Results 61 to 70 of about 4,876 (147)

Spherulite in the modern aragonitic travertine stromatolite has a calcite core with exopolymers

Sedimentology, EarlyView.
ABSTRACT Spherulites are spherical to ellipsoidal particles formed by various crystalline substances and can be abiotically synthesised in the laboratory. Among various spherulite types, spherulites composed of calcium carbonate are also found in various natural environments, but their abiotic or biotic origins are still controversial.
Fumito Shiraishi, Takayuki Akimoto, Naotaka Tomioka, Satoko Motai, Yoshio Takahashi   +4 more
wiley   +1 more source

Climate conditions on the South‐Iberian Palaeomargin during the latest Pliensbachian to early Toarcian: A mineralogical and geochemical study from hemipelagic deposits

Sedimentology, EarlyView.
ABSTRACT The integrated analysis of lithofacies, mineralogy and geochemistry of the hemipelagic marine succession exposed in La Cerradura section (South‐Iberian Palaeomargin) provides new information to characterise the palaeoenvironmental conditions during the latest Pliensbachian to early Toarcian, including the Jenkyns Event.
Chaima Ayadi, Isabel Abad, Elisa Laita, Ali Mokhtar Samet, Matías Reolid   +4 more
wiley   +1 more source

Sedimentology of silica granules and haematite in the 3.47 Ga Antarctic Creek Member, Mount Ada Basalt, Western Australia

Sedimentology, EarlyView.
ABSTRACT The Paleoarchean Antarctic Creek Member of the Mount Ada Basalt, Eastern Pilbara Terrane, Western Australia, includes beds of jasper and white chert composed of sand‐sized silica granules that often contain or are mixed with silt‐sized particles of haematite.
Donald R. Lowe, Gary R. Byerly
wiley   +1 more source

Porosity Preservation in Deeply Buried (8500 m) Jurassic Calcareous Mudstones of the Vienna Basin (Austria)

Terra Nova, EarlyView.
ABSTRACT Significant porosity of more than 5% was found at depths of more than 8500 m in poorly sorted, calcareous mudstones of the Malmian Mikulov Formation. These overpressured rocks are the main hydrocarbon source rock in the Vienna Basin. Core samples from present‐day depths of 8150 m to 8550 m were analysed using X‐ray diffraction and scanning ...
Susanne Gier, Jürgen Schieber, Andrea Forstner‐Schicker, Peter Krois   +3 more
wiley   +1 more source

Diagenesis of organic-rich shale in Second Member of Kongdian Formation in Cangdong Sag and its influence on reservoir characteristics

Youqi dizhi yu caishoulu
The diagenesis and evolution of organic-rich shale have an important influence on the characteristics of shale reservoirs， but the relationship between diagenesis and reservoir characteristics of organic-rich shale in the Second Member of Kongdian
FENG Guozheng, YAN Jihua, PU Xiugang, CHEN Shiyue, YIN Lingzhi, LA Weihao, HAN Wenzhong, ZHANG Wei   +7 more
doaj   +1 more source

Diagenesis of marine-continental transitional shale from the Upper Permian Longtan Formation in southern Sichuan Basin, China

Open Geosciences
Upper Permian Longtan Formation transitional shale has become an important exploration layer, but the Longtan Formation shale (LFS) has a complex mineralogical composition, which affects the subsequent diagenesis and diagenetic evolution, and restricts ...
Yu Yu, Deng Xiaoliang, Deng Yuwei
doaj   +1 more source

Study of Diagenesis and Pore Evolution of Triassic Jialingjiang Formation in Southern Puguang Gasfield

Journal of Chemistry, 2016
The second member of Jialingjiang formation is considered to be an important gas reservoir with good exploration prospects in the southern Puguang gasfield. The diagenesis types are analyzed and different diagenetic stages are divided by analyzing carbon
Qi Chen, Quan-wen Liu, Shenjian Wang
doaj   +1 more source

Systematic Approach for Carbonate and Volcanic Facies Classification Based on Textural and Structural Variations Observed in Brazilian Pre‐Salt Acoustic Image Logs

Journal of Petroleum Geology, Volume 49, Issue 3, Page 869-906, July 2026.
ABSTRACT Facies characterization in carbonate reservoirs remains challenging due to their pronounced textural and structural heterogeneity. Variations in grain packing, cementation, and diagenetic overprints produce contrasting acoustic responses in borehole image logs, often limiting the reproducibility of facies interpretation.
Lenita de Souza Fioriti, Rodrigo César Teixeira de Gouvêa, Cleyton de Carvalho Carneiro   +2 more
wiley   +1 more source

Organic matter maturation vs clay mineralogy: A comparison for Carboniferous to Eocene sediments from the Alpine – Dinaride junction (Slovenia, Austria)

Geologija, 2002
Clay mineral diagenesis of Carboniferous to Paleogene rocks within the Alpine-Dinaric junction was studied and compared to vitrinite reflectance. Generally, there is a good fit between clay mineral diagenesis and VR. However, clay mineral alterations lag
Thomas Rainer, Uroš Herlec, Gerd Rantitsch, Reinhard F. Sachsenhofer   +3 more
doaj  

Photosynthetic primary production in the Mesoproterozoic

New Phytologist, Volume 251, Issue 1, Page 64-80, July 2026.
Summary The Mesoproterozoic atmosphere had more CO2 and less O2 than at present. While the upper ocean was oxygenated, the deeper ocean was euxinic or ferruginous. Primary production was performed by Chlorobia, Cyanobacteria, Proteobacteria, and Archaeplastida.
Patricia Sánchez‐Baracaldo, John A. Raven   +1 more
wiley   +1 more source