松辽盆地杏山地区侏罗系沉积和火山岩特征

JURASSIC SEDIMENTS AND CHARACTERISTICS OFVOLCANIC ROCKS IN XINGSHAN AREA OFSONGLIAO BASIN

杏山凹陷属于侏罗纪晚期断陷盆地,其内沉积了较厚侏罗系。它由两大类岩系组成:(1)正常碎屑岩;(2)火山岩和火山碎屑岩。侏罗系火山岩岩性比较复杂,以中酸性为主夹少量中基性火山岩。火山岩在地震剖面上可分为四种地震相:(1)强振幅低连续地震相;(2)强振幅中—高连续地震相;(3)弱振幅低连续或无反射地震相;(4)丘形或锥状地宸相。

ABSTRACT Xingshan sag is a faulted basin of late Jurassic, in which a very thick Jurassic sysiem was deposited. This system consists of two tynes of rock, (l)the normal clastic rocks and(2) volcanic rocks and volcanic detribus. The Jurassic volcanic rocks are very complex in lithology, in which Neutral-acid rocks inter-beded with a few ncutral-basic rocks are predominant .There are four seismic facies for these volcanic rocks in the seismic sections. (1) strong amplitude and low continuity seismic facies; (2) strong amplitude and middle-high continuty seismic faciesj (3) weak amplitude and low continuty or non-reflection seismic facies and (4) mound or coniform seismic facies.