Results 41 to 50 of about 8,093,557 (158)

Paleoenvironmental characteristics of continental shale and its significance to organic matter enrichment: Taking the fifth member of Xujiahe Formation in Tianfu area of Sichuan Basin as an example

Open Geosciences
Lake-phase organic-rich shales are widely developed in the fifth member (Xu5 Member) of the Triassic Xujiahe Formation in the Sichuan Basin. However, due to the lack of understanding of the paleoclimate and paleoenvironment, the mechanism of organic ...
Yang Jian, Jiang Yuqiang, Chen Weihua, Pan Hui, Yang Xing, Li Miao, Liu Tao, Wang Zhanlei, Gu Yifan   +8 more
doaj   +1 more source

Iron Sources and Cycling During Diagenetic Transformations of Negev Phosphorites (Israel)

Paleoceanography and Paleoclimatology, Volume 41, Issue 4, April 2026.
Abstract The Late Cretaceous Negev area in the Levant was influenced by high productivity upwelling in southern Tethys, leading to massive deposition of phosphorites. The phosphorites occur in two facies: (a) pristine phosphorites with low phosphorous (P) content, formed under low‐energy, high‐productivity conditions, and (b) reworked phosphorites with
Irina Zweig, Alexey Kamyshny Jr., Aya Schneider‐Mor, Nadya Teutsch   +3 more
wiley   +1 more source

Unraveling the Enrichment Mechanisms of Rare Earth Elements in Deep‐Sea Sediments: An Environmental Magnetic Perspective

Geophysical Research Letters, Volume 53, Issue 4, 28 February 2026.
Abstract Deep‐sea rare earth elements and yttrium (REY)‐rich sediments have attracted considerable attention since their discovery in 2011. However, the environmental factors controlling REY enrichment remain poorly understood, largely because paleoceanographic proxies are absent in pelagic clays.
Xiangfeng He, Jianxing Liu, Dongjie Bi, Yamin Zhang, Mu Huang, Miao Yu, Fengdeng Shi, Jianhua Gao, Xuefa Shi   +8 more
wiley   +1 more source

A Rezi Rzt-1 fúrás felső-triász képződményeinek szervetlen geokémiai jellemzői (Kösseni Formáció, Keszthelyi-hegység): őskörnyezeti tanulmány | Inorganic geochemical characteristics of the Upper Triassic rocks from borehole Rezi Rzt–1 (Kössen Formation, Keszthely Mountains, Hungary): a palaeoenvironmental study [PDF]

, 2006
Tanulmányunkban a Dunántúli-középhegységből származó nori–rhaeti bitumenes márgák (Kösseni Formáció) szervetlen geokémiai adatait használtuk fel az üledékképződés őskörnyezeti viszonyainak jellemzésére.
Raucsikné Varga, Andrea Beáta, Raucsik, Béla, Peterdi, Andrea   +2 more
core   +1 more source

Organic matter characteristics in black shales of the southwestern paleogene N'kapa formation, Douala Sub-basin Cameroon: Evidence from stable isotopes and rock-eval pyrolysis

Evolving Earth
Shallow marine black shales from outcrops, river channels, drilled and dug wells in Dibombari-Kompina-Mian (Stage-1) and Pendanboko (Stage-2) of the Paleogene N'kapa Formation in Douala Sub-basin were studied.
Ngong Roger Ngia, Elie Fosso Menkem, Alexandrine N'nanga, Christopher Fuanya, Median Yongye   +4 more
doaj   +1 more source

Testing Utility of Organogeochemical Proxies to Assess Sources of Organic Matter, Paleoredox Conditions, and Thermal Maturity in Mature Marcellus Shale

Frontiers in Energy Research, 2018
It is generally accepted that in mature shales, biomarkers and pyrolysis proxies are not very helpful in understanding the source/type of organic matter (OM), paleo-redox conditions during deposition, and thermal maturity.
Vikas Agrawal, Shikha Sharma
doaj   +1 more source

Holocene Spatiotemporal Redox Variations in the Southern Baltic Sea

Frontiers in Earth Science, 2021
Low oxygen conditions in the modern Baltic Sea are exacerbated by human activities; however, anoxic conditions also prevailed naturally over the Holocene. Few studies have characterized the specific paleoredox conditions (manganous, ferruginous, euxinic)
Dalton S. Hardisty, Natascha Riedinger, Noah J. Planavsky, Dan Asael, Steven M. Bates, Timothy W. Lyons   +5 more
doaj   +1 more source

Iron–Phosphorus–Carbon Coupled Cycling in Lacustrine System of Ordos Basin During the Middle Triassic

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 2, February 2026.
Abstract Widespread organic‐rich shales are associated with perturbations in productivity or preservation conditions; however, the major controlling factors, especially the phosphorus (P) and iron (Fe) interactions and their impacts on organic carbon burial in the paleolake ecosystem remain poorly understood.
Bo Wang, Rukai Zhu, Pengcheng Ju, Quanyou Liu, Weiming Xu, Peng Li, Wang Zhang, Xinping Liang   +7 more
wiley   +1 more source

Origin and paleoenvironmental conditions of iron duricrust in the Paleogene N’kapa Formation, Douala sub-basin, Cameroon

Geosystems and Geoenvironment
This paper unravels rarely studied paleoenvironmental conditions and origin of iron duricrust in the Paleogene N’kapa Formation, Douala sub-basin, Cameroon. It integrates petrographic and geochemical techniques (mineralogy, trace, major and REEs elements)
Kevin Jorex Voufor Tsafack, Ngong Roger Ngia, Christopher Fuanya, Christopher M. Agyingi, Elie Fosso Menkem, Alexandrine N’nanga, Median Yongye, Ligbwah Victor Wotanie   +7 more
doaj   +1 more source

Pliocene–Pleistocene Redox Evolution of the Peruvian Margin: A Multi‐Proxy Approach

Paleoceanography and Paleoclimatology, Volume 41, Issue 2, February 2026.
Abstract Due to upwelling of nutrient‐rich waters, the Peruvian Margin is one of the most productive regions of the global ocean, hosting one of the most pronounced and shallowest oxygen minimum zones. This combination of high productivity and low oxygen makes the Peruvian margin a critical site for reconstructing past environmental changes.
P. L. Fraga‐Ferreira, C. Siebert, M. F. Lehmann, M. Frank, F. Scholz   +4 more
wiley   +1 more source