歧口凹陷构造特征

依据岐口凹陷最新5 280km2超大三维地震数据体等资料,对岐口凹陷构造样式进行研究并取得以下认识:歧口凹陷内断裂可分4个级别,断裂走向以略有不同、以NE向为主,剖面形态特征可以划分为平面状、铲式、坡坪式和复杂坡坪式4种基本形态;凹陷内识别出3种新近纪发育的主要火山构造样式:火山口构造、玄武岩岩席和玄武岩盘构造;新近纪歧口凹陷构造以潜山披覆背斜和走滑作用形成的花状构造为主,浅层构造在平面上呈3个环带状分布。

STRUCTURES OF THE QIKOU SAG

According to the lastest 5 280 kilometers of super 3D seismic data from the Qikou Sag,we found that the faults in the sag could be divided into four levels in the sag and the trend of each fault is slightly different from the others and the north-east fault dominates.In cross profiles,there are four types of faults：the plane ones、shovel-like ones、slope flat ones and complicated slope flat ones.There are three kinds of volcanic rocks in the Neogene deposits in the sag in the forms of volcanic vent、basalt sheet,and basalt laccolith respectively.Buried hill drape anticlines and flower structures have been discovered.