scholarly journals Depositional Environment of the Upper Triassic Baluti Formation in Gara Anticline, Kurdistan Region, North Iraq: Insight from Microfacies and Biomarker Characteristics

2021 ◽  
Vol 54 (1E) ◽  
pp. 29-42
Author(s):  
Ayad Edilbi ◽  
Stephen Bowden ◽  
Abdala Y Mohamed ◽  
Govand H Sherwani
Keyword(s):  
Organic Matter ◽  
Depositional Environment ◽  
Land Plant ◽  
Low Energy ◽  
Subaerial Exposure ◽  
North Iraq ◽  
Restricted Environment ◽  
Energy Environment ◽  
Storm Deposits ◽  
Petrographic Study

The studied section is located in the core of the Gara Anticline, about 12 km southeast of Amedi Town. The Baluti Formation is generally composed of grey and green shale, calcareous, dolostone with intercalations of thinly bedded dolostones, dolomitic limestones, and silicified limestones which are occasionally brecciated. The petrographic study shows five main microfacies in the Baluti Formation namely; finely laminated dolomudstone, fossil-barren and lime mudstone, fenestral mudstone/packstone, peloids and ooids wackestone, and lithoclasts (intraclasts) grainstones. The mudstones facies with no fauna and radial-fibrous ooids can point to a protected and low energy environment. Moreover, fenestral structures are reliable criteria for identifying a tidal flat environment. The presence of the lithoclasts (intraclasts) with radial ooids and a few terrestrial fragments may represent a quiet environment, albeit one affected by infrequent storm deposits. As a supplementary to microfacies, the biomarker characterizations were used to deduce the depositional environment of the Baluti Formation. Biomarker parameters show that the Baluti Formation could be deposited in anoxic to suboxic environment, and organic matter input is more likely characterized by land plant organic matter. This study showed that the most likely paleoenvironments for the Baluti Formation were supratidal, intertidal, subtidal, and sand shoals setting. However, the lack and/or very low diversity of skeletal fauna, and the lack of subaerial exposure may indicate that some parts of the formation seem to be deposited in low energy and restricted environment (Lagoon).

THE GEOCHEMICAL CHARACTERIZATION OF AUSTRALIAN CRUDE OILS

1972 ◽  
Vol 12 (1) ◽  
pp. 125
Author(s):  
T.G. Powell ◽  
D.M. McKirdy
Keyword(s):  
Organic Matter ◽  
Organic Material ◽  
Depositional Environment ◽  
Land Plant ◽  
Crude Oils ◽  
Geochemical Characterization ◽  
Marine Organic Matter ◽  
Show Evidence ◽  
Lower Palaeozoic

Australian oils are generally light by world standards. They have API gravities greater than 35°, low sulphur and asphalt contents, and are of paraffinic or naphthenic base. The geochemical similarity of oils from the Bowen-Surat Basin, with the notable exception of the Conloi crude, is most marked in the fraction boiling above 250 °C. Oils from the Cooper, Gippsland and Otway Basins are probably derived from terrestrial organic material, but differ in their degree of maturation as indicated by n-alkane patterns. Samples from the Perth Basin exhibit a similar variation in maturity. In the Carnarvon Basin, the Windalia crude differs from those in deeper reservoirs in containing a higher proportion of oxygen-bearing, nitrogen-bearing, and sulphur-bearing compounds, another sign of a less mature oil. The East Mereenie oil displays an odd-even predominance in its n-alkane distribution which is characteristic of some Lower Palaeozoic crudes. A Papuan Basin condensate is the only available sample produced from a limestone reservoir. This probably accounts for its higher sulphur content. Two seeps obtained from the Papuan Highlands are inspissated residues which may have suffered microbiological alteration.A major control of the composition of Australian crude oils appears to be the depositional environment of the source rock. Most of the oils show evidence of having been generated, at least in part, from terrestrial (as opposed to marine) organic matter. The location of all but one of the reservoirs within sequences dominated by the sandstone - shale association is consistent with the likely contribution of land plant detritus to their source environment. Likewise, low sulphur and asphalt values reflect the scarcity of favourable carbonate-evaporite source and reservoir situations in Australia.

scholarly journals Low Energy STEM-EELS Characterization of Primitive Organic Matter and Silicates in the Meteorite LAP 02342

2018 ◽  
Vol 24 (S1) ◽  
pp. 2074-2075
Author(s):  
Bradley T. De Gregorio ◽  
Rhonda M. Stroud ◽  
Larry R. Nittler ◽  
Conel M. O’D. Alexander ◽  
Jemma Davidson ◽  
...  
Keyword(s):  
Organic Matter ◽  
Low Energy

scholarly journals Foraminiferal biostratigraphy and palaeoenviron- mental analysis of the basal part of Kalamavka formation (Late Miocene, Ierapetra Basin, Eastern Crete)

