Sökt på: a system of geology
totalt 845 träffar
Emerging Patterns in Proterozoic Lipid Biomarker Records
Diverse and abundant lipid biomarker assemblages have been reported from a variety of Proterozoic marine environments from the careful analysis of well-preserved rocks and oils. …
Lithium Isotopes
Lithium isotopes are a relatively novel tracer of present and past silicate weathering processes. Given that silicate weathering is the primary long-term method by which CO2 is …
Vanadium Isotopes
Vanadium isotope ratios (51V/50V) have potential to provide information about changes in past ocean oxygen contents. In particular, V isotopes may find utility in tracing …
Pelagic Barite
Reconstruction of ocean paleoproductivity and paleochemistry is paramount to understanding global biogeochemical cycles such as the carbon, oxygen and sulfur cycles and the …
The Pyrite Trace Element Paleo-Ocean Chemistry Proxy
The use of the trace element content of sedimentary pyrite as a proxy for the trace element composition of past oceans has recently emerged. The pyrite proxy has several potential …
Molybdenum as a Paleoredox Proxy
Molybdenum (Mo) is a widely used trace metal for investigating redox conditions. However, unanswered questions remain that concentration and bulk isotopic analysis cannot specially …
Magnesium Isotopes
Magnesium is a major constituent in silicate and carbonate minerals, the hydrosphere and the biosphere. Magnesium is constantly cycled between these reservoirs. Since each of the …
Reconstructing Precambrian pCO2 and pO2 Using Paleosols
Paleosols formed in direct contact with the Earth's atmosphere, so they can record the composition of the atmosphere through weathering processes and products. Herein we critically …
Local and Global Controls on Carbon Isotope Chemostratigraphy
Over million-year timescales, the geologic cycling of carbon controls long-term climate and the oxidation of Earth's surface. Inferences about the carbon cycle can be made from …
Cerium Anomalies and Paleoredox
Ce anomalies track changes in oxygen availability due to the anomalous redox-sensitivity of Ce compared with the other rare earth elements. The proxy systematics have been …