塔里木盆地西北缘白垩纪大洋缺氧事件(OAE_2)  

Late Cretaceous Oceanic Anoxic Event(OAE_2) in northwestern of Tarim Basin

作　　者：宋春晖[1] 张曼[1] 魏引杰[1] 方小敏[2] 孟庆泉[1] 席党鹏[3] 

机构地区：[1]兰州大学地质科学与矿产资源学院&西部环境教育部重点实验室,兰州730000 [2]中国科学院青藏高原研究所,北京100085 [3]中国地质大学地球科学与资源学院,北京100083

出　　处：《地球环境学报》2011年第4期541-548,共8页Journal of Earth Environment

基　　金：国家973重点基础研究发展计划项目(2011CB403000;2010CB833401);国家科技重大专项子课题(2008ZX05008-001-05);国家基金项目(40872029;40902015)

摘　　要：大洋缺氧事件(OAEs)关系到碳-氧循环、古海洋-古气候变化等一系列重大科学问题。本文通过对塔里木盆地西北缘乌恰地区库孜贡苏剖面白垩系地层的沉积和生物特征以及沉积物色度、有机质和碳氧同位素指标的研究,结合前人研究成果,论证并证实该区上白垩统库克拜组存在大洋缺氧事件(0AE_2),并认为该区这次海洋缺氧条件可能存在四次(分别为OAE_(2a)、OAE_(2b)、OAE_(2c)和OAE_(2d)),它与我国西藏南部地区的OAE_2事件构成白垩纪Cenomanian-Turonian时期特提斯海伸向我国的南北两个分支,这次大洋缺氧事件可能与同期全球海平面大幅度上升有关。这对丰富我国白垩纪事件研究、查清白垩纪新特提斯洋演化以及塔里木盆地白垩纪古环境和烃源岩大规模形成等具重要意义。Oceanic Anoxic Events （OAEs） were relative with a series of important science questions, including carbon-oxygen cycle and paleocean-paleoclimatic changes. Combining with previous researches, this paper analysed the depositional feature, sediments＇ color, organic matter content and carbon-oxygen isotopes changes in Cretaceous Kuzigongsu section, which located in Wuqia area, northwestern margin of Tarim Basin, and confirmed that this area did exist Oceanic Anoxic Event 2 （OAE2）, furthermore, thought this event probably happened four times （OAE2a, OAE2b, OAE2c, OAE2d, respectively） instead of only one. There are two branches stretched into China from Tethys during Cenomanian -Turonian in the Cretaceous, including the sotlth branch where occurred OAE2 in the Tibetan region, and north branch where existed OAE2 in the northwestern of Tarim Basin, and OAE2 may be relative with the corresponding period of global sea surface rising. The conclusions are very important to the studies including Cretaceous events, Cretaceous paleo-environment in Tarim Basin and the large scale formation of source rock.

关 键 词：白垩纪 大洋缺氧事件 黑色页岩 塔里木盆地 

分 类 号：P534.53[天文地球—古生物学与地层学]