Black shale formation in the late Paleocene/early Eocene Arctic Ocean and paleoenvironmental conditions: New results from a detailed organic petrological study
Black shale formation in the late Paleocene/early Eocene Arctic Ocean and paleoenvironmental conditions: New results from a detailed organic petrological study
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DOI：
10.1016/j.marpetgeo.2008.04.001
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发表时间：
2009-03
影响因子：
4.2
通讯作者：
Bettina Boucsein;R. Stein
中科院分区：
文献类型：
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作者：
Bettina Boucsein;R. Stein
对晚白垩世至始新世北冰洋沉积物中颗粒有机物（OM）的研究（IODP第302次考察）揭示了有关水生/海洋OM通量、生物来源、陆地物质的保存和输出的详细信息。在这里，我们提出了详细的数据，从显微组分分析，镜质组反射率测量和有机地球化学。在坎帕尼亚/古新世期间，陆源有机质的通量由改造和氧化的显微组分（镜质组，惰质组）和陆源脂质组（角质体，孢子体）表示。在始新世早期，水生有机质（高达40- 45%，片藻体，杂藻体，脂粒体，甲藻孢囊）和无定形有机质（高达50%沥青质）的峰值表明了剧烈的环境变化。这些增加水生有机质通量的事件，类似于有利于黑色页岩沉积的条件，与全球δ 13 C事件“古新世/始新世热极大”（PETM）和“埃尔莫事件”相关。淡水排放和源区附近的淡水藻类材料（盘星藻，葡萄球菌）和未成熟的陆地植物材料（corphuminite，textinite）记录。我们认为，海进期间含煤沉积物的侵蚀导致腐殖酸释放，作为始新世早期黑色页岩中沉积的沥青质岩的来源。
The study of particulate organic matter (OM) in Arctic Ocean sediments from the late Cretaceous to the Eocene (IODP Expedition 302) has revealed detailed information about the aquatic/marine OM fluxes, biological sources, preservation and export of terrestrial material. Here, we present detailed data from maceral analysis, vitrinite reflectance measurements and organic geochemistry. During the Campanian/Paleocene, fluxes of land-derived OM are indicated by reworked and oxidized macerals (vitrinite, inertinite) and terrigenous liptinite (cutinite, sporinite). In the early Eocene, drastic environmental changes are indicated by peaks in aquatic OM (up to 40–45%, lamalginite, telalginite, liptodetrinite, dinoflagellate cysts) and amorphous OM (up to 50% bituminite). These events of increased aquatic OM flux, similar to conditions favoring black shale deposition, correlate with the global δ13C events ‘Paleocene/Eocene Thermal Maximum’ (PETM) and ‘Elmo event’. Freshwater discharge and proximity of the source area are documented by freshwater algae material (Pediastrum, Botryococcus) and immature land-plant material (corphuminite, textinite). We consider that erosion of coal-bearing sediments during transgression time lead to humic acids release as a source for bituminite deposited in the early Eocene black shales.