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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. ...
Gold distribution in the Archean Tanzanian Craton: Evaluating the effects of intracrustal differentiation
(2013)
This study evaluates the vertical distribution of gold in the continental crust. Implementing a recently published method by Pitcairn et al. (2006a) for the chromatographic separation of gold from acid-digested rocks using ...
The role of mechanical mixing in the formation of reaction zones in subduction-related melange
(2013)
Traverses across metamorphic reaction zones at contacts between mafic rocks and ultramafic mélange matrix were analyzed in two mélange zones (Catalina Schist, Santa Catalina Island, CA, and Attic-Cycladic ...
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 ...
Forensic Geology in the Urban Environment: An Assessment of Material Transfer Behavior
(2013)
Soils and related anthropogenic materials are encountered as evidence in criminal investigations. The aim of this study was to better our understanding of soil transfer behavior in an urban environment, and to evaluate the ...
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 ...
Quantitative modeling of mantle heterogeneity and structure
(2010)
Mantle-derived rocks, particularly mid-ocean ridge basalts (MORB) and intraplate ocean island basalts (OIB), provide insights into the compositional heterogeneity and first-order structural make-up of the modern mantle; ...
Tracing Continental Weathering Using Lithium and Magnesium Isotopes
(2012)
Chemical weathering is an important mechanism that changes the mass and composition of the continental crust and regulates the global CO<sub>2</sub> cycle over geological time scales. Basalt, in particular, is the main ...