Abstract:

Gubei buried hill,with an area of 60km² and 1200m thick Paleozoic car-bonite sediments,is situated in the northeast seashore of the Jiyang Depres-sion.5 reverse faults and 2 overturned anticlines have been found here.The formation of the reverse faults and the overtured anticlines wererelated to the sinistral shear-compression of the Tanlu huge fracture andthe obstruction of Chengning uplift.A lot of fissures developed on the top ofthe anticlines due to tensil stress.After long time weathering and erosionfrom the Middle Ordovician to Middle Carboniferous,pores,caves and crevicesdeveloped in the weatherd crust of Ordovician,thus providing favourablespace for hydrocarbon enrichment.Surrounding by source sags,the buried hill has developed into secondaryoil pools with young source beds and old reservoiring beds.Majorproductive bed is the weathering crust of the upper part of the OrdovicianSystem,but the most rich positions are higher levels in the central part ofthe overturned anticlines.