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Late Paleozoic Climatic Reconstruction Of Western Argentina: Glacial Extent And Deglaciation Of Southwestern Gondwana, Kathryn N. Pauls
Late Paleozoic Climatic Reconstruction Of Western Argentina: Glacial Extent And Deglaciation Of Southwestern Gondwana, Kathryn N. Pauls
Theses and Dissertations
Throughout its history Earth has experienced both icehouse and greenhouse conditions. Shifts and transitions from one end member to the other are driven by numerous driving mechanisms on global, orbital and more local scales. In particular, the late Paleozoic ice age (LPIA) is thought to have been driven by global drivers such as the drift of the Gondwanan continent across the South Pole, fluctuations in atmospheric CO2 concentrations, and Milankovitch cycles. It was also affected by more local and regional drivers such as active tectonism along accretionary margins and changes in atmospheric and oceanic circulation patterns. South American Gondwana provides …
A Quaternary Climate Record From A Uinta Mountains, Usa, Fen Core With Emphasis On Sediment Pyrolysis, Samuel Abraham Hillam
A Quaternary Climate Record From A Uinta Mountains, Usa, Fen Core With Emphasis On Sediment Pyrolysis, Samuel Abraham Hillam
Theses and Dissertations
The northern slopes of the Uinta Mountains, Utah were previously glaciated and contain many landslides. The Tokewanna Landslide is very large and lacks Quaternary faults. Presumably, increased moisture was the failure trigger. A Quaternary climate record from a cored fen, developed in a small basin between hummocks, was reconstructed using sediment pyrolysis, biomass balance, and magnetic susceptibility. Pyrolysis is used to define Hydrogen Indices that are used to delineate wetter and drier conditions based on the kerogen type - Type III being drier, and Type II wetter. The data were matched to a time/depth curve and compared to other Uinta …
Development And Validation Of A Physically Based Ela Model And Its Application To The Younger Dryas Event In The Graubünden Alps, Switzerland, Durban Gregg Keeler
Development And Validation Of A Physically Based Ela Model And Its Application To The Younger Dryas Event In The Graubünden Alps, Switzerland, Durban Gregg Keeler
Theses and Dissertations
The rapid rate of global warming currently underway highlights the need for a deeper understanding of abrupt climate change. The Younger Dryas is a Late-Glacial climate event of widespread and unusually rapid change whose study can help us address this need for increased understanding. Reconstructions from the glacial record offer important contributions to our understanding of the Younger Dryas due to (among other things) the direct physical response of glaciers to even minor perturbations in climate. Because the glacier equilibrium line altitude (ELA) provides a more explicit comparison of climate than properties such as glacier length or area, ELA methods …
Wetlands On The Thousand Lake Mountain Mega-Landslide As Paleoclimate Proxies, Ryan Andros Shurtliff
Wetlands On The Thousand Lake Mountain Mega-Landslide As Paleoclimate Proxies, Ryan Andros Shurtliff
Theses and Dissertations
The Windy Ridge mega-landslide in Wayne and Sevier Counties originated in Lates tPleistocene time as established by 14C ages on basal organic-rich clay and peat sediment from bogs that developed on the slide. The contact depth between bog and landslide was estimated using high-resolution seismic reflection to find the thickest sediment. Four bogs were cored at their depocenters, and organic material at the slide contact was used for age determinations. The oldest bog sediments ages are 10,600 ± 46, 10,556 ± 34, 12,511 ± 134, and 12,886 ± 91 calibrated years BP. Ages represent two sliding events. First, at the …
Evaluation Of Paleo-Climate For The Boise Area, Idaho, From The Last Glacial Maximum To The Present Based On Delta 2h And Delta 18o Groundwater Composition, Melissa Eileen Schlegel
Evaluation Of Paleo-Climate For The Boise Area, Idaho, From The Last Glacial Maximum To The Present Based On Delta 2h And Delta 18o Groundwater Composition, Melissa Eileen Schlegel
Theses and Dissertations
There are four distinguishable groundwater systems in the Boise area, Idaho, U.S.A., identified as modern batholith, thermal batholith, Boise frontal fault, and Nampa-Caldwell systems (Figure 1). Modern batholith and thermal batholith groundwaters are located in Tertiary to Cretaceous aged granites and granodiorites of the Atlanta lobe of the Idaho Batholith. The frontal fault system near Boise, ID defines the southeastern edge of the Idaho Batholith, and divides the batholith from the western Snake River Plain. The Nampa-Caldwell system is in the volcanic, fluvial and pluvial sediments of the western Snake River Plain. Groundwater ages for these systems are modern, 5-15 …
A Uintan (Late Middle Eocene) Flora And Fauna From The Uinta Basin, Utah, Stephen Dee Sandau
A Uintan (Late Middle Eocene) Flora And Fauna From The Uinta Basin, Utah, Stephen Dee Sandau
Theses and Dissertations
Late Middle Eocene time marks one of the most dynamic periods of the Paleogene in the western interior of North America. Analysis of an extensive, new collection of plant, invertebrate, and vertebrae fossils from the Uinta Formation in the Uinta Basin, south of Myton, Utah, USA, provides evidence of environmental change. Paleobotanical specimens are preserved in late stage Uinta Lake sediments and coarse-grained fluvial sediments which are stratigraphically 650 to 660 m above the Green River Formation. Deposition rates estimates of 18 to 55 cm/kyr, for Uinta Lake sediments in the Uinta Basin suggest a period of 1.18 Ma to …