【摘要】 本文通过对白云鄂博矿区精细的地质填图和剖面测量发现:1)矿区的蚀变矿化均围绕赋矿"白云岩"形成,在横向和纵向上均具有明显的蚀变强弱变化特征,从赋矿"白云岩"到顶底板板岩,蚀变和矿化强度逐渐减弱;2)赋矿"白云岩"呈岩枝状穿切围岩,接触带内带发育萤石化、霓石化、霓辉石化、钠闪石化和磷灰石化等蚀变,外带发育黑云母化、钾化(微斜长石化)、钠闪石化、弱萤石化、弱黄铁矿化和弱磁铁矿化蚀变;3)在白云鄂博矿区的西矿、东介勒格勒和菠萝头矿段的"白云岩"与围岩的内接触带,均发现有碳质板岩、硅质板岩、石英砂岩、闪长(玢)岩和辉长岩捕虏体;4)在赋矿"白云岩"的外部接触带发育与"白云岩"同期侵入的碱性岩,与白云鄂博碳酸岩体共同构成了一个碱性岩套组合;5)在白云鄂博矿区内识别出一条韧性剪切带,矿区内的赋矿"白云岩"均遭受了强烈的韧性变形和动态重结晶作用,各类矿石中的条带状构造既不是沉积层理,也不是岩浆流动的流线(面),而是与韧性剪切带密切相关的构造线(面)理。以上证据表明,白云鄂博赋矿"白云岩"为岩浆成因的白云石碳酸岩,但遭受了强烈的韧性剪切变形和动态重结晶作用。更多还原

【Abstract】 Detailed geological mapping and profile were survied, and the results show that: 1) There are a large alteration and mineralization zone forming around the ore-bearing "dolostone", which has obviously alteration strength variation characteristics in both transverse and longitudinal directions, and the intensity of alteration and mineralization gradually decreases from "dolostone" to the wall rocks. 2) Dolomite carbonatite intrude hanging wall slate as a carbonatite dykes, forming extensive fenitization of wall rocks,such as fireflitization, aegirlitization,aegirlitization, apatite alteration and so on. 3) All kinds of xenoliths such as slate, quartzite, dioritic porphyrite and gabbro are found in the inner contact zone between "dolomite" and the surrounding rock in the West,Dongjielegele and Boluotou sections of Bayan Obo deposit area. 4) In the outer contact zone of ore-bearing dolomite, there are alkaline rocks intrude together with carbonatite, which forms an alkaline rock suite assemblage.5) A ductile shear belt is recognized in the mine area and all the ore-bearing "dolostone" is magmatic carbonatite,rather than sedimentary dolomite, which are encountered extensively ductile deformation and dynamic recrystallization. As a consequence, the streaked structure in the ore is may be structural lineation rather than carbonatite flow structures or sedimentary bedding.更多还原