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在前人研究的基础上对岗巴地区上白垩统的划分做了厘定 ,进一步建立了晚白垩世的 1 2个浮游有孔虫化石带。根据岩性特征及化石带的研究 ,上白垩统被划分为赛诺曼期至土仑早期的冷青热组 ;土仑中期至三冬期的岗巴村口组和康潘期至马斯特里赫特期的宗山组。该区赛诺曼期与土仑期的界线位于冷青热组上部 ,以 H elvetoglobotruncana praehelvetica的初现为标志。
On the basis of previous studies, the division of Upper Cretaceous in Gamba area was determined and 12 late fossils of foraminifer foraminifera were further established. Based on the lithological characteristics and the study of fossil zones, the Upper Cretaceous is divided into the cold-warm group from the Sinai period to Tulun early age, the Gangba-Maukou group from the middle to the winter of Donglun, He Zunshan Zongshan group. The boundary between the Senengtian and Tulun periods in this area is located in the upper part of Lengqingzhan Formation, marked by the appearance of H elvetoglobotruncana praehelvetica.