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Regional Sulfur Isotope Study Of The Vms Deposits In The Penokean Volcanic Belt, Nicholas M. Moleski

Masters Theses

The Penokean Volcanic Belt (PVB), located in northern Wisconsin and Upper Peninsula, Michigan hosts several volcanogenic massive sulfide deposits (VMS) including the well-known deposits of Flambeau and Crandon. The host rocks of the VMS deposits are Paleoproterozoic in age overlying Archean age basement rocks. This study provides δ³⁴S (VCDT) values for the following deposits within the PVB; (1) Eisenbrey, (2) Schoolhouse, (3) Bend, (4) Flambeau, (5) Reef, (6) Horseshoe, and (7) Back Forty, and explains the distribution of δ³⁴S values in the region.

The study reveals tight ranges of δ³⁴S values for each deposit …

Stable Isotope Investigations Of Two Components Of The Cryosphere: Snow And Icicle Formation, Thomas C. Brubaker

Masters Theses

Understanding the processes that govern the cryosphere is necessary to understand the water budget within an area that receives significant winter precipitation. This research investigates two components of the cryosphere, namely snow and icicle formation, through the application of the stable isotopes of oxygen and hydrogen.

Stable isotope measurements from precipitation collected throughout the winter of 2013-2014 are presented. The measured isotope values are in discord with known isotope effects. This discrepancy hints at a previously unexplored atmospheric phenomenon, where the enriched oxygen isotope signature of atmospheric ozone was incorporated, via photochemical reactions, into water vapor which subsequently fell as …

Mineralized Microbialites As Archives Of Environmental Evolution Of A Hypersaline Lake Basin: Laguna Negra, Catamarca Province, Argentina, Joy Buongiorno

Masters Theses

Environmental fluctuations related to climate, biological productivity, and evaporation can be recorded by sedimentary archives within lacustrine depositional systems. Sediments within terminal, closed-basin lakes are amongst the most sensitive paleoenvironmental indicators, and have great potential for permitting detailed reconstruction of environmental conditions via a variety of geochemical and isotopic proxies. Microbialites, however, have been largely overlooked as repositories of paleoenvironmental data. Here, we investigate mineralized microbialites within Laguna Negra, a high-altitude (4100 meters above sea level) hypersaline, closed-basin lake in the Argentinian Puna region and explore the potential recovery of environmental signals from these unique sedimentary archives. Mineralized microbialites within …

Geophysical And Remote Sensing Applications For A Better Understanding Of The Structural Controls On Groundwater Flow In The Lucerne Valley, California, Dale R. Dailey

Masters Theses

An integrated study was conducted in the Mojave Basin to investigate the potential role of faults and basement uplifts for groundwater flow in the Mojave Desert. Observations made include: 1) Very Low Frequency (VLF) measurements across mapped (using LIDAR and Geoeye-1 imagery) fault traces showed significant radio field dip angles indicative of presence of shallow sub-vertical, sheet-like conductors; many of the VLF tilt peaks coincided with changes in the magnetic profiles; 2) Vertical Electric Soundings indicate shallow basement west of, and parallel to, the Helendale Fault and deep saturated zones east of the fault/basement outcrop (F/B); and 3) isotopic analyses …