Abstract:

It is proved by geophysical stuty that the Meso-Cenozoic sediments up to 10000m laied down on the floor of Zhujiangkou basin,which has undergone three stages of development (the fault-sinking stage,fault-downwarping stage and downwarp-subsiding stage),and finally formed a single unified basin.7 boreholes sitting at the northern margin of the basin under study has revealed that the thickness of overlapped upper Tertiary rocks is up to several hundreds meters. They may be underlain by lower Tertiary rocks of 4000m,perhaps with upper Cretaceous rocks included,though these still have not been intersected yet.The basement of the basin is actually continuing from continental margin of Guangtong province,and some small continental basins developed on the main land during Cretaceous and Tertiary times may closely related with Zhujiangkou basin. The later Cretaeeous,Paleocene,Eocene and Oligocene continental rocks in these small basins are quite successive. Within them,some marine intercalations(30—160m)are found,which contain Dinoflagellates,Foraminifera,Gastropoda,Ostracoda,Pelecypoda and Anthozoa as well as stromatolites,layered gypsum,Siphonales limestones,pellet Iimestonos and algal limestones indicating an environment of intertidal zone of ingression of Zhujiangkou basin. Therefore,marine sediments must be more widespread across the Zhujiangkou basin. Obviously,it is quite significant for assessing oil and gas potential of the present basin.