ID | 53863 |
言語 |
英語
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著者 |
Hossain, H. M. Z
Department of Petroleum and Mining Engineering, Jashore University of Science and Technology, Jashore 7408, Bangladesh
Ratul-Al-Istiak, H. M.
Department of Petroleum and Mining Engineering, Jashore University of Science and Technology, Jashore 7408, Bangladesh
Mahid, T. R.
Department of Petroleum and Mining Engineering, Jashore University of Science and Technology, Jashore 7408, Bangladesh
Ratnayake, A. S.
Faculty of Science and Technology, Uva Wellassa University, Passara Road, Badulla 90000, Sri Lanka
Naseem, S.
Department of Geology, University of Karachi, Karachi 75270, Pakistan
Hakro, A. A. A. D.
Centre for Pure & Applied Geology, University of Sindh, Jamshoro 76080, Pakistan
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内容記述(抄録等) | The middle Paleocene sub-bituminous coals and lignites in the Lakhra coalfield, Sindh Province, Pakistan were investigated to clarify source of organic matter and depositional environments in the Indus Delta. Here we present multiproxy approach such as C/N and C/S ratios, n-alkane indicators such as average chain length (ACL), carbon preference index (CPI), and aquatic index (Paq), as well as pristane/phytane (Pr/Ph) ratio, oleanane/hopane (Ole/Hop) ratio, and Ts/(Ts + Tm) ratio to evaluate the peat accumulation conditions at the Lakhra coalfield. The TOC, TN and TS contents range from 8.15 to 55.1%, 0.08 to 0.93% and 2.14 to 11.4%, respectively. The C/N ratios (51.2-96.5) indicate a dominant control of organic matter by terrestrial higher plants to the peat bog. The values of C32 hopanes 22S/(22S + 22R) and C29 sterane 20S/(20S + 20R) are 0.14-0.36 and 0.26-0.29, respectively, showing that the maturity level is immature. The depositional environment was evaluated to be lagoonal brackish water pond or marsh where depositional condition was anoxic to dysoxic based on the datasets of high sulfur contents (2.1-11.4%), low to high C/S ratios (0.7-26) and low Pr/Ph ratios (0.14-1.00) without UCM. The Lakhra coals and lignites are characterized by high C/N ratios (51-97), high oleanane/C30-hopanes ratios (<1.30), medium to high CPI ( ~2.0-9.8), medium ACL (27.6-28.7) and low to medium Paq values (0.13-0.34). According to these results, main origin of the coals was probably angiosperm reed/grass. The coals are also minorly accompanied by aquatic/ submerged plants and specific mosses without Sphagnum. The Lakhra coals are not abundant in regular steranes and characterized by high contents of diasteranes probably due to fine clay rich depositional environment.
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掲載誌名 |
Researches in Organic Geochemistry
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巻 | 36
|
号 | 1
|
開始ページ | 1
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終了ページ | 11
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ISSN | 1344-9915
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ISSN(Online) | 2189-7891
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発行日 | 2020
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DOI | |
出版者 | 日本有機地球化学会
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出版者ヨミ | ニホン ユウキ チキュウ カガク カイ
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出版者別表記 | The Japanese Association of Organic Geochemists
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資料タイプ |
学術雑誌論文
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ファイル形式 |
PDF
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関連情報 | |
関連情報URL(IsVersionOf) | http://www.ogeochem.jp/pdf/ROG_BN/vol36/v36_pp01-11.pdf
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著者版/出版社版 |
出版社版
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業績ID | 39615
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部局 |
総合理工学部
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