过去曾对小秦岭西段震旦亚界做过不少工作,但未进行过较大比例尺的区测,因此野外资料不够系统,不够充分,研究程度较差,在地层划分上存在着不同认识。我队于1974-1975年,在西北大学地质系配合下,在本区开展了1∶5万区域地质调查工作。通过实测剖面和地质填图,在震旦亚界碳酸盐岩地层内采集了较为系统的迭层石。在该界上部发现了与予西罗圈组层位相当的冰积层。同时,对震旦亚界地层的接触关系、岩石 In the past, a great deal of work had been done on the Sinian sub-boundary of the western part of the Xiaoqinling Mountains, but no large-scale survey has been carried out. Therefore, the field data are not systematic enough, insufficiently studied and poorly studied. There are different understandings on stratigraphic division. Our team from 1974 to 1975, with the cooperation of the Department of Geology of Northwestern University, conducted 1: 50000 regional geological survey in this area. Through the measured sections and geological mapping, a more systematic stacking stone was collected in the Sinian sub-boundary carbonate rock formation. In the upper part of the boundary, an ice sheet similar to the pre-Seirosian formation was found. At the same time, the contact relationship with the Sinian sub-strata, rock