柯坪剖面中上奥陶统萨尔干组黑色页岩地球化学特征

塔里木盆地柯坪剖面中上奥陶统萨尔干组（O_2-3s）为一套厚13.4 m 的夹灰色薄层状或透镜状灰岩的黑色页岩沉积，黑色页岩有机碳含量0.65%～2.83%，平均为1.63%. 黑色页岩的累计厚度约在11～12 m，有机质类型为Ⅱ型，有机质主要源于藻类和疑源类，黑色页岩的等效镜质组反射率值为1.58%～1.61%. 其形成与中奥陶世庙坡期（相当于Caradoc 期）全球性缺氧事件有关，表现为碳同位素明显地正向偏移，推测这一阶段与缺氧事件有关的高丰度源岩在塔里木盆地分布广泛，为塔里木盆地重要的烃源岩层段。

Geochemistry of Salgan Black Shales of Middle-Upper Ordovician in Keping Outcrop, Tarim Basin

The Salgan formation of Middle-Upper Ordovician in Keping outcrop of Tarim basin is characterized by black shale deposit of 13.4 m in thickness intercalated with minor thin or lenticular limestone, with TOC of 0.65%～2.83%, averaging 1.63%, the total thickness of about 11～12 m, the organic matter of Type-II mainly originated from algae and acritarch. The equivalent vitrinite reflectance ranges from 1.58% to 1.61%. Its shape was related to global anoxic event of Caradoc period of Middle-Late Ordovician, with significant positive carbon isotopic excursion of carbonate. It is postulated that source rocks related to this event are widespread as major hydrocarbon source rocks in Tarim basin.