Oceanic Anoxia during the Late Permian： Evidence from Pyrite Morphology

详细信息   

• 责任者：Yu Hao (Key Laboratory of Petroleum Resources ; Institute of Geology and Geophysics ; Chinese Academy of Sciences ; Beijing 100029 ; China) ; Chen Daizhao
• 刊名：Chinese Journal of Geology
• 出版年：2011
• 卷期：46(1)
• 关键词：黄铁矿 ; pyrite ; 缺氧环境 ; anaerobic environment ; 扬子板块 ; Yangtze Plate
• 页码：p.83-91
• 图表：5 illus., 25 refs.
• 分类号：0803
• 出版序号：20120216
• issnNo：ISSN0563-5020
• isbnNo：CN11-1937/P

摘要

In order to reconstruct the paleoredox conditions of the Yangtze River, the authors measured framboid size of pyrite in cherts and siliceous carbonates of Dalong Formation at Zhaojiaba section, Hubei Province, and Changjianggou section, Sichuan Province, respectively. The data indicate that pyrite framboids in the cherts and carbonates are mostly of primary origin, although minor idiotopic crystals showing post-depositional transformation are observed.  It suggests that, during the Late Permian, the organic-rich sediments were deposited from the extremely anoxic (even sulfidic) water columns within the intra-shelf basins (or depressions). The subsequent Permian-Triassic mass extinction could have been triggered by this extreme anoxia from the late Changxingian stage.