三塘湖盆地晚石炭世火山岩气孔和裂缝填充物特征及其成因研究  

Characteristics and origin of amygdale and crack fillers in volcanic rock of Late Carboniferous in Santanghu basin,Xinjiang

作　　者：南云[1] 柳益群[1] 周鼎武[2] 周宁超[1] 焦鑫[1] 周鹏[1] 

机构地区：[1]大陆动力学国家重点实验室西北大学地质学系,西安710069 [2]山东科技大学地球信息科学与工程学院,青岛266510

出　　处：《岩石学报》2016年第6期1901-1913,共13页Acta Petrologica Sinica

基　　金：国家自然科学基金项目(41272116);教育部科技发展中心高等学校博导基金(20106101110020);西北大学研究生创新教育项目(YZZ13008)联合资助

摘　　要：火山岩气孔和裂缝填充物作为热液流体活动的产物,携带着流体沉淀时的物理化学环境信息。本文通过钻井岩芯、岩石薄片观察,结合X射线衍射、电子探针和扫描电镜等测试分析手段,对新疆三塘湖盆地晚石炭世火山岩气孔和裂缝填充物特征及成因进行了深入研究。研究区发育两类气孔填充物:一类气孔填充物的矿物类型多样,包括绿泥石、绿鳞石、片沸石、柱沸石、浊沸石、丝光沸石、方解石、赤铁矿,矿物填充序列为绿泥石/绿鳞石→沸石→方解石,主要赋存于熔岩层上部蚀变较为强烈的灰褐色安山岩中;另一类气孔填充物主要为蒙脱石,局部可见石英,矿物填充序列为蒙脱石→石英,常赋存于熔岩层中下部蚀变较弱的深灰色安山岩中。裂缝填充物分布具明显的分带性,其中由沸石、方解石、绿鳞石填充的脉体主要发育于灰褐色安山岩中,而石英脉仅见于深灰色安山岩中。根据气孔和裂缝填充物的沉淀序列及特定矿物稳定范围,结合岩石蚀变程度,笔者认为灰褐色安山岩火山岩气孔和裂缝填充物为低温碱性流体沉淀的产物,而深灰色安山岩气孔填充物为火山物质水化蚀变的产物,局部受到后期硅质流体的影响。As products of hydrothermal activity,amygdale and crack fillers in volcanic rock carried the information of physical and chemical condition during fluid precipitation. We studied on the characteristics and origin of amygdale and crack fillers in volcanic rock of Late Carboniferous in Santanghu basin,Xinjiang,by means of the observation of drill cores and thin sections,and the analysis of Xray diffraction,electron microprobe and scanning electron microscopy. There were two kinds of amygdale fillers in the study area. One of the amygdale fillers were filled by many kinds of minerals,such as chlorite,celadonite,heulandite,epistilbite,laumontitization,mordenite,calcite and hematite. Filling sequence of minerals was chlorite / celadonite→zeolite→calcite. These fillers mainly occured in the strongly altered taupe andesite in the upper layer of lava. The other amygdale fillers were filled by smectite and quartz,which mainly distributed in weakly altered dark-gray andesite in the middle and lower layer of lava. Distribution of crack fillers was obviously zonation. Veins filled with zeolite,calcite,and celadonite mainly existed in taupe andesite,while quartz veins only distributed in darkgray andesite. According to filling sequence of amygdale and crack fillers and stable range of typical minerals and combining with the degree of rock alteration,amygdale and crack fillers of taupe andesite were the precipitated products of low-temperature alkaline fluid,while amygdale fillers of dark-gray andesite were the hydration and alteration products of volcanic material and filled by siliceous fluid locally.

关 键 词：气孔和裂缝填充物 低温碱性流体 火山岩 晚石炭世 三塘湖盆地 新疆 

分 类 号：P571[天文地球—矿物学] P588.14[天文地球—地质学]