金红石矿床的类型、分布及其主要地质特征

Genetic types,distribution and main geological characteristics of rutile deposits

金红石及其同质多象(锐钛矿)是钛的氧化物中最具经济意义的矿产资源,也是中国当前短缺和重要的急需矿种之一。金红石矿床产出的大地构造背景主要是古老地盾区及其边缘或褶皱带中的变质地体。全球范围内,主要的金红石矿床可分为4个大类,即:变质的、与侵入岩有关的、沉积的和风化的,它们又可以分为12个类型,其中,第四纪海滨沉积砂矿是最重要的类型,榴辉岩型、碱性岩风化型和河流沉积砂矿型次之;碱性辉石岩中的钙钛矿、角闪岩型和斑岩铜(钼)矿伴生的金红石矿床经济潜力很大。大多数金红石富矿床来自榴辉岩型、与侵入岩有关的热液交代型和深度风化的碱性岩型,但在变质(粉)砂岩型和古沉积砂矿型中也有富矿床产出。

Rutile and its isomeric mineral-anatase have the most important economic significance among titanium mineral resources and constitute one of the badly needed mineral resources currently in China. The major rutile deposits may be divided into four types, namely, metamorphic, igneous-related, sedimentary, and weathered. They may be further divided into 12 sub-types. Among them, the young sedimentary rutile deposits are economically most important, followed by eclogite type and deeply weathered alkalic pyroxenites. Some deposit types, such as rutile from amphibolite, and rutile byproduct from porphyry Cu-Mo deposits, are likely to become economic resources in the near future. Geotectonically, the futile deposits are mostly distributed in ancient shields and their margins as well as within metamorphic terranes of the folding regions. Most of rutile-rich ores came from deposits of eclogite type, metasomatic zones of igneous-related deposits, and deeply weathrerd alkalic pyroxenites. Nevertheless, in metamorphic sandstone （siltstone） deposits and ancient placer deposits, rich ores may also occur.