豫西陕渑新铝土矿成矿带构造特征及其控矿作用

豫西陕州—渑池—新安铝土矿成矿带是我国重要的铝土矿资源基地。通过野外调查、构造解析、统计分析和综合研究，总结了区域及典型矿区地质构造特征，阐明了区域构造形成机制和演化过程，建立了区域构造变形动力学概念模型，研究了不同尺度地质构造对铝土矿成矿、保存、空间分布和破坏等方面的控制作用，指出了构造研究对本区铝土矿找矿、勘查和开采的重要意义。研究表明：①本区中、新生代构造变形以断裂为主要表现形式，以形成断块和断陷构造为主要特征，是印支—中燕山期近SN向不对称挤压与左旋剪张耦合作用和晚燕山—喜山期区域伸展作用的产物；②区域上发育近EW向、NW向和NE向3组不同性质的断裂，以及由它们交叉切割形成的不同规模断块、断陷构造，对铝土矿的赋存和空间展布起着重要控制作用，保存良好的矿床主要分布于断陷盆地的北部边缘地区；③正断层在各矿区普遍发育，对矿体的完整性和连续性具有显著的破坏作用，给矿床勘查、资源储量估算和矿山开采设计造成严重的不利影响。因此，应重视和加强本区构造控矿作用研究，以更好地指导铝土矿找矿、勘查和开采实践。

Characteristics of Geological Structure and Its Ore-controlling Role in Shanzhou-Mianchi-Xin'an Bauxite Metallogenic Belt,Western Henan Province

The Shanzhou-Mianchi-Xin'an bauxite metallogenic belt in Western Henan Province is an important resource base of bauxite in China. Through field investigation， structural analysis， statistical analysis and comprehensive research， the geological structure characteristics of the region and typical mining areas have been summarized， the formation mechