Physical Sciences and Mathematics Commons^™

An Integrated Study Of The South-Central Part Of The Springerville Volcanic Field; The Final Piece, Marissa Mnich

Masters Theses 1911 - February 2014

The Springerville Volcanic Field (SVF) is a monogenetic volcanic field located in east-central Arizona and is the southernmost of several late Pliocene to Holocene volcanic fields along the margin of the Colorado Plateau. It encompasses an area of over 3000 km² and consists of over 450 vents, most of which are cinder cones, which produced mainly basaltic flows, between 2.1 and 0.3 Ma. About 85% of the SVF was previously mapped in detail by Condit, Crumpler and Aubele (1999). In the summers of 2010 and 2011, mapping was completed in the remaining portion of the field known as the …

Holocene Paleo-Environmental Variability Reconstructed From A Lake Sediment Record From Southeast Greenland, Gregory A. De Wet

Masters Theses 1911 - February 2014

Arctic climate variability over the Holocene has been both extensive and, at times, abrupt. Current understanding of these changes is still quite limited with few high-resolution paleoclimate records available for this period. In order to place observed and predicted 21^st century climate change in perspective, reliable and highly resolved paleo-reconstructions of Arctic climate are essential. Using an 8.5 m sediment core from Nanerersarpik Lake, this project will characterize climate changes during the Holocene, including the deglacial transition, the rapid changes that are known to have occurred around 8,200 years ago, the transition from Holocene thermal maximum (HTM) to the …

7700 Years Of Holocene Climatic Variability In Sermilik Valley, Southeast Greenland Inferred From Lake Sediments, Samuel H. Davin

Masters Theses 1911 - February 2014

During the latter half of the 20^th century until present day there has been an unprecedented rise in global annual mean temperatures accompanied by rising sea levels and a decrease in Northern Hemisphere snow cover, which if it continues will lead to widespread disruption of climate patterns, ecosystems, and present-day landscapes. It is therefore of critical importance to establish an expanded network of paleoclimate records across the globe in order to better assesses how the global climate system has changed in the past, that we may create a metric by which to address modern change. Herein is presented a7,700 …

Deciphering The Age And Significance Of The Cora Lake Shear Zone: Athabasca Granulite Terrane, Northern Saskatchewan, Sean P. Regan

Masters Theses 1911 - February 2014

Interpreting the tectonic significance of high strain zones requires detailed knowledge of the P-T-t-D history of rocks on either side and of tectonized rocks within the shear zone. In-situ monazite geochronology is particularly useful because it generates a time-integrated framework of metamorphism and fabric development. This can be achieved by correlating monazite compositional domains with the growth and consumption of major phases. Furthermore, monazite can be a fabric forming mineral, and can be directly linked to structural fabrics and kinematics. The Cora Lake shear zone (CLsz) represents a major lithotectonic discontinuity within the deep crustal Athabasca Granulite terrain, and preserves …

Biomarker And Sedimentological Investigations Of Mis 8 Through Mis 12 From Lake El'gygytgyn, Ne Arctic Russia, Jeremy H. Wei

Masters Theses 1911 - February 2014

Abstract

Multiple proxy analysis of lake sediment records are crucial for understanding changes in environmental and climate conditions over historical and geological time. Most recently, the use of biomarker proxies coupled with sedimentological investigations provides a new approach for gaining insight into the lake processes that capture information about past climate change. This approach is applied here to better understand the paleoclimate record from Lake El’gygytgyn in Western Beringia. Multiple organic geochemical compound concentrations were measure as proxies for both aquatic and terrestrial biological productivity. Measurements of n-alkane (plant leaf waxes) as well as concentrations of the compounds arborinol …

Biogeochemical Evidence For Hydrologic Change During The Holocene In A Lake Sediment Record From Southeast Greenland, Nicholas L. Balascio, William J. D'Andrea, Raymond S. Bradley, Bianca B. Perren

Raymond S Bradley

Holocene paleoclimate records from Greenland help us understand the response of the Greenland Ice Sheet and regional oceanic and atmospheric circulation systems to natural climate variability in order to place recent changes in a longer-term perspective. Here biogeochemical analysis of a lake sediment core from southeast Greenland is used to define changes in moisture balance and runoff during the Holocene in a catchment near the margin of the Greenland Ice Sheet. A 1.6 m sediment core that spans the last 8.8 ka was recovered from Flower Valley Lake on Ammassalik Island. Magnetic susceptibility, diatoms, bulk biogeochemical properties (TOC, C/N, δ13Corg), …