湘西南地区早震旦世湘锰期沉积相特征与成矿模式

CHARACTERISTICS PHASE AND METALLOGENIC MODLE OF SEDIMENT FACIES DURING XIANGMENG PERIODEARLY SINIAN IN SOUTHWEST HUNAN

湘西南地区早震旦世湘锰期处于浅海沉积环境,锰矿层沉积于浅海陆棚盆地亚相,而盆地中心微相才是锰矿沉积的最有利环境。沉积相受古地理、古构造、古气候控制,它们三位一体联合控制了锰矿床的形成和空间展布。根据其成矿规律,预测新路河—熟坪一带和牛坡头地区为湘西南锰矿的个成矿远景区。建立了陆源深源锰迁移至浅海陆棚盆地,经藻类生物和氨气的2作用形成锰矿的沉积成矿模式。其反应式:NH3+H2→ONH4++OH-;Mn(HCO3 )2+OH-→MnCO3↓+CO2↑+H2。

The micro-facies in basin center is the best environment for Mn ore to deposit, with manganese deposit in shallow sea shelf basin sub-phase and Xiangmeng Period of southwest Hunan in shallow sea deposit environment. Three aspects of ancient geography, ancient structure and ancient climate allied to control the form and space distribution of Mn-deposit. Xinluhe-Shuping region and Niutoupo area were forecast as 2 prospective zones according to metallogenic regulation. The modle ofmetallogenic by alga living creature and ammonia gas in the course of deep original manganese in land transferred to shallow sea shelf basin was established. The reaction formula: NH3+H2→ONH4++OH-;Mn(HCO3 )2+OH-→MnCO3↓+CO2↑+H2O.