徐家围子断陷火山岩赋存型式及意义

OCCURRENCES OF VOLCANIC ROCKS IN XUJIAWEIZI FAULT-DEPRESSION AND THEIR SIGNIFICANCE

程日辉 刘万洙 王璞珺 单玄龙 陈树民 曲永保

Cheng Rihui Liu Wanzhu Shan Xuanlong Chen Shuming Qu Yongbao

晚侏罗世-早白垩世是松辽盆地徐家围子断陷火山岩喷发的主要时期,其赋存型式具有一定的几何学特征,根据火山岩喷发的构造位置与其在盆地内赋存的几何学样式,可以识别出火山岩在上升盘喷发、沿断裂带喷发和在下降盘喷发3种赋存型式。不同的赋存型式往往对应不同的盆地单元构造样式,沿断裂面赋存的火山岩向盆地逐渐过渡为湖底扇-浊积扇;赋存于上升盘的火山岩则与沉积岩互层分布;下降盘赋存的火山岩多被细粒沉积物所覆盖。

The volcanic rocks in Xujiaweizi fault-depression, Songliao basin,was mainly erupted in Late Jurassic to Early Cretaceous.Their occurences are characterized by a certain geometric pattern.On the basis of the structural position of volcanic eruption and the occurrences in the basin, three types of eruption have been identified, including eruption on the upthrown side of fault, along fracture belt and on downthrown side. Different occurrences are often corresponding to different basin structures. The volcanic rocks occurring along fault plane would transit gradually to sublacustrine fan—turbidite fan; the volcanic rocks occurring on the upthrown side of fault would distribute in the manner of alternating beds of volcanic rocks and sandstones; the volcanic rocks occurring on the downthrown side have mostly been covered by fine grain sediments.

10.11743/ogg20030105