Results 61 to 70 of about 8,093,557 (158)

Paleoclimate, paleoweathering and paleoredox conditions of Lower Cretaceous shales from the Mural limestone, Tuape section, northern Sonora, Mexico: Constraints from clay mineralogy and geochemistry

Revista Mexicana de Ciencias Geológicas, 2018
Clay mineral analysis and major, trace and rare earth elements (REE) data were used in this study to interpret the paleoclimatic changes, paleoweathering and paleo-redox conditions in shale beds of the Tuape section of the Mural Limestone of Sonora.
Jayagopal Madhavaraju, Erik Ramírez-Montoya, Rogelio Monreal, Carlos M. González–León, Teresa Pi-Puig, Inocente G. Espinoza-Maldonado, Francisco J. Grijalva-Noriega   +6 more
doaj   +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

Tellurium and Mercury in Late Cretaceous to Early Eocene Sediments as Proxies for Volcanic Activity in the Deccan and North Atlantic Large Igneous Provinces

Geochemistry, Geophysics, Geosystems, Volume 26, Issue 2, February 2025.
Abstract Late Maastrichtian to Early Eocene sediments from Wadi Nukhul, Egypt were deposited between about 67 and 55.5 Ma during the eruption of the Deccan Traps and the North Atlantic Igneous Province (NAIP). We use Te and Hg as proxies for volcanism to constrain the timing of flood basalt volcanism relative to environmental perturbations and ...
Nils Björn Baumann, Marcel Regelous, Thierry Adatte, Anette Regelous, Karsten M. Haase, Hassan Khozyem   +5 more
wiley   +1 more source

REE characteristics of lower cretaceous limestone succession in Gumushane, NE Turkey: implications for ocean paleoredox conditions and diagenetic alteration [PDF]

, 2020
TASLI, KEMAL/0000-0003-0160-6912; Al-Aasm, Ihsan/0000-0003-2166-0561; Hollis, Cathy/0000-0002-3980-2583Trace and rare earth elements (REEs) are considered to be reliable indicators of chemical processes for the evolution of carbonate systems.
Ihsan Al-Aasm, Özyurt, Merve, M. Ziya Kırmacı, Cathy Hollis, Kemal Taslı, Raif Kandemir, Taşlı, Kemal, Kandemir, Raif, Al-Aasm, İhsan, Hollis, Cathy, Merve Özyurt, Kırmacı, M. Ziya, Hollis, Cathy; id_orcid, Tasli, Kemal, Kirmaci, M. Ziya, KIRMACI, MEHMET ZİYA, Ihsan S. Al‐Aasm   +16 more
core   +1 more source

Geochemical Insights into the Paleodepositional Environment of the Garagu Formation, Gara Anticline, Kurdistan, Northern Iraq

ARO-The Scientific Journal of Koya University
The Garagu Formation is mostly composed of carbonate layers with iron-rich horizons in the middle part. The geochemical evidence for the paleodepositional environment of the Garagu Formation in the Kurdistan Region of Iraq’s Gara anticline has been ...
Tola A. Mirza, Ibrahim M.J. Mohialdeen, Shahra O. Abdalla   +2 more
doaj   +1 more source

Sulfur‐to‐Iron Ratio as a Proxy for Degree of Organic Sulfurization

Geochemistry, Geophysics, Geosystems, Volume 26, Issue 1, January 2025.
Abstract The degree of organic sulfurization is broadly relevant yet underreported. We present a statistically significant correlation between whole rock S/Fe and the measured degree of organic sulfurization in the thermally immature Cenomanian–Turonian Eagle Ford Group.
K. L. French, J. E. Birdwell
wiley   +1 more source

Effects of Thermal Alteration on Paleoredox Proxies in Black Shales: Best Practices and Reasons for Caution and Optimism

Raw data for all figures in the manuscript by Chenyi Tu and others as "Effects of Thermal Alteration on Paleoredox Proxies in Black Shales: Best Practices and Reasons for Caution and Optimism"
Tu, Chenyi
core   +1 more source

Biogeochemical cycling of trace elements and nutrients in ferruginous waters: Constraints from a deep oligotrophic ancient lake

Limnology and Oceanography, Volume 69, Issue 11, Page 2775-2790, November 2024.
Abstract Iron‐rich, ferruginous waters were the dominant geochemical regime for most of Earth's history. Modern ferruginous waters are found in stratified, sulfur‐poor lakes, and serve as crucial analogs for biogeochemical cycling throughout Earth's past.
David J. Janssen, Adrianus Damanik, Nicolas Tournier, Julie Tolu, Lenny Winkel, Sri Yudawati Cahyarini, Hendrik Vogel   +6 more
wiley   +1 more source

Aluminium-normalised trace-element paleoredox proxies and their application to the study of the conditions of Burgess Shale-type preservation

, 2022
The paleo-ecological settings of Burgess Shale-type (BST) fossils have been the subject of extensive investigations, particularly with regard to the role of anoxia in their exceptional preservation.
C. Nedin (14112214), W. G. Powell (14112211), P. A. Johnston (2957328), P. A. Hall (10488693), C. J. Collom (14112217), K. C. Meehan (14112208), D. M. McKirdy (10488696)   +6 more
core   +1 more source

Geochemistry of Neoproterozoic shales of the Rabanpalli Formation, Bhima Basin, Northern Karnataka, southern India: implications for provenance and paleoredox conditions

Revista Mexicana de Ciencias Geológicas, 2018
The Rabanpalli Formation exhibits two types of shales, viz. grey and calcareous shales. These shales (grey and calcareous) have been analysed for major, trace, and rare earth elements to find out their source rocks characteristics and paleo-oxygenation ...
Ramasamy Nagarajan, Jayagopal Madhavaraju, Raghavendra Nagendra, John Selvamony Armstrong-Altrin, Jacques Moutte   +4 more
doaj