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Stable Isotopic Evidence for the Rise of Oxygen and Reorganization of the Sulfur Cycle from the ca. 2.3 Ga Duitschland Formation, South Africa
(2006-12-13)
Metasedimentary rocks from the Transvaal Supergroup, South Africa, were used in a stable isotopic study to investigate the evolution of the Earth's early atmosphere and early biogeochemical cycles. Sulfur isotopic evidence ...
Topographic signatures in the Himalaya: A geospatial survey of the interaction between tectonics and erosion in the Modi Khola valley, central Nepal
(2009)
Spurred by the recognition that lithologic resistivity to erosion influences the steepness of terrain, the purpose of this study is to enhance our understanding of feedbacks between erosion and tectonics in the Himalaya. ...
Diffusion of Oxygen and Lithium Isotopes at a Contact between the Bushveld Complex and Metasedimentary Rock: Implications for the Timescale of Phepane Dome Diapirism
(2009)
Within the Eastern Lobe of the Bushveld Complex, the Phepane Dome is a circular structure of metasedimentary rock hypothesized to have formed as a wallrock diapir. To constrain the duration of Phepane Dome formation using ...
ROCK FABRIC ANALYSIS OF THE SIERRA CREST SHEAR ZONE SYSTEM, CALIFORNIA: IMPLICATIONS FOR CRUSTAL-SCALE TRANSPRESSIONAL SHEAR ZONES
(2004-12-08)
Crustal-scale tabular shear zones are common features of transpressional orogens and arcs. Though foliation development in shear zones is well understood, the development of another rock fabric element, lineation, is not. ...
CONSTRAINTS ON THE DEPOSITIONAL AGES OF LESSER HIMALAYAN ROCKS IN CENTRAL NEPAL AND THEIR STRUCTURAL IMPLICATIONS
(2009)
The lack of good exposures and paucity of datable horizons in central Nepal has hindered the ability of geologists to piece together a relatively cohesive and straightforward stratigraphic succession within the Lesser ...
Rhenium-Osmium Age Determinations of Glaciogenic Shales from the Mesoproterozoic Vazante Formation, Brazil
(2006-12-12)
The Vazante Group is a sedimentary package of carbonate interbedded with diamictite and organic-rich shale, potentially representing a Pleistocene-style glacial cycle of Proterozoic age in Brazil. Lacking volcanic ashes, ...
Advection-Diffusion Controlled Lithium Isotopic Distribution in Contact Aureoles: A Case Study from the Florence County Pegmatites, Wisconsin
(2009)
Stable isotopes are useful tracers of fluid-rock interactions in contact aureole settings. To date, only a few case studies have used Li isotopes to study fluid-rock interactions in contact aureole settings. These studies ...
A CHEMICAL AND ISOTOPIC COMPARISON OF TWO 1ST-ORDER AGRICULTURAL TRIBUTARIES, KENT COUNTY, MARYLAND
(2005-05-27)
Nitrate derived predominantly from agricultural fertilizers results in algal blooms and wide-spread anoxia in estuarine environments. Roughly half the nitrate delivered to the Chesapeake Bay is derived from groundwater ...
An experimental study of silver partitioning in sulfide-oxide-melt systems at 800 degrees C
(2005-06-01)
Silver solubility, and partitioning of silver between pyrrhotite and magnetite at a(Ag) = 0.13 ± 0.04 (1σ) has been determined at 800°C, and a range of fS2 between -4.06 and -0.18 and fO2 between -14.90 and ...
TRACING SULFUR SOURCES IN AN ARCHEAN HYDROTHERMAL SYSTEM USING SULFUR MULTIPLE ISOTOPES - A CASE STUDY FROM THE KIDD CREEK VOLCANOGENIC MASSIVE SULFIDE DEPOSIT
(2005-07-07)
Mass-independent fractionation of sulfur isotopes in the Archean atmosphere resulted in surface sulfur reservoirs with distinct isotopic signatures. These signatures are used to trace the movement of sulfur through an ...