广西丹池矿带锡-多金属矿床地质地球化学特征及成矿作用

区域地质和矿床地质、地球化学特征研究表明,丹池锡-多金属矿带的形成,先后经历了两种成矿作用。早期是与晚泥盆世盆地的拉张活动有关的海底热水沉积成矿作用,晚期是与燕山晚期酸性岩浆活动有关的热液成矿作用。前者形成层状矿(化)体,后者主要形成脉状矿体。由于矿田所处的构造位置和沉积环境的不同,在各矿田(床)中两类成矿作用的强度有明显差异,结果导致了矿带中矿化的时空演变。

GEOLOGICAL AND GEOCHEMICAL CHARACTERISTICS AND MINERALIZING PROCESS OF THE DAN-CHI TIN-POLYMETALLIC MINERALIZED BELT, GUANGXI

The research of regional geology and geological and geochemical characteristics of depositsindicates that the Dan-Chi tin-polymetallic mineralized belt was formed by two types of mineralizingprocesses. Early minerogenesis was caused by submarine hot-water deposition related to extended activ-ity of the basin in late Devonian, while the late one caused by the hydrothermal mineralizing processrelated to acid magmatic activity at late Yanshan period. Owing to the former process the stratiformorebody or mineralizing body was formed, and due the latter one the veined orebody was mainlyformed. The ore-bearing hydrothermal fluid related to acid magmatic activity is a mixed hydrothermal sys-tem. The high-temperature vein near by the intrusion is obviously of magmatic hydrothermal charac-ter, but the middle-low temperature vien far from the intrusion gradually became the mixed hydrother-mal fluid and the geothermal fluid. Because of the differences of tectonic setting and depositional environment, the developmental in-tensity of two types of minerogenesis greatly differs in every orefield. It leads to the time and specechanges of the mineralization in the mineralized belt.