天津蓟县长城系串岭沟组混层粘土矿物

Mix-layer Clay Minerals from Chuanlinggou Formation of Changcheng System in Jixian County,Tianjin City

为了解天津蓟县长城系串岭沟组地层中混层粘土矿物的组成和结构特征,利用X射线粉晶衍射(XRD)和高分辨透射电镜(HRTEM)对其进行了深入研究.通过对比该区粘土矿物的自然干燥片、Ca离子饱和片、Ca饱和的乙二醇膨胀片、加热到375℃和550℃的乙二醇膨胀片获取的XRD衍射峰,确定该区混层粘土矿物为伊利石/蒙脱石(I/S)不规则混层矿物和绿泥石/蒙脱石(Chl/S)不规则混层矿物.从高分辨透射电镜观察到I/S规则及不规则混层的晶格条纹像以及Chl/S不规则混层的晶格条纹像,揭示了该区I/S混层和Chl/S混层的层间堆跺结构特征.该研究为蓟县中元古界典型剖面提供了重要的混层粘土矿物的结构信息.

In order to realize the character of composition and structure of mixdayer clay minerals from Chuanlinggou Formation of Changcheng System in Jixian County, Tianjin City, X-ray powder diffraction （XRD） and high-resolution transmission electron microscope （HRTEM） are used to study the minerals. By contrasting air-dried oriented aggregate sample, Ca cation saturation sample, Ca saturated glycerol salvation sample and heated 375 ℃ and 550 ℃ of glycerol salvation samples, it is confirmed that the mix-layer clay minerals from this area is illite/smectite （I/S） order and disorder mix-layer clay minerals and chlorite/smectite （Chl/S） disorder mixdayer clay minerals. The obtained lattice images from high-resolution transmission electron microscope of I/S order and disorder mix layer minerals and Chl/S disorder mix-layer minerals show the structure character of layer stacking of I/S and Chl/S from this area. This study providers some important structure information of mix-layer clay minerals for the well-known Mesoproterozoic section of Jixian County.