A new understanding about the volcanic distribution characteristics and eruption mechanism of Yingchen Formation in Xujiaweizi fault depression.

作者：Jiang ChuanJin^*; Chen ShuMin; Chu LiLan; Wang GuangYing; Ju LinBo

来源：Acta Petrologica Sinica, 2010, 26(1): 63-72.

• Xujiaweizi fault depression
• Yingcheng Formation
• Volcanic distribution characteristics
• Volcanic eruption mechanism
• Seismic data

Based on well data and concatenating processed 3D seismic data of the deep layer in Xujiaweizi fault depression, also with the isotopic age determination technique, a research about volcanic distribution characteristics and volcanic eruption mechanism is carried out. The volcanic rock of Yingcheng Formation is widely distributed along each large fault in Xujiaweizi fault depression, Songliao basin, like a string of beads with great thickness. The volcanic rock of Yingcheng Formation is divided into two sets: The lower set is the first member and the upper set is the third member. The first member distributes in the middle and north area of the depression, with a predominantly acidic volcanic lithology. The third member distributes in the middle and south area of the depression, with acidic, intermediate and basic volcanics developed. The fault structures and its combined characteristics in Xujiaweizi fault depression are very complicated. Normal fault, reverse fault, strike-slip fault and flower-pattern fault are all developed in this area. The convergence area of the faults of two directions is the main magma eruption channel. The time-space distribution relations of the large deep faults and volcanic rocks show that Xuzhong fault controls the magma eruption and the volcanic distribution of the first member of Yingcheng Formation. The magma mainly erupted from north to south in turn. During the third member period, the magma mainly developed along Xudong flower-pattern fault zone, erupting from South to north in turn, with basic and acidic volcanics developed alternately. Meantime, the volcanic eruption pattern of Yingcheng Formation can be summarized as fissure volcanic eruption, central volcanic eruption and Compound Volcanic eruption. The volcanic rock of Yingcheng Formation in Xujiaweizi fault depression has ail excellent storage capability and is adjacent to the source rocks. It is suited well with fault, source rock and cap rock, building up a favorable source-reservoir-cap combination, which reveals a better prospect for gas exploration.

• 出版日期2010-1
• 单位东北石油大学