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.