2σ < 3%). Furthermore, calcitic phases usually provided more precise ages than dolomitic phases. The better comprehension of potentialities and limitations of LAcarb acquired in this PhD allowed to propose a workflow to build a robust depositional age depth model in lacustrine settings. Three possible perspective scenarios were introduced: 1) the study of the Ries Crater basin as analogue of paleolakes on Mars; 2) the use of LAcarb to select pristine carbonates for chronostratigraphic studies; and 3) basin scale chronostratigraphic correlations in the Yacoraite Fm
Loehn, Clayton William. „Investigation of the monazite chemical dating technique“. Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/27688.
Der volle Inhalt der QuellePh. D.
Guenthner, William Rexford. „Zircon (U-Th)/He Dates from Radiation Damaged Crystals: A New Damage-He Diffusivity Model for the Zircon (U-Th)/He Thermochronometer“. Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/306783.
Der volle Inhalt der QuelleSimons, Suzanne Lee. „U-Th-Pb systematics of opaline silica: Implications for the dating of surface processes“. Thesis, Curtin University, 2015. http://hdl.handle.net/20.500.11937/36.
Der volle Inhalt der QuellePepper, Martin Bailey. „Magmatic History and Crustal Genesis of South America: Constraints from U-Pb Ages and Hf Isotopes of Detrital Zircons in Modern Rivers“. Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/347220.
Der volle Inhalt der QuelleDada, Silas Sunday. „Évolution de la croûte continentale au nord Nigeria : apport de la géochimie, de la géochronologie U-Pb et des traceurs isotopiques Sr, Nd et Pb“. Montpellier 2, 1989. http://www.theses.fr/1989MON20153.
Der volle Inhalt der QuelleAllégret, André. „Contribution à la connaissance de l'évolution géodynamique anté-varisque de la croûte continentale de la Péninsule ibérique par la géochronologie U/Pb sur zircons“. Montpellier 2, 1989. http://www.theses.fr/1989MON20196.
Der volle Inhalt der QuelleTernois, Sébastien. „Reconstruction de la Dynamique Précoce d'un Orogène : Mise en évidence de la Transition Rifting-Collision dans le système est-pyrénéen (France) par la Géo-thermochronologie“. Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0086.
Der volle Inhalt der QuelleCollisional orogens are classically described as the result of continental accretion of proximal margins. This accretion leads to the creation of relief and to the important export of erosion products in the directly adjacent foreland basins. In this geodynamic scheme, only the least deformed pre-orogenic domains are considered. However, a growing number of geological field evidences indicate the preservation or even the reuse of structures inherited from the rifting phase preceding convergence and collision within orogens. By conducting a geo-thermochronometric study of the easternmost, inverted hyperextended Aptian-Cenomanian rift system (Agly massif, North Pyrenean Zone) and the adjacent early retroforeland (Rennes-les-Bains syncline, Aquitaine Basin), this thesis aims to describe the evolution of a distal rifted margin during the first stages of convergence, to quantify the associated source-to-sink processes and to provide temporal and paleogeographic constraints regarding the creation of the very first Pyrenean reliefs resulting from inversion of the margin. Using the zircon and apatite (U-Th)/He multi-thermochronometers, I show that the Pyrenean retro-wedge records two clear phases of orogenic cooling, Late Campanian-Maastrichtian and Ypresian-Bartonian, which I relate to early inversion of the distal rifted margin and main collision, respectively. I have thus been able to propose a crustal-scale sequentially restored model for the tectonic and thermal transition from extension to peak orogenesis in the eastern Pyrenees, which suggests that both thrusting and underplating processes contributed to early inversion of the Aptian-Cenomanian rift system. The absence of Paleocene cooling record indicates little to no erosion of the Pyrenean retro-wedge, suggesting the existence of a more easterly source area supplying early retroforeland sediments at this time. To characterize this eastern edifice, which has since been destroyed by the Oligocene-Miocene opening of the Gulf of Lion, I used in situ (U-Th)/He - U/Pb double dating on detrital zircons and show rapid denudation rates during early convergence, characteristic of early topographic growth. This work shows for the first time clearly the progressive migration of deformation from east to west by inversion of inherited structures at the beginning of Pyrenean convergence. This suggests the existence of an open domain in the east at the end of the rifting phase preceding convergence. This study highlights the role of the architecture of hyper-thinned systems in the formation of collisional orogens and confirms the close links between an orogen and its foreland basins
Melleton, Jérémie. „Modalités du recyclage de la croûte continentale dans l'orogène varisque par traçage in situ des zircons hérités (mesures U -Pb/LA-MC-ICPMS)“. Phd thesis, Université d'Orléans, 2008. http://tel.archives-ouvertes.fr/tel-00388706.
