摘要
广西荣华锰矿位于三叠系百逢组,在该地层中发现的工业锰矿床尚未见报道。通过对该矿区大比例尺地质填图,并结合地质工程和测试分析等手段,对矿床地质背景、沉积环境、矿体和矿石特征、沉积演化等进行分析研究,推测荣华锰矿为沉积-淋滤锰帽型矿床,矿体顺层分布于靠近罗楼组碳酸盐岩的百逢组第一段泥岩、泥质粉砂岩中,严格受地层和构造控制。矿石主要由偏锰酸矿、软锰矿等组成,矿石品位偏低,伴生Co等金属元素。百逢组之下的碳酸盐岩和百逢组第一段浊积砾岩层可作为该类锰矿上下界线典型的找矿标志。中三叠世桂西北处于盆包台构造格局,中晚古生代富含锰的台地在三叠纪遭受风化剥蚀,成矿元素被带入弧后盆地。随着特提斯洋闭合,挤压作用使盆地面积变小,水位加深,氧化还原界面波动,在百逢组第一段锰元素初步富集。后右江盆地抬升露出水面遭受剥蚀,风化淋滤作用最终形成该区顺层分布的氧化锰矿床。桂西广泛出露百逢组地层,其第一段具有良好的找矿前景。
Ronghua manganese deposit located in the the Baifeng Formation in Triassic Baifeng stratum is initial reported as industrial deposit. Based on large-scale geological survey, exploration project, analytical testing and other means, we study the geological background, sedimentary environment, ore body and ore characteristics, sedimentary evolution, and so on. Ronghua manganese deposit, in which the ore bodies are controlled by the stratigraphy and structure, are distributed along the layers of mudstone, muddy siltstone and marl in Baifeng Formation, belonging to deposited-leaching cap-type manganese deposits. The low-grade ore associated Co and other metal elements consists of pyrolusite and other manganese oxide minerals. The carbonate under Baifeng Formation and turbidite conglomerate upper part of the first segment in Baifeng Formation are typical prospecting signs in northwest Guangxi where there is a large number of Baifeng Formation outcrop. There were terraces sur- rounded by basins in Triassic northwest Guangxi region. Such Mn-rich terraces formed in the late Paleozoic suf- fer from weathering denudation and the ore-forming elements were brought into the basins. When the Tethys O- cean closed, the manganese initial enrichment in the first segment in Baifeng Formation under the condition of basin area reduced, the water level deepened and fluctuations in the redox interface as the basins suffered com-pression. The oxide manganese deposits were ultimately formed through weathering and leaching, then Youjiang Basin uplift out of the water and began to accept the denudation.
出处
《现代地质》
CAS
CSCD
北大核心
2015年第4期912-921,共10页
Geoscience
基金
桂林理工大学人才引进资金资助项目(gg201103)
中国地质调查局调查项目(1212011120354)
关键词
荣华锰矿
三叠系百逢组
氧化锰矿
找矿前景
广西
Ronghua manganese deposit
Baifeng Formation in Triassic
oxide manganese
prospecting po-tential
Guangxi
