Results 61 to 70 of about 928 (188)

Seawater redox variations during the deposition of the Kimmeridge Clay Formation, United Kingdom (Upper Jurassic): evidence from molybdenum isotopes and trace metal ratios [PDF]

, 2010
The Kimmeridge Clay Formation (KCF) and its equivalents worldwide represent one of the most prolonged periods of organic carbon accumulation of the Mesozoic.
Pearce, Christopher R., Cohen, Anthony S., Coe, Angela L., Christopher R. Pearce, Angela L. Coe, Anthony S. Cohen   +5 more
core   +1 more source

Toward Calibrating for Bottom Water Oxygenation Using Magnetofossils: New Insights From Southeast Atlantic and Northeast Pacific Surface Sediments

Geophysical Research Letters, Volume 52, Issue 20, 28 October 2025.
Abstract Accurate estimation of past ocean oxygen concentrations is vital for understanding the ocean's response to global climate change, but proxies for reconstructing bottom water oxygen (BWO) are limited. Magnetofossils, produced by magnetotactic bacteria, are sensitive to redox conditions in various environments.
Pengfei Xue, Liao Chang, Rong Huang, Babette A. A. Hoogakker, Liang Yi   +4 more
wiley   +1 more source

Mineralization at Different Structural Levels in the Crust

Acta Geologica Sinica - English Edition, Volume 99, Issue 4, Page 1042-1058, August 2025.
Abstract Metallogenic research on structural levels can reveal vertical patterns of mineralization and facilitate the deep exploration of economic minerals. However, research focusing on the correlation between structural levels and mineralization remains limited.
Saisai LI, Hongrui ZHANG, Zengqian HOU
wiley   +1 more source

Climate-Provenance Effect on the Organic Matter Enrichment of the Chang 9 Source Rocks in the Central Ordos Basin, China

Geofluids, 2021
The Upper Triassic Chang 9 organic-rich sediments have been considered as effective hydrocarbon source rocks for the Mesozoic petroleum system in the Ordos Basin.
Ling Ma, Zhihuan Zhang, Weiqiu Meng
doaj   +1 more source

Impacts on Sedimentary Microbial Communities Related to Temporal Changes in Trace Metal Concentrations

Geobiology, Volume 23, Issue 4, July/August 2025.
ABSTRACT Microbial processes in marine sediments drive changes in redox conditions, ultimately controlling the cycling of elements between the dissolved and solid phases. The microbial community driving these cycles depends on trace metals, but it can also be inhibited at elevated metal concentrations.
Christopher K. Jones, Jessica M. Labonté, Lauren A. Haygood, Marta E. Torres, Gerhard Bohrmann, Timothy W. Lyons, Natascha Riedinger   +6 more
wiley   +1 more source

Organic Matter Accumulation Mechanism in the Lower Cambrian Strata from Well Luntan 1 in the Tarim Basin, NW China

Geofluids, 2021
A large amount of light crude oils have been found within 4000 to 7000 m deep strata of Cambrian, Ordovician, and Silurian reservoirs in the Tarim Basin, NW China.
Qian Deng, Haizu Zhang, Haozhe Wang, Zhiwei Wei, Bin Cheng, Shida Li, Yunpeng Wang, Oluwabamise Lekan Faboya, Zewen Liao   +8 more
doaj   +1 more source

The Global Biogeochemical Cycle of Chromium at the Earth's Surface

Global Biogeochemical Cycles, Volume 39, Issue 6, June 2025.
Abstract The biogeochemistry of Cr and its cycling in Earth's surface environments is reviewed. A synthesis and critical evaluation of the major processes controlling Cr mobility and isotope composition (δ53Cr) is presented, taking a source to sink view beginning with Cr mobilization from Earth's crust.
David J. Janssen, Kohen W. Bauer, Sylvie Bruggmann, Sean A. Crowe   +3 more
wiley   +1 more source

Elevated δ15N Linked to Inhibited Nitrification Coupled to Ammonia Volatilization in Sediments of Shallow Alkaline‐Hypersaline Lakes

Geobiology, Volume 23, Issue 2, March/April 2025.
ABSTRACT Alkaline lakes are among the most bioproductive aquatic ecosystems on Earth. The factors that ultimately limit productivity in these systems can vary, but nitrogen (N) cycling in particular has been shown to be adversely affected by high salinity, evidently due to the inhibition of nitrifying bacteria (i.e., those that convert ammonic species ...
Christopher J. Tino, Eva E. Stüeken, Daniel D. Gregory, Timothy W. Lyons   +3 more
wiley   +1 more source

Redox conditions, solute sources and biogeochemical cycling in the Orosirian ocean: Geochemical and isotopic evidence from stromatolitic carbonates of ∼1.9 Ga Tadpatri Formation, Cuddapah Basin, India

Geosystems and Geoenvironment
The Orosirian Period of the middle Paleoproterozoic Era was marked by a decline in atmospheric oxygen and a reducing ocean after a brief oxidized interval of the preceding Great Oxidation Event.
M. Ashok, Nurul Absar
doaj   +1 more source

Paleoenvironment and Organic Matter Accumulation of the Upper Ordovician-Lower Silurian, in Upper Yangtze Region, South China: Constraints from Multiple Geochemical Proxies

Energies, 2020
The origin of the organic-rich shale in the Upper Ordovician Wufeng Formation and Lower Silurian Longmaxi Formation is complex and controversial. This paper reports the geochemical data of Wufeng-Longmaxi Formations in the Upper Yangtze region to restore
Zisang Huang, Xingzhi Wang, Xiyan Yang, Rukai Zhu, Jingwei Cui, Wenrui Shi, Yiqing Zhu   +6 more
doaj   +1 more source