Der volle Inhalt der QuelleLuo, Yan, und 羅彥. „U-Pb age and Hf isotopic study of detrital zircons from the Liaohe Group: constraints on the evolution of theJiao-Liao-Ji Belt, North China craton“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B36639242.
Der volle Inhalt der QuelleLIMONCELLI, MARTA. „Short-term erosion pattern in the Alps-Apennines belt constrained by downstream changes of zircons morphology and U-PB ages from the Po drainage modern sands“. Doctoral thesis, Università degli Studi di Milano-Bicocca, 2012. http://hdl.handle.net/10281/29393.
Der volle Inhalt der QuelleReid, Mattie Morgan. „Forearc basin detrital zircon provenance of Mesozoic terrane accretion and translation, Talkeetna Mountains-Matanuska Valley, south-central Alaska“. Thesis, University of Iowa, 2017. https://ir.uiowa.edu/etd/5611.
Der volle Inhalt der QuelleAndersson, Barbro. „Metamorphic Evolution of the Tjeliken Garnet-Phengite Gneiss, Northern Jämtland, Swedish Caledonides“. Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-276515.
Der volle Inhalt der QuelleDen skandinaviska fjällkedjan, vetenskapligt benämnd de skandinaviska Kaledoniderna, har bildats på samma sätt som Himalaya och har därför liknande uppbyggnad. Från början tros fjällen ha varit av samma storlek som Himalayas berg. Deras ålder på cirka 400 miljoner år gör dock att miljontals års påverkan från vatten och vind har eroderat ner dem till dagens betydligt lägre fjäll. Den bergsyta vi ser idag utgör därför vad som från början var fjällkedjans kärna. Därför utgör de skandinaviska Kaledoniderna en unik möjlighet att studera en bergskedjas inre, vilket kan ge viktig information om bergkedjebildande processer.Forskning har visat att fjällkedjan bildades då Japetushavet mellan kontinenterna Baltika och Laurentia stängdes. Detta resulterade till slut i en kollision mellan de två kontinenterna där stora flak (skollor) av mellanliggande havsbotten och kontinentalskorpa transporterades hundratals kilometer upp på Baltika. Skollorna utgör idag våra fjäll. Känt är också att innan kontinentalkollisionen så kolliderade Baltika med öar i havet, varvid dess kontinentalkant pressades djupt ner under jordskorpan, ända ner i manteln. Bevis för detta återfinns idag i Sevesskollan ibland annat de jämtländska fjällen i form av högtrycksbergarter. Dessa har bildats under de höga tryck och temperaturer som råder på stora djup i jordens inre. Genom att studera högtrycksbergarter kan man förstå fjällkedjans bildande. Fjället Tjeliken i norra Jämtland är en av de idag kända fyndplatserna av högtrycksbergarter. Dess topp består av bergarten eklogit och dess lägre delar av gnejs, samt kvarts. Tidigare studier av eklogiten visar att den har bildats vid tryck och temperatur på cirka 2.6 GPa och 700 °C, vilket motsvarar att den varit nedpressad cirka 80 km under jordytan. Den exakta tidpunkten då detta skedde har inte kunnat fastställas då olika dateringsmetoder gett olika resultat mellan cirka 464 till 446 miljoner år sedan. I denna studie studeras tryck- och temperaturförhållanden för gnejsen som jämförelse till eklogiten, för att kunna fastställa om de båda bergarterna har genomgått samma bildningsprocesser. En ny datering genomförs också för att bättre kunna fastställa tidpunkten för högtrycksfasen.Datering baserat på radioaktivt sönderfall av uran till bly i mineralet zirkon visar att högtrycksfasen inträffade för cirka 460 miljoner år sedan. Modellering baserat på termodynamiska principer visar att kärnorna i mineralet granat bildades inom tryck- och temperaturområdet 1.9–2.6 GPa och c. 680-700 °C. En komplex kemisk zonering av granaterna indikerar att de möjligen bildades under flera tillväxtfaser, vilka inom ramen för denna studie inte kunnat modelleras, då mer avancerade metoder krävs. Denna studie visar dock att eklogiten och gnejsen sannolikt delar en gemensam tryck- och temperaturhistoria, vilken är relaterad till den djupa nedpressningen av Baltikas kontinentalkant under sen ordovicium. Dateringen stödjer även övriga åldersdateringar i området av högtrycksfasen.
