西藏南部岗巴地区晚白垩世Cenomanian—Turonian集群灭绝事件后有孔虫动物群的复苏

西藏南部岗巴地区Cenomanian-Turonian界线附近发生过一次与大洋缺氧事件有关的集群灭绝事件。其后，随着海水中溶解氧含量的逐渐增加，海洋中微体古生物，尤其是有孔虫逐渐得到了恢复以至繁盛。从Turonian早期至Santonian晚期，有孔虫动物群的复苏过程经历了三个时期：残存期，复苏期及辐射期，其复苏的型式为渐变式复苏。

RECOVERY OF FORAMINIFERA FROM THE LATE CRETACEOUS CENOMANIAN-TURONIAN MASS EXTINCTION IN GAMBA, SOUTHERN TIBET

Detailed sampling was made from the Zongshan section in Gamba, southern Tibet. These samples yield increasingly diversified foraminifers, totalling 130 species assigned to 52 genera. The main task of our research is to reveal the law of foraminiferal recovery from the global Cenomanian Turonian boundary event (CTBE). After the study of the change of diversity, abundance and structure of foraminiferal faunas, three phases of the foraminiferal evolution have been recognized during the latest Cenomanian to Santonian. They include a survival phase (Early Turonian), a recovery phase (middle late Turonian) and a radiation phase (Coniacian Santonian). Foraminiferal recovery after the CTBE in Gamba belongs to a gradual recovery, which is presumably caused by the change of dissolved oxygen content in oceanic water column.