摘要
候家院剖面与前人测制的赵家坝剖面虽仅相距1.5公里,但构造简单、地层连续、化石丰富,未受断层破坏,是研究大巴山西段奥陶系的理想剖面,其地层可划分为下、中奥陶统,与上覆下志留统和下伏下寒武统均为假整合接触。肯定了牯牛潭组和大田坝组的存在,修改和重新拟建了本区奥陶纪的生物分带,填补了几个空白层位的化石资料,为与邻区对比提供了新的依据。
The Zhaojiaba section in Ningqiang County is one of the key section for classification and correlation of the Ordovician system in the Daba Mountain and the southwestern China. It has been surveyed by many geologists. But in 1983 the authors discovered some faults across this section, which resulted in the stratigra-phic disappearance and the sequence complexity. Therefore, it is necessary to survey it again. So a new section, the Houjiayuan section, has been surveyed, which lies 1.5 km to the east of the former one. It is characterized by stratigraphic continunity, structural simplicity and abundant fossils. Based on the section, the authors divide the Ordovician here into two series: middle and lower ( with the lacuna of upper one), six formations, four graptolite zones and two graptolite subzones with two cephalopoda zones.
关键词
奥陶系
地层划分
生物带
stratigraphic classification, Ordovician system, biogenic zone.
