贵州大方坡缕石矿矿物岩石学特征

利用矿物成分特征、化学成分特征、矿石类型、热学性质特征及坡缕石矿成因等分析方法,对贵州大方县坡缕石进行研究,将坡缕石分为3种类型:Ⅰ型为薄至中厚板片状纤维坡缕石,Ⅱ型为薄-中厚层浸染状坡缕石,Ⅲ型为角砾状粘土状坡缕石。前两种类型坡缕石的SiO2,Al2O3质量分数(平均为54.74%,12.15%)低于苏皖地区龙王山-嘉山等地凹凸棒石;据纤维状坡缕石、浸染状坡缕石的晶体化学特征等分析认为属热液成因类型。纤维状坡缕石热学特征表明主要含吸附水、配位结晶水和沸石水,红外光谱中各频率段吸收峰形态及特征,证明了其所含水类型及结晶程度,并表现出热液型坡缕石谱线特征。

CHARACTERISTICS OF MINERAL AND CHEMICAL COMPOSITIONSOF PALYGORSKITE IN THE DAFANG AREA, GUIZHOU

Observation through microscope, chemical constitution analysis, X-ray diffraction analysis, differential thermal analysis and infrared spectrum analysis are used to study the mineral composition, ore type and mineral genesis of palygorskite in the Dafang area. The palygorskite can be classified into three types, the thin-medium bedded fibrous palygorskite, the thin-medium disseminated palygorskite and the brecciaed palygorskite. The contents of SiO2 and Al2O3 of the former 2 types are lower than those of the Attapulgite shan and Jiashan of Suwan area. Crystal chemical composition analysis indicates that the fibrous palygorskite of Dafang is hydrothermal in origin. And the observation of clay-brecciaed palygorskite by microscope shows that it is resulted from the deposition.