Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 20 for “"exhumation rates"”.
-
The Impact of Long-Term Glacial Erosion on the Active Chugach-St. Elias Mountains, southern Alaska
… there to limit topographic development. Exhumation would therefore be expected to increase towards the coast. If glacial erosion is not dominant, exhumation would be expected to increase away from the coast towards the core of the range, where fault dip angles are high and deep crustal …
-
Post-Orogenic Exhumation and Glacial Erosion on the Flanks of the North Atlantic
Many passive margins experience pulsed exhumation events late in their history as a result of plate boundary distal geodynamic mechanisms or climatic events. The onset of late Cenozoic glaciation, often associated with enhanced rates of erosion, is one such possible cause of passive margin …
-
Late Cenozoic Exhumation in a Transpressional Setting: Fairweather Range, Alaska
… (> 1cm/yr) and glacio-isostatic uplift rates (> 3 cm/yr) in the Fairweather corridor highlight short-term vertical deformation at the eastern margin; however, the relationship between these rates and long-term deformation is less well known. New low-temperature cooling ages are reported …
-
INTEGRATION OF NATURAL DATA WITHIN NUMERICAL MODEL TO THE GEODYNAMICS RECONSTRUCTION OF AN INNER PART OF THE ALPINE BELT.
… prograde and retrograde thermal gradients, (iii) exhumation rates, (iv) P-T-t-paths, (v) peak and exhumation timing. Several parametrical simulations of an ocean-continent convergent system are performed to obtain the better configuration to apply for the Alpine subduction. Dur- ing these analysis …
-
Pressure, temperature, and stress conditions of Southern Alpine Fault (New Zealand) mylonites
… continental plate boundary. Due to lower exhumation rates along southern portions of the fault relative to the well-studied central Alpine Fault, deformation ages vary along strike by ~15 m.y.. Mylonites collected from two southern creeks near Haast, NZ, display a uniform recrystallized …
-
Geologic mapping and zircon (U-Th)/He thermochronology of the Avawatz Mountains, California; Implications for the eastern terminus of the Garlock fault
… 15 Ma. This age distribution is consistent with exhumation initiating in the middle Miocene (ca. 20-15 Ma), synchronous with the initiation of slip on the Garlock fault. Vertical exhumation rates calculated from ZHe data are < 1 mm/yr, which corresponds to a horizontal shortening rate of ~1 mm/yr …
-
Evaluation of Coupled Erosional Processes and Landscape Evolution in the Teton Range, Wyoming
… and cosmogenic radionuclide erosion rates were applied to determine spatial and temporal variability of erosion in the central catchments of the range. Spatial variability existed between the glacial and fluvial systems, indicating that sediment erosion and deposition by these …
-
Long-term exhumation of landscapes along the Pacific-North American plate boundary as inferred from apatite (U-Th)/He and ArcGIS analyses
… of the plate boundary reflects recent, rapid exhumation as observed in bordering mountain belts, low-temperature thermochronometry and topographic analyses were applied to each area. In the northern San Gabriel Mountains, apatite (U-Th)/He ages are >10 Ma along narrow crystalline ridges topped …
-
Tectonic-erosion interactions : insights from the paleo-drainage of the Brahmaputra River
… debated. Decoupling between of the time of rock exhumation and surface uplift has been explained by differences in rock erodibilities of the plateau between the Shillong Precambrian basement and the overlying Cenozoic sedimentary rock. New detrital zircon U-Pb data and lithospheric stress field …
-
Thermal and Diagenetic Evolution of Carboniferous Sandstones, Central Appalachian Basin
… Permian and occurred at a rate of ~100 m/m.y. Exhumation rates of ~10-30 m/m.y. from maximum burial to present depth were constrained using published apatite fission track and radiogenic helium ages. Quartz, lithic and feldspar-rich sandstones from different stratigraphic intervals and …
-
The thermal and metamorphic evolution of mountain belts as a response to erosion, accretion, and radiogenic heating
… patterns can be related to the relative rates of accretion, erosion, and plate convergence. In particular, peak metamorphic temperatures within the core of an orogen are related to ratios of accretion rate to convergence velocity; and the distance from the toe of an orogen to the …
-
Hillslope erosion and weathering rates in Earth's most rapidly uplifting mountains
Knowledge of hillslope erosion rates and processes is necessary for understanding landscape response to tectonic and climatic forcing and for determining the degree to which mountains regulate biogeochemical cycles and global climate. Landslide erosion and soil production are the principle …
-
Advances in Subduction Zone Processes
… from eclogite lithologies reveals about early exhumation of subducted terrains. The second chapter focuses on how externally-derived hydrous fluids can decarbonate subducted basalt, liberate carbon and transfer it to the overlying mantle wedge, where it can be incorporated into melt that forms …
-
Tectonic and climatic controls on orogenic processes : the Northwest Himalaya, India
… erosion, which in turn results in tectonic exhumation as an isostatic compensation process. Alternatively, subsurface structures can have significant influence in the evolution of this actively growing orogen. Along the southern Himalayan front new 40Ar/39Ar white mica and apatite fission …
-
Mesoproterozoic tectonic evolution of southwestern North America : protracted intracratonic deformation, sedimentation, and differential exhumation in Grand Canyon and the Rocky Mountain Region
… 150˚ C between about 1300 and 1250 Ma, refining exhumation rates of basement rocks just prior to Unkar deposition. Abrupt thickness and facies changes in conglomerate and dolomite of the Bass Formation associated with NE-striking monoclinal flexures indicate NW-directed syn-sedimentary …
-
Evaluating the Controls of Neogene Exhumation in the Tropical Northern Andes (colombia)
… in the tropics of South America. To obtain exhumation rates, I used thermochronology, which is a method that records—over timescales of millions of years—the rate at which rocks located at great depths within the Earth cool as they are transported to the surface through the erosion of …
-
INNOVATIVE AND CONVENTIONAL APPROACHES TO DETRITAL ZIRCON PROVENANCE ANALYSIS: LOOKING TO THE PAST, PRESENT, AND FUTURE
… During formation, zircon preferentially incorporates the element U and Th into its crystal lattice while excluding Pb, making it ideal for radiometric dating. Inexpensive and time-efficient U/Pb age acquisition techniques make zircon the mineral of choice for a majority of provenance studies. …
-
THERMOTECTONIC EVOLUTION OF THE ALASKA RANGE: LOW-TEMPERATURE THERMOCHRONOLOGIC CONSTRAINTS
… by investigating and understanding patterns of exhumation through time throughout the central and eastern Alaska Range. </p> <p>The southern Alaska continental margin is a complex boundary defined by active subduction and accretion of numerous terranes including the Yakutat microplate, the …
-
Quantifying crystalline exhumation in the Himalaya
… order to reveal details about the formation and exhumation conditions and rates and thus provide insights into the geodynamics of the most spectacular orogenic belt in the world: the Himalaya. The specific area investigated was the Kaghan Valley in Pakistan (NW Himalaya). Following closure of the …
-
Post-Orogenic Thermal History and Exhumation of the Northern Appalachian Basin: Low-Temperature Thermochronologic Constraints
… constraining thermal histories and determining exhumation rates within the upper continental crust. Low-temperature thermochronology, notably apatite fission-track thermochronology because it has a kinetic parameter (i.e. track lengths), is commonly used to constrain the tectonic history of …