Aluminosilicate cementation of saprolites, grits and silcretes in Western Australia
Aluminosilicate cementation of saprolites, grits and silcretes in Western Australia
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西澳大利亚腐泥土、砂砾和硅质混凝土的铝硅酸盐胶结
DOI：
10.1080/00167618308729247
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
C. Butt
中科院分区：
文献类型：
--
作者：
C. Butt
摘要在西澳大利亚州Yilgarn地块的腐泥土、硬岩和硅质岩中，特别是在花岗岩地层中，发现了无定形到结晶不良的铝硅酸盐作为胶结剂。胶结物的矿物学范围从硅质水铝英石到可能源自水铝英石的高岭石-蛋白石-CT组合。水铝英石是非结晶的，没有独特的X射线或电子衍射图案，并且与乳白色二氧化硅具有密切的光学相似性。其特征在于Al/Si比为0.35-1.0，具有少量吸附的铁和钛。它以胶状空隙和脉状充填物的形式出现，并渗透到腐泥土的高岭石基质中。高岭石和蛋白石-CT具有相似的产状，高岭石的取向平行于胶体和相关条带。铝硅酸盐胶结物存在于腐泥土中，通常在上部区域，以及上覆砂砾和硅质岩中。在Yilgarn中部的Gabbin，砂砾厚达10米，含有铝硅酸盐。
Abstract Amorphous to poorly crystalline aluminosilicates have been found as cementing agents within saprolites, hardpans and silcretes, particularly in granitic terrains in the Yilgarn Block, Western Australia. The cements range mineralogically from siliceous allophane to a kaolinite‐opal‐CT assemblage probably derived from the allophane. The allophane is non‐crystalline, with no distinctive X‐ray or electron diffraction patterns, and has close optical similarities to opaline silica. It is characterised by Al/Si ratios of 0.35–1.0, with small amounts of adsorbed iron and titanium. It occurs as colloform void and vein fillings, and permeating the kaolinitic matrix of saprolites. The kaolinite and opal‐CT have a similar occurrence, with the kaolinite oriented parallel to colloform and related banding. The aluminosilicate cements are found in saprolite, usually in the upper zones, and in overlying grits and silcretes. At Gabbin, in the central Yilgarn, the grits are up to 10 m thick and have aluminosilicate...