Mudstone lithogeochemistry and formation conditions of Vendian deposits in the Shkapovo-Shikhan Basin

sedimentologists are chronologized from Steno ( ) to Vail ( ) who greatly contributed to the development The book of an internationally famous Japanese Pro-of sedimentology.The major events, among which are fessor of sedimentology Hakuyu Okada "The Evolution the Challenger expedition ( ) ; the Journal Seof Clastic

10.4096/jjssj.63.17

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Microbial Mats in Terrigenous Clastics: The Challenge of Identification in the Rock Record

Palaios (1999)

Jürgen Schieber

Increasingly, microbial communities are recognized for playing a potentially important role in defining and modifying surface sediment characteristics in various settings, ranging from terrestrial, through marginal marine, to continental margins. Whereas, the presence of microbial mats can be established with comparative ease in modern terrigenous clastics, their recognition in sedimentary rocks poses a big challenge. Terrigenous clastics of the Belt Supergroup (Mid-Proterozoic) show a number of features that can serve as microbial mat indicators: (A) domal buildups; (B) cohesive behavior; (C) wavy-crinkly character of laminae; (D) irregular wrinkled bed surfaces; (E) ripple patches; (F) laminae with mica enrichment; (G) irregular, curved-wrinkled impressions on bedding planes; and (H) lamina-specific distribution of early diagenetic minerals (dolomite, ferroan carbonate, pyrite). Positive identification of a fossil microbial mat requires one to find microbial filaments in life position. This is a difficult task even in the case of very favorable preservation of organic matter, and impossible to accomplish in many instances where fossil microbial mats are suspected. Nonetheless, the above features (especially when found in combination) are highly suggestive of microbial mats, and can serve as guides to sediments that may have accumulated under the influence of microbial mats. Whereas the Belt Basin examples are all from shallow-water environments, microbial mats may also have played an important role in deeper-water oxygen-deprived settings-the realm of black shale formation. In areas of modern oxygen-minimum zones, microbial mats have been found to thrive at the seafloor, profoundly influencing the chemistry of the sediment/water interface and sediment stability. Possible ancient analogs occur in a variety of black shale deposits (e.g. Jet Rock, Monterey Formation, Green River Formation), with wavy to crinkly kerogen-rich laminae being the main indication of possible microbial mat origins. Although microbial mats clearly have the ability to thrive in black shale environments, it will require more research to firmly establish whether, and how extensively, they occupied this niche in the geologic past.

Terrigenous sediment

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10.2307/3515357

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Conception of ternary diagrams of classifications of mixed mixed terrigenous clastic sediments and sedimentary rocks

International journal of innovation and applied studies (2019)

Assalé Fori Yao Paul Aka Kouamé

Terrigenous sediment

Ternary plot

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Lithofacies and diagenesis of selected conventional core from Jurassic and Early Cretaceous terrigenous clastic rocks, Scotian Basin

K M Gould Atika Karim David J. W. Piper Georgia Pe‐Piper

This Open File presents lithologic and petrographic detail from conventional cores from wells located across the Scotian Basin; specifically, from the Abenaki subbasin: the Mic Mac D-89, Mic Mac J-77, Mic Mac H-86, North Banquereau I-13, and Wyandot E-53 wells; from the Sable subbasin: the Marmora P-35, Onondaga O-95, Sable Island C-67, South Desbarres O-76 and Wenonah J-75 wells; and from the edge of the Shelburne subbasin: the Mohican I-100 well. Core samples from the Mic Mac D-89, Wyandot E-53 and Mohican I-100 wells are from the Middle Jurassic Mohican Formation; the remaining wells sampled either the extreme top of the Late Jurassic Mic Mac Formation or the Early Cretaceous Missisauga and Logan Canyon formations For all cores, except those in the Mohican Formation, detailed core logs are presented that use a lithofacies scheme previously applied to many other wells in the Scotian Basin. Diagenetic minerals have been studied in petrographic thin section, with selected minerals also studied by electron microprobe. Porosity and permeability data from core plug analysis have been compiled. Middle Jurassic Mohican Formation terrigenous sediment facies differ from those of the Early Cretaceous, reflecting the more arid climate conditions at that time. Other than the presence of early diagenetic anhydrite in the Mohican I-100 well, diagenetic minerals in sandstones are similar to those found in Early Cretaceous sandstones. A brief analysis of the differences in reservoir quality between the Sable and Abenaki subbasins shows that the Abenaki subbasin has proportionally better reservoir quality in the Cree Member, but proportionally poorer quality in the Middle Member of the Missisauga Formation and in the uppermost Jurassic Mic Mac Formation, compared to the Sable subbasin. In both subbasins, excellent reservoir quality is associated with chlorite rims on framework grains. Loss of reservoir quality is commonly related to carbonate cements, which are sparse to absent in the Cree Member and the Upper Member of the Missisauga Formation in the Abenaki subbasin. Lithofacies in the two subbasins are in part controlled by rates of subsidence and sediment supply, which were both greater in the Sable subbasin. River-mouth sandstones, which form the best quality reservoirs, are thicker in the Sable subbasin, where greater subsidence created greater accommodation. Widespread tidal-flat facies in the Abenaki subbasin host poorer quality reservoir sandstones.

Terrigenous sediment

10.4095/289629

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History of sedimentological research on clastic sediments with remarks on history of Russian sedimentology

Journal of the Sedimentological Society of Japan (2006)

Г. Л. Кириллова

10.4096/jssj.63.17

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