Kerogens of source rocks in the Nanyang depression of Nanxiang Basin are dominated by type Ⅱ

1

and type Ⅱ

2

and the organic types of the middle and lower Member Ⅱ of Hetaoyuan Formation (HF) are better than that of the Member Ⅲ of HF.The organic matters of the Member Ⅱ of HF are mainly sourced from bacteria and lower plants

while that of the Member Ⅲ of HF from plants.The organic matter abundance of the source rocks of HF are different for different sub-members.The richest one is the lower Member Ⅱ

followed by the upper Member Ⅲ.The organic matter abundance of the middle Member Ⅲ is moderate just like the middle Member Ⅲ.The upper Member Ⅱ is the lowest.The distribution area of active source rocks gradually becomes smaller upwards

and the source rocks concentrated in deep depression to the south.The resources in place by this reassessment are 104 million tons

much larger than 62 million tons by the last assessment.The resources of the middle Member Ⅲ are the largest

accounting for 37.5% of the total resources

followed by the upper Member Ⅲ

the lower and middle Member Ⅱ.The resources of the Member Ⅲ account for 59.6% of the total resources

indicating that the Member Ⅲ is the main source rocks of the Nanyang depression.However

the resource exploration maturity for the depression is quite low

indicating that the exploration potential for the depression may be large.