摘要
采用X射线衍射、偏光显微镜和扫描电镜对赋存在临泽县北部杨台洼滩盆地中白杨河组地层上部凹凸棒石黏土的矿物成分、形貌和赋存状态进行了研究。结果表明,矿物成分除黏土矿物外,还含有石英、长石、方解石、白云石、石膏等其他矿物。黏土矿物以凹凸棒石和伊利石为主,还含有一定量的绿泥石、高岭石和伊蒙混层矿物。白杨河组地层沉积时期为干旱气候,盆地中的水体不断蒸发使得石膏沉积下来,致使水体中Mg2+和Ca2+的比率和水体的碱性增大。在富Mg2+、碱性的介质条件中,二氧化硅胶体和Mg2+、Al3+、Fe3+随着水体的蒸发结晶析出凹凸棒石。
In this study,the mineral composition,morphology and occurrence state of attapulgite clays occurred in the upper part of the Neogene Baiyanghe Formation in the Yangtaiwatan basin located in northern Linze County,Gansu Province have been investigated using methods of X-ray diffraction,polarizing microscope,and scanning electron microscope.The results show that there are mainly clay minerals,with minor quartz,feldspar,calcite,dolomite,gypsum,and a little of other minerals in the attapulgite-rich bed.The clay minerals are mainly composed of attapulgite and illite,with a certain amount of chlorite,kaolinite,and interstratified illite-smectite.It is believed that the Baiyanghe Formation were deposited in a dry climate when the gypsum was deposited in basin with the water evaporation which resulted in the increase of Mg2+/Ca2+ratio and alkalinity of the residual lake water.The attapulgite was crystallized by silica colloid and Mg2+,Al3+,and Fe3+from the brine of Mg2+-rich and high alkalinity with water evaporating.
作者
张帅
刘莉辉
乔志川
刘钦甫
ZHANG Shuai;LIU Li-hui;Qiao Zhi-chuan;Liu Qin-fu(School of Geoscience and Surveying Engineering,China University of Mining&Technology(Beijing),Beijing 100083,China)
出处
《矿物学报》
CAS
CSCD
北大核心
2019年第6期690-696,共7页
Acta Mineralogica Sinica
基金
临泽县凹凸棒石产业发展开放课题(批准号：LZKFKT-1801)
关键词
凹凸棒石
成因
白杨河组
临泽县
Attapulgite
genesis
Baiyanghe Formation
Linze County