Luo, Yan. „U-Pb age and Hf isotopic study of detrital zircons from the Liaohe Group constraints on the evolution of the Jiao-Liao-Ji Belt, North China craton /“. Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B36639242.
Der volle Inhalt der QuelleKawata, Marcelo Takei. „Evolução tectono-metamórfica da formação São Tomé, Grupo Rio Doce, faixa Araçuaí“. Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/44/44141/tde-17072018-144805/.
Der volle Inhalt der QuelleThe present dissertation presents an investigation on the tectono-metamorphic evolution of the São Tomé Formation, one of the metasedimentary units belonging to the Rio Doce Group, in the Araçuaí Orogen. This unit, of pelitic origin, occurs in a band with general direction approximately N-S, with vergence for NE, contrary to the São Francisco craton in this sector of the orogen. It has quartz-mica schist as main lithotype, with varying proportions of grarnet, staurolite, sillimanite and plagioclase. Two deformational phases are recorded through a continuous foliation S1 of the fracture cleavage type and a foliation S2 of crenulation cleavage. The textural relations indicate that part of the mineral phases crystallized both during the deformational event and in conditions absent of deviatore voltage, and record of metamorphic peak conditions of 6 kbar and 650 ° C. The geochronological data were obtained in monazite by means of Th-U-Pb dating in electron microprobe. Three distinct populations were identified: (i) The oldest population of 641 ± 32 Ma, 614 ± 39 Ma and 607 ± 47 Ma, which may represent detrital grains of igneous bodies, no longer outcrops, related to a possible pre- collisional or, being metamorphic monazites formed in a first thermal event; (ii) Populations with intermediate ages between 560 ± 32 Ma and 559 ± 29 Ma, compatible with regional metamorphic apex ages; (iii) Younger population between 501 ± 28 Ma and 491 ± 34 Ma, consistent with the formation concomitant with the generation of late igneous bodies. Although it is unclear whether these ages are related to distinct metamorphic events or are reflective of the low orogenic cooling rate, the three monazite groups of different ages are well established.
Wenham, Lana May. „Putting absolute, in-situ U-Pb ages to early-Archaean deformation events in the Muccan Granitic Complex, East Pilbara Terrane“. Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/120829/2/Lana_Wenham_Thesis.pdf.
Der volle Inhalt der QuelleDe, Joux Alexandra. „Cosmos greenstone terrane : insights into an Archaean volcanic arc, associated with komatiite-hosted nickel sulphide mineralisation, from U-Pb dating, volcanic stratigraphy and geochemistry“. Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/8918.
Der volle Inhalt der QuelleGaylor, Jonathan. „40Ar/39Ar Dating of the Late Cretaceous“. Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-01017165.
Der volle Inhalt der QuellePAVANETTO, PAMELA. „Zircon U-PB and LU-HF isotopic data from some peri-gondwana variscan terranes (Sardinia-Corsica block and calabropeloritan arc): new insights on the cenozoic geodynamic evolution of the central mediterranean basin“. Doctoral thesis, Università degli Studi di Cagliari, 2012. http://hdl.handle.net/11584/266140.
Der volle Inhalt der QuelleBruguier, Olivier. „Applications de la géochronologie U-Pb sur monocristal de zircon abrasé en domaines sédimentaire et magmatique : source des matériaux détritiques, témoins archéens crustaux et géodynamique globale“. Montpellier 2, 1993. http://www.theses.fr/1993MON20106.
Der volle Inhalt der QuelleCannic, Sébastien. „L'évolution magmatique et tectono-métamorphique du substratum du domaine valaisan (complexe du Versoyen, Alpes occidentales) : Implications dans l'histoire alpine“. Grenoble 1, 1996. http://www.theses.fr/1996GRE10155.
Der volle Inhalt der QuelleDidier, Amélie. „Comportement géochimique du chronomètre U-Th-Pb dans la monazite : approche par analyses in-situ au LA-ICP-MS“. Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2013. http://tel.archives-ouvertes.fr/tel-00966588.
Der volle Inhalt der QuelleAiraghi, Laura. „Etude pétro-chronologique de la chaîne des Longmen Shan (Tibet oriental) : héritage géologique et implications pour la géodynamique actuelle“. Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAU029/document.
