Abstract:

Therer are two kinds of geochemical anomaly zones in Shiwu faulted depression.One was resulted from oil gas migration along the faults formed or reactivated in the end of Nenjiang movement.The free gas in this kind of anomaly zones is still active.The other kind was formed of oil gas micro seepage.This kind of anomaly zones have high abnormal ΔC and acid degradated hydrocarbon.The geochemical anomaly zones of Sangshutai fracture and Shuanglong sturcture belong to the first kind;that of Houwujiahu and Siwujiazi Gasfields belong to the second kind.

Key words: ground surfcae geochemical exploration, fracture, micro seepage, the end of Nenjiang movement, Shiwu faulted depression