Depositional Sedimentary Environments

1980 ◽  
Author(s):  
Hans-Erich Reineck ◽  
Indra Bir Singh
Keyword(s):  
Sedimentary Environments

WORMS ON FILM: UNDERSTANDING THE INFAUNAL COLONISATION OF ANOXIC, MATGROUND-DOMINATED EDIACARAN–CAMBRIAN SEDIMENTARY ENVIRONMENTS

2020 ◽  
Author(s):  
Catherine S.R. Mascord ◽  
◽  
Liam G. Herringshaw ◽  
Krysia Mazik ◽  
Dan Parsons ◽  
...  
Keyword(s):  
Sedimentary Environments

scholarly journals Upper Jurassic Bedded Limestones and Early Diagenetic Dolomitized Limestones in the Light of Mineralogical, Geochemical and Sedimentological Studies; Kraków Area, Poland

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 462
Author(s):  
Marcin Krajewski ◽  
Piotr Olchowy
Keyword(s):  
Clay Minerals ◽  
Normal Wave ◽  
Upper Jurassic ◽  
Reef Facies ◽  
Sedimentary Environments ◽  
Storm Wave ◽  
Microscopic Studies ◽  
Silica Alumina ◽  
Characteristic Features ◽  
Facies Types

This paper describes and analyzes the Upper Jurassic (Lower Kimmeridgian) succession exposed in the Zakrzówek Horst, located in the Kraków area. Three distinguished facies types FT 1-FT 3 comprise several limestone varieties: sponge-microbial, pelitic-bioclastic, and partly dolomitized detrital-bioclastic. Their sedimentary environments varied from relatively deeper, attaining storm-wave base, to more shallower, probably close to normal-wave base. Characteristic features of limestones are changes in contents of CaCO3 and insoluble residuum as well as porosity values in vertical transitional zones between facies types. The investigated facies types differ in sediment porosity dependent on development of limestones and its susceptibility to mechanical compaction during the early diagenesis. The studied limestones show high CaCO3 contents and minor insoluble residuum contents comprising quartz, chalcedony and clay minerals. No distinct variability occurs in contents of magnesium, silica, alumina and iron accumulated in clay minerals, iron oxides and oxyhydroxides, as well as in the amounts of amorphous silica. Early diagenetic dolomites, which occur locally within the limestones, were unrelated to fracture systems as possible pathways responsible for transfer of solutions rich in Mg2+ ions. The possible source of Mg2+ ions might have been the pore solutions, which migrated from compacted basinal bedded facies towards reef facies or the grain-supported bedded facies developed in the adjacent areas. Microscopic studies revealed dedolomitization at the surfaces and in the inner parts of dolomite crystals. In many cases, dolomite crystals were replaced by calcite forming pseudomorphs.

scholarly journals New Recent foraminiferal genera and species from the lagoon at Madang, Papua New Guinea

1992 ◽  
Vol 11 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Martin R. Langer
Keyword(s):  
New Species ◽  
Shallow Water ◽  
Papua New Guinea ◽  
New Guinea ◽  
Coarse Grained ◽  
New Genera ◽  
Low Oxygen ◽  
Shell Surface ◽  
Sedimentary Environments ◽  
Tropical Lagoon

Abstract. Two new genera and eight new species of benthic foraminifera are described from the shallow water, tropical lagoon of Madang, Papua New Guinea. The new hauerinid genus Pseudolachlanella is characterized by juvenile cryptoquinqueloculine, adult almost massiline arranged chambers, and a slitlike, curved aperture with parallel sides and a long, slender, curved miliolid tooth. Pitella haigi n. gen., n. sp. is a new foraminifera with cryptoquinqueloculine arranged chambers, an almost entirely pitted shell surface (pseudopores) and a rounded aperture with a short simple tooth. Among the other species described as new are four hauerinids and two agglutinated foraminifera All new species described here occur sporadically in the shallow water back- and forereef environments of the lagoon (0–55m), and live infaunally and epifaunally in well-oxygenated, fine and coarse grained biogenic sediments. They are absent in muddy, organic-rich, low-oxygen sedimentary environments within bay inlets where variations of salinity are considerable.

Desert Sedimentary Environments

1971 ◽  
Vol 137 (4) ◽  
pp. 573
Author(s):  
I. G. Wilson ◽  
K. W. Glennie
Keyword(s):  
Sedimentary Environments

Patterns of Evolution of the Ediacaran Soft-Bodied Biota

2014 ◽  
Vol 88 (2) ◽  
pp. 269-283 ◽  
Author(s):  
Dmitriy Grazhdankin
Keyword(s):  
High Energy ◽  
Ecosystem Engineering ◽  
Low Energy ◽  
Geological Time ◽  
Time Intervals ◽  
Inner Shelf ◽  
Sedimentary Environments ◽  
Burrowing Activity ◽  
Ecological Associations ◽  
Channel Systems

When each of the Avalon-, Ediacara-, and Nama-type fossil assemblages are tracked through geological time, there appear to be changes in species composition and diversity, almost synchronized between different sedimentary environments, allowing a subdivision of the late Ediacaran into the Redkinian, Belomorian and Kotlinian geological time intervals. The Redkinian (580–559 Ma) is characterized by first appearance of both eumetazoan traces and macroscopic organisms (frondomorphs and vendobionts) in a form of Avalon-type communities in the inner shelf environment, whereas coeval Ediacara-type communities remained depauperate. The Belomorian (559–550 Ma) is marked by the advent of eumetazoan burrowing activity in the inner shelf, diversification of frondomorphs, migration of vendobionts from the inner shelf into higher energy environments, and appearance of tribrachiomorphs and bilateralomorphs. Ediacaran organisms formed distinctive ecological associations that coexisted in the low-energy inner shelf (Avalon-type communities), in the wave- and current-agitated shoreface (Ediacara-type communities), and in the high-energy distributary systems (Nama-type communities). The Kotlinian (550–540 Ma) witnessed an expansion of the burrowing activity into wave- and current-agitated shoreface, disappearance of vendobionts, tribrachiomorphs and bilateralomorphs in wave- and current-agitated shoreface, together with a drop in frondomorph diversity. High-energy distributary channel systems of prodeltas served as refugia for Nama-type communities that survived until the end of the Ediacaran and disappeared when the burrowing activity reached high-energy environments. This pattern is interpreted as an expression of ecosystem engineering by eumetazoans, with the Ediacaran organisms being progressively outcompeted by bilaterians.

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