Der volle Inhalt der QuelleOne of the major challenges in Earth Sciences is understanding how the continental lithosphere deforms in convergent settings, according to which timescales. For its elevation and extension the Tibetan plateau is an ideal natural laboratory for the study of deep crustal processes in active convergent settings. The rise and thickening of the Tibetan plateau has generally been related to the only collision between the Eurasian and Indian plates during the Cenozoic. However, this interpretation has been recently put into question by apparently contrasting geophysical and geological features observed at different locations on the plateau.The aim of this PhD is to quantify the importance of the geological inheritance in the long-term and short-term deformation of an active thrust belt, focusing on the Longmen Shan orogen, the most enigmatic border of the Tibetan plateau. In the Longmen Shan (eastern Tibet) the Tibetan crust is over thickened (>60 km), the tectonic activity is localized along lithospheric faults -as demonstrated by the occurrence of the Mw 7.9 Wenchuan (2008) and Mw 6.6 Lushan (2013) earthquakes- and a high topography survives despite low convergence rates measured by GPS (<3 mm/yr). These observations are hardly reconcilable in a unique model of crustal deformation, suggesting a contribution of the geological inheritance from the geological history preceding the India-Asia collision.A petro-chronological approach that combines microstructural observations, compositional mapping of major and accessory mineral phases, thermodynamic modelling, in-situ 40Ar/39Ar dating, Ar diffusion modelling and in-situ U/Pb-Th allanite dating was applied to metamorphic rocks on each side of the major faults that strike parallel to the belt. This high-resolution study shows that in garnet-bearing rocks of the internal units of the belt matrix minerals record different stages of the metamorphic path in their composition. This is due to an incomplete chemical re-equilibration explained by a variable fluid availability during metamorphism. Different stages of metamorphism and fluid-assisted reactions sequences are also recorded in the 40Ar/39Ar signal of micas and in the composition and textures of the accessory phases.The understanding of petrological processes at the small scale was combined with field observations to quantify the Mesozoic thickness of the Tibetan crust at > 30 km and to unravel a metamorphic jump of greater than 150°C across the major faults, inherited from the Mesozoic tectonics. While internal units of the belt were strongly deformed, decoupled from the basement and metamorphosed at T ~ 580-600°C (P ~11 kbar), external units were less deformed and experienced lower temperatures conditions (T < 400°C, P < 5 kbar). The partial exhumation of the crystalline basement from c. 20 km depth along the major fault (in both internal and external units) occurred at c. 120-140 Ma during a previously poorly documented tectonic event.The multi-method approach applied on a wide geographical area and on a large time interval enabled to quantify the rates and conditions of the different stages of the maturation of the belt; internal units reached the thermal relaxation at ~600°C 40 Ma after the beginning of the propagation of the orogenic load. The basement was re-activated 40 Ma later, at similar thermal conditions than its sedimentary cover. The Mesozoic geological inheritance is therefore a key element in the present structure of the belt and strongly controlled the rheological and structural state of the upper crust at the moment of the Cenozoic re-activation.The petro-chronological study of different segments of the belt showed an along-strike metamorphic segmentation of the Longmen Shan inherited from the Mesozoic. This segmentation corresponds to the present fault segmentation, underlying the potential role of inherited structure in controlling the geographic distribution of the recent earthquakes
Laurent, Antonin. „Etude pétrologique et chronométrique (U-Th-Pb) de la monazite et du zircon dans les granulites de ultra-haute température du Rogaland, Norvège“. Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30290/document.
Der volle Inhalt der QuelleUnderstanding mountain building processes requires a better integration of petrological and peochronological data in order to link pressure-temperature paths to absolute ages. This work focuses on the behaviour of monazite and zircon, which are used as geochronometers, in ultra-high temperature granulites of Rogaland (South Norway). We show that linking in-situ U-Th-Pb dating of monazite with its major- and trace-element composition lead to the recognition of two ultra-high temperature (UHT) metamorphic events in Rogaland at c.1030-1005 Ma and c. 940-930 Ma. Indeed, the examination of monazite-xenotime-huttonite phase relationships suggests that monazite may record crystallization age at or near ultra-high temperature. Besides, the chemical and U-Th-Pb-O isotopic characterization of zircon neo-crystallization or overgrowths indicates that the Rogaland crust remains molten (> 800 °C at 0.7-0.4 GPa) at least during 60 My between the two identified UHT excursions. This manuscript also highlights the various factors responsible for U-Th-Pb (partial) resetting in the course of granulite facies metamorphism. Zircon behaviour is mostly controlled its level of amorphization, enhancing Pb loss during annealing, whereas monazite resetting is dominated by dissolution-precipitation processes in the presence of a melt or fluid phase. More specifically, we point out that monazite may be used to monitor the redox conditions of its crystallizing medium since monazite may incorporate the redox-sensitive element S in its lattice as sulphate. Finally, we demonstrate a spatial and temporal correlation between magmatism and UHT metamorphism in Rogaland. The timescale, P-T path and tectono-magmatic history however cannot be explained by currently accepted models for UHT. We suggest that physical and thermal specificities of Proterozoic mantle may explain the observed ultra-hot orogen style and the occurrence of gravity driven processes during orogeny
Moussavou, Mathieu. „Contribution à l'histoire thermo-tectonique varisque du massif des Maures, par la typologie du zircon et la géochronologie U/Pb sur minéraux accessoires (Var, France)“. Montpellier 2, 1998. http://www.theses.fr/1998MON20016.
Der volle Inhalt der QuelleGauthiez, Putallaz Laure. „Tracing fluids during medium to ultra-high pressure metamorphism: insights by combined in situ oxygen isotopes and trace element analysis“. Phd thesis, Canberra, ACT : The Australian National University, 2017. http://hdl.handle.net/1885/157028.
Der volle Inhalt der QuelleGreen, Michael Godfrey. „Early Archaean crustal evolution: evidence from ~3.5million year old greenstone successions in the Pilgangoora Belt, Pilbara Craton, Australia“. University of Sydney. Geosciences, 2001. http://hdl.handle.net/2123/505.
Der volle Inhalt der QuelleKahou, Steven. „Caractérisation pétro-géochimique des minéralisations cuprifères supergènes en Atacama (Nord Chili) : potentiel chronométrique U-Pb et conditions de formation“. Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30285.
Der volle Inhalt der QuelleSupergene copper mineralization (SCM) are nowadays the economic viability of many porphyry copper deposits worldwide. These mineralization are derived from supergene processes, defined as sulfide oxidation and leaching of ore deposits in the weathering environment, and any attendant secondary sulfide enrichment. For supergene copper mineralization to form, favorable tectonics, climate and geomorphologic conditions are required. Tectonics control the uplift needed to induce groundwater lowering and leaching of sulphides from a porphyry copper deposit. Climate controls copper leaching in the supergene environment and groundwater circulation towards the locus where supergene copper-bearing minerals precipitate. In Atacama Desert of northern Chile, SCM seem to take place during specific Tertiary climatic periods and relief formation. But many uncertainties remain regarding the genesis and the exact timing for SCM formation. We present mineralogical and chemical data on supergene copper-bearing minerals sampled from in situ and exotic SCM from two geologically and climatically distinct areas, namely the Atacama Desert of northern Chile and the Gaoua porphyry Cu-Au district in Burkina Faso. Although both areas have experienced different geological conditions, they both underwent similar geological and climatic controls to form and preserve SCM. Chrysocolla and pseudomalachite are the most common copper-bearing minerals found in SCM from the Atacama Desert of northern Chile. This led us to test the potential of both minerals as dating materials to place the SCM formation in a geochronological context. However, variation of U content from one mineral to another, common Pb contribution and the absence of matrix-matched-standard for both minerals made U-Pb LA-ICP-MS dating of chrysocolla and pseudomalachite challenging. A mixed approach combining texturally-controlled in situ LA-ICP-MS U-Pb dating and multi-elements mapping together with SIMS oxygen isotope analyses were applied to Mina Sur, Damiana and El Cobre exotic copper deposits and the in situ SCM of the Gaoua porphyry Cu-Au district. Regardless their location, the results demonstrate the important role played by the local geological parameters on the control of the U-Pb chronometer in supergene copper minerals. Initial high U content of the porphyry source can promote U-rich supergene copper minerals as it is the case at Mina Sur. Additionally, a long-term supergene alteration will favor long term water circulation in the depositional environment which can leached U from the porphyry source and allow the formation of U-low supergene copper minerals during recent times. The promising results obtained represent a new tool to understand the physico-chemical, climatic and geological conditions that prevailed during the formation of supergene copper deposits and a proxy for their prospection around the world