| Time: | 2009 |
| Journal: | Earth science frontiers |
| Volumn: | 16 |
| Issue: | 2 |
| Pages: | 314-323 |
| Type: | Other |
| Author: | Youfeng Gao,Pujun Wang,Rihui Cheng,et al. |
Abstract: | The first member of the Qingshankou Formation recovered by CCSD-SK-Ⅰs borehole (China Cretaceous Continental Scientific Drilling-SongkeⅠ-the south borehole) is 81.41 m long and 100% of cores recovery. The age of the member corresponds approximately to the Turonian. The sequence and process of lithology-lithofacies and cyclic stratigraphy were revealed by a detailed core description. Six rock types(mudstone,dolostone,marl,limestone,ostracode limestone and volcanic ash)comprise the sedimentary strata. Deposition occurred in a deep lake,including six sedimentary microfacies:dolostone,marl,limestone,deep lake turbidite,deep lake mudstone and volcanic ash microfacies. The first member of the Qingshankou Formation represents eighty-one meter-scale cycles (sixth-order cycle),twenty-five fifth-order cycles,six fourth-order cycles and two third-order cycles. The occurrence and detailed description of mudstone,dolostone and volcanic ash are of significance for the study of anoxic events,source rock development and the potential linkage between lake-marine depositional events. |