CAJ | 학술논문

四川盆地震旦系灯影组"葡萄花边"状白云岩横向分布范围广,纵向发育层位局限,仅在灯影组二段中下部出现,可以作为野外露头以及井下岩心的地层识别标志.以钻井岩心与野外露头样品的宏观、微观特征为基础,阐明了"葡萄花边"状白云岩的命名依据,镜下微观视域内该类岩石包括围岩、"葡萄花边"纹层、亮晶白云石三种结构组分.结合对"葡萄花边"状白云岩不同结构组分微区取样的多参数实验分析,认为成因机制上,围岩沉积于正常海水环境,"葡萄花边"是在岩石已存在的缝-洞空间中生长的胶结物,灯影组二段沉积时期海平面经历了多期次的升降运动,当海平面下降时,刚固结不久的地层暴露受到溶蚀并形成规模不等的岩溶缝洞体以及岩溶角砾,当海平面再次上升时,在缝洞体中以及角砾周缘开始形成多期次的纤状白云石胶结物,当地层埋深到一定程度时,深部热液流体会在残余缝洞系统中形成一些亮晶白云石."葡萄花边"状白云岩不但可以成为灯影组一种重要的储集岩类型,而且可以作为灯影组沉积古地貌研究的一种辅助性标志.
사천분지진단계등영조"포도화변"상백운암횡향분포범위엄,종향발육층위국한,부재등영조이단중하부출현,가이작위야외로두이급정하암심적지층식별표지.이찬정암심여야외로두양품적굉관、미관특정위기출,천명료"포도화변"상백운암적명명의거,경하미관시역내해류암석포괄위암、"포도화변"문층、량정백운석삼충결구조분.결합대"포도화변"상백운암불동결구조분미구취양적다삼수실험분석,인위성인궤제상,위암침적우정상해수배경,"포도화변"시재암석이존재적봉-동공간중생장적효결물,등영조이단침적시기해평면경력료다기차적승강운동,당해평면하강시,강고결불구적지층폭로수도용식병형성규모불등적암용봉동체이급암용각력,당해평면재차상승시,재봉동체중이급각력주연개시형성다기차적섬상백운석효결물,당지층매심도일정정도시,심부열액류체회재잔여봉동계통중형성일사량정백운석."포도화변"상백운암불단가이성위등영조일충중요적저집암류형,이차가이작위등영조침적고지모연구적일충보조성표지.
A kind of dolostone with "grape-lace shaped" cement is present in Upper Sinian Dengying Formation in Sichuan Basin.Because it is widely distributed in lateral but limited only in the middle-lower part of Member 2 in longitudinal,it can be deemed as an identification mark for outcrops and rock cores.Based on macroscopic and microscopic characteristics in lithologic samples,this kind of rock,which is defined as "grape-lace shaped"dolostone,is comprised of three textures in microphotograph,i.e.surrounding rock,"grape-lace shaped" lamina and dolosparite.The origin of cement in this dolostone is analyzed and described.