内蒙古东北地区上古生界伊利石研究

内蒙古东北地区上古生界主要是一套泥质岩石,其详细深入的矿物学工作尚不多见.本文利用JSM-6700F场发射电镜及INCA能谱仪,探讨了伊利石在成岩.极低级变质作用过程中的行为.采用D/max-2500 X-射线衍射仪,研究了伊利石的结晶度、多型和b0值.伊利石结晶度变化于0.28～0.77,除去构造应力对伊利石结晶度指数值的影响,研究区伊利石结晶度指数应>0.34,反映晚古生代地层主体属于晚期成岩带和低级近变质带.伊利石(白云母)多型分三种类型,分别是1Md型、1Md+2M1混合型和2M1型,是晚期成岩带和低级近变质带的产物.伊利石(白云母)b0值变化于8.9892 ～9.0404 之间,b0平均值9.0196 ,属中压相.

Study of illite in the Upper Paleozoic, in northeastern Inner Mongolia

Lithology of Upper Paleozoic in Inner Mongolia mainly is pelitic rocks. Mineralogy study in detail in this area is still not been carried. By using JSM-6700F field emission scanning electron microscope and INCA EDS, this paper discusses behavior of illite during diagenesis and very low grade metamorphism. Study illite crystallinity, polytype and b dimension by using D/mas-2500X-ray diffractometer. Illite crystallinity range from 0. 28 to 0.77. Removing tectonic stress influence on illite crystallinity, illite crystallinity should be larger than 0.34 in this area. And illite crystallinity reflect that Late Paleozoic formation belong to late diagenetic zone and low anchizone. Illite (muscovite) polytype is 1M_d type, 1M_d+2M_1 mixing type and 2M_1 type, which is the production of late diagenetic zone and low anchizone. Illite (muscovite) b dimension rang from 8.9892 A to 9.0404A, average b dimension is 9.0196A, middle pressure phase.