青藏羌塘地块他利克甘利山早三叠纪牙形刺的发现及地质意义

青藏高原1∶25万加措、丁固幅区调填图过程中,在他利克甘利山原划为晚三叠世的地层中,首次发现了早三叠世常见牙形刺化石Parachirognathus delicatulus和Neospathodus bicostatus。根据所发现牙形刺动物特征及岩石特征,将原肖茶卡组划为硬水泉组和康鲁组,并将其时代从过去的晚三叠世修订为早三叠世。该发现填补了测区缺失早三叠世沉积记录的空白,为测区进一步研究三叠纪岩相古地理、地层划分与对比提供了新的地层依据。

Discovery of Lower- Triassic Conodonts of Talikeganli Mountain and Its Implication

In the process of regional mapping at Jiachuo and Dinggu on a scale of 1: 250, 000, the conodonts fossils as Parachirognathus delicatulus and Neospathodus bicostatus commonly observed in Lower Triassic, were firstly found within the strata of Talikeganli Mountain which was previously ascribed to Upper Triassic.The former Xiaochaka Formation is divided into the Yingshuiquan Formation and the Kanglu Formation, and previous Upper Triassic is amended to Lower Triassic according to zoogenic feature and lithology of discoverable conodonts.This discovery fills up the blank of the Lower Triassic sediment absent at the area, a new stratigraphic foundation is furnished to the further research for the Triassic petrographic paleogeography and stratigraphic division and comparison.