贵州务正道铝土矿区域成矿规律及其对整装勘查的意义

贵州大竹园是近年来取得重要找矿进展的大型铝土矿之一,黔北务正道地区也已被国家列入首批整装勘查区。为确保进一步找矿取得突破,迫切需要对大竹园铝土矿典型矿床及务正道铝土矿矿集区的成矿条件分析和成矿规律进行总结。本文通过含矿地层、构造、古气候、地貌和岩相古地理条件的分析,将大竹园组含矿岩系的分布、韩家店群成矿母岩的存在、基底黄龙组灰岩的溶蚀和向斜轴部构造的稳定延伸作为最重要的区域成矿要素,进而梳理出栗园－鹿池、张家院、大塘、新模、道真、桃园、安场和浣溪等向斜构造展布区作为整装勘查的主要目标,并分别建立了成矿模式,明确了重点勘查的找矿方向。通过2010年以来的整装勘查工作,目前已新增铝土矿资源量4.7亿吨,新发现3个超大型、4个大型和3个中型铝土矿,取得了显著的找矿效果。本文在找矿勘查实践基础上总结的成矿规律和成矿模式,为整装勘查提供了科学依据,也为今后的找矿提供了理论指导。

Metallogeny of the Wuchuan-Zheng'an-Daozhen Bauxite Orefield and Its Significance for Uncompartmentalized Prospecting in Guizhou, China

The Dazhuyuan bauxite deposit is one of the most important deposits discovered during recent decades, and the Wuchuan-Zheng'an-Daozhen bauxite area (simplified as Wuzhengdao area) has also been listed as one the first uncompartmentalized prospecting areas on the national level. In order to promote prospecting, it is urgent to summarize the characteristics of the Dazhuyuan typical deposit and the regional ore-forming condition and outline the metallogenic regularity for the Wuzhengdao bauxite area. Based on the analysis of ore-bearing strata, structure, paleoclimatology, palaeogeomorphology and palaeogeography, the distribution of ore-bearing strata (the Dazhuyuan Formation, C₂d), the existence of ore-source strata (Hanjiadian Formation, S₁hj), the dissolution of limestone from the basement (the Huanglong Formation, C₂h), and the stable stretching of syncline are identified as the most four most important key-points for the further prospecting of bauxite deposits in this area. The Liyuan-Luchi syncline, the Zhangjiayuan syncline, the Datang syncline, the Xinmo syncline, the Daozhen syncline, the Taoyuan syncline, the Anchang syncline and the Huanxi syncline have also been chosen as the main targets for uncompartmentalized prospecting and ore-genetic models for different kinds of bauxite deposits have been built, clearing the key exploration prospecting direction. Since 2012, three superlarge-scale, four large-scale and three middle-scale bauxite deposits have been discovered and about 470 million ton of bauxite have been confirmed, which show a remarkable result of uncompartmentalized prospecting in the Wuzhengdao area, North Guizhou. The regularity and ore-genetic model for bauxite deposits, based on practice, can provide scientific evidence for uncompartmentalized prospecting and further exploration in the Wuzhengdao area.