Advances， problems and prospect in studies of origin of salt rocks of the Paleogene Shahejie Formation in Dongpu Sag
Gao HongcanChen FaliangLiu GuangruiLiu Zhaofeng
1 Postdoctoral Program of Research Institute of Petroleum Exploration
& Development， PetroChina， Beijing 100083
2 Postdoctoral Workstation of Zhongyuan Oilfield Company， SINOPEC， Puyang 457001， Henan
3 Geophysical Research Institute of Zhongyuan Oilfield Company， SINOPEC， Puyang 457001， Henan
The research progress in the origin of salt rocks of the Shahejie Formation of Paleogene in Dongpu Sag has been summarized， which mainly includes two parts. One aspect is the studies on salt deposition mechanism， including two contrasting viewpoints “salt deposited in deep water” and “salt deposited in shallow water”. The former， mainly based on sedimentology， paleontology， structural geology， and so on， considers that the salt is deposited in a certain waterdepth， and the brine delamination is a basic form of salt sedimentation. In contrast, the latter， mainly based on sedimentology， considers that the salt is the result of continuous lake evaporation. The other aspect is the studies on the source of salt rocks， which includes seawater from marine transgression， deep subsurface hot brine and surface fresh water. The evidence for the former one includes paleontological fossils， and the other two are supported by geochemical analysis and inferation. There are six main problems in studies of origin of salt rocks in the Paleogene Shahejie Formation in Dongpu Sag. The brine delamination model is just a hypothesis in explaining salt sedimentation in the Dongpu Sag. The evidence of “salt deposited in shallow water” is not adequate. There are great differences in explaining the same phenomenon between the two viewpoints of salt formation. It is not clear whether the quantity， distribution and analytical results of the samples truly represent the features of salt rocks in the Dongpu Sag. The marine fossils should be further identified. The channels of marine transgression remain unclear. Finally， the authors put forward that three methods can be applied to research the origin of salt rock of the Paleogene Shahejie Formation in the Dongpu Sag， which include numerical simulation of doublediffusive convection， geochemical analysis and sedimentological studies.
GAO Gong-Can,CHEN Fa-Liang,LIU Guang-Juan et al. Advances， problems and prospect in studies of origin of salt rocks of the Paleogene Shahejie Formation in Dongpu Sag[J]. JOPC, 2009, 11(3): 251-264.
