前言冀西北怀来、涿鹿,下花园一带属燕山的一部分,是震旦亚界青白口系下马岭组地层最发育的地区。它层序完整、界线清楚,分段明显、厚度很大,特别是在涿鹿下花园一带还含有丰富的叠层石化石。这些叠层石具有分布广泛、层位稳定、类型多样、分带明显的特点。有的类型是国内首次发现,因此也是研究青白口系叠层石的典型地区。 Foreword Northwest Hebei, Zhuolu, under the garden along the Yanshan part of the Sinian sub-Qingbaikou Formation Xiamaling Formation strata most developed areas. It has a complete sequence, clear boundaries, clear sections and large thickness, especially in the area around Zhuolu under the garden, which is also rich in laminated fossils. These strata have widely distributed, stable layers, diverse types, with obvious banding characteristics. Some types are first discovered in China, so it is also a typical area for researching the Qingbaikou stratigraphic sequence.