2016 ◽  
Vol 47 (1) ◽  
pp. 102
Author(s):  
H. Drinia ◽  
A. Antonarakou ◽  
M. A. Louvari
Keyword(s):  
Organic Matter ◽  
Quantitative Assessment ◽  
Bottom Water ◽  
Depositional Environment ◽  
Depth Interval ◽  
Foraminiferal Record ◽  
Water Depths ◽  
Foraminiferal Biostratigraphy ◽  
Planktonic Species

This work involves a preliminary quantitative analysis of benthic foraminifera for the purpose of the determination of palaeoenvironmental parameters (oxygenation, palaeobathymetry) of the depositional environment of the lower part of the typical section of Kalamavka Formation, in Ierapetra Basin, eastern Crete. The sediments of the studied section contain a rich foraminiferal fauna, mainly dominated by planktonic species. High resolution planktonic foraminiferal record reveals the presence of N. atlantica praeatlantica, N. acostaensis, P. siakensis suggesting an early Tortonian chronostratigraphic age. The quantitative assessment of palaeodepth, suggests deposition at middle shelf to bathyal water depths with moderate organic matter fluxes and elevated oxygen contents of the bottom water, typical for this water depth interval.

scholarly journals Brachiopod-dominated communities and depositional environment of the Guanshan Konservat-Lagerstätte, eastern Yunnan, China

2020 ◽  
Vol 178 (1) ◽  
pp. jgs2020-043 ◽  
Author(s):  
Feiyang Chen ◽  
Glenn A. Brock ◽  
Zhiliang Zhang ◽  
Brittany Laing ◽  
Xinyi Ren ◽  
...  
Keyword(s):  
Depositional Environment ◽  
Sedimentary Environment ◽  
Low Energy ◽  
Cambrian Explosion ◽  
Early Cambrian ◽  
Tissue Preservation ◽  
Content Type ◽  
Guanshan Biota ◽  
Supplementary Material ◽  
Later Phase

The Guanshan Biota is an unusual early Cambrian Konservat-Lagerstätte from China and is distinguished from all other exceptionally preserved Cambrian biotas by the dominance of brachiopods and a relatively shallow depositional environment. However, the faunal composition, overturn and sedimentology associated with the Guanshan Biota are poorly understood. This study, based on collections through the best-exposed succession of the basal Wulongqing Formation at the Shijiangjun section, Wuding County, eastern Yunnan, China recovered six major animal groups with soft tissue preservation; brachiopods vastly outnumbered all other groups. Brachiopods quickly replace arthropods as the dominant fauna following a transgression at the base of the Wulongqing Formation. A transition from a botsfordiid-, eoobolid- and acrotretid- to an acrotheloid-dominated brachiopod assemblage occurs up-section. Four episodically repeated lithofacies reveal a relatively low-energy, offshore to lower shoreface sedimentary environment at the Shijiangjun section, which is very different from the Wulongqing Formation in the Malong and Kunming areas. Multiple event flows and rapid obrution are responsible for faunal overturn and fluctuation through the section. A detailed lithofacies and palaeontological investigation of this section provides a better understanding of the processes and drivers of faunal overturn during the later phase of the Cambrian Explosion.Supplementary material: Composition and comparison of the Malong Fauna and the Guanshan Biota is are available at: https://doi.org/10.6084/m9.figshare.c.5080799

scholarly journals "Mineralogical & Petrographic Microfacies Study of the Zahraa formation (Pliocene– Pleistocene) in Sawa Lake Surrounding area- IRAQ "

2017 ◽  
Vol 4 (1) ◽  
pp. 11-20
Author(s):  
Saleh A. Lazam
Keyword(s):  
Organic Matter ◽  
Fresh Water ◽  
Depositional Environment ◽  
Water Environment ◽  
Lake Area ◽  
Surrounding Area ◽  
Thin Sections ◽  
Project Area ◽  
Mineralogical Study ◽  
Fresh Water Environment

"Mineralogical, Petorographic Microfacies study has been done on (16) samples of Zahraa formation (Pliocene – Pleistocene) of outcrop in Surrounded Sawa Lake area. The mineralogical study showed that Calcite is the main mineral within the rock formation, whereas the upper rocks of Zahraa Formation consist silty or sandy claystone is dominant in the middle and the upper portion, in addition to quartz, clay minerals, iron oxide and organic matter as insoluble residues. From thin sections study, Three main microfacies have been identified which are: Charophyte shelly bioclastic wackestone, Charophyte shelly bioclastic dolowackestone and Algal wackestone. Based on microfacies study and its fossils content, it has been possible to determine the depositional environment of Zahraa Formation which deposits in the area of the presence of Charaphytes, indicates fresh water environment. From the depositioal situation and the large extension in the project area, the type of fresh water environment is ephemeral freshen water lakes."

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