河北唐山地区中寒武统张夏组鲕粒灰岩的岩石学研究

本区张夏组鲕粒灰岩内,广泛见到细径放射鲕和较粗的同心-放射鲕.放射鲕中存在连生体,我们称之“连生鲕”.与赵震等(1984)人工合成的静水鲕对比,区内放射鲕亦系静水条件下生成;因未见长串连生体,仅呈现数鲕(2—4个)连生,表明鲕粒生成后遭到搅动水拆开.由此可以认为,本组鲕粒灰岩属间歇高能成因模式的产物。又按该类岩石显示的成岩特征,可知本区鲕粒灰岩经历过多种成岩环境,至今仍保留较为明显的大气成岩环境的标志.

THE PETROLOGIC STUDY OF OOLITIC LIMESTONE OF ZHANGXIA SERIES OF MIDDLE CAMBRIAN IN TANGSHAN,HEBEI

We have observed widely a great deal of radio-ooides. They are fine grained, whereas the lamellae to radio-ooides, are Coarse grained in the oolite of Zhangxia Series in this region. There are linked bodies in the radio-ooides, named as "link growing ooides".These ooides are also similar to what Zhao Zhen et. al. (1984) had experimentally produced under the condition of the stagnant water. The chain of linked bodies of ooides are observed. It is indicated that after the forming of these ooides, they were separated by disturbed water. On account of this, the forming process of the oolitic limestone in this series may be considered as the model of intermittent high-energy current. In the light of the diagenetic features of these limestones, the oolite in this series might pass through several diagenetic environments, and the evidences of the meteoric diagenetic environment are prominently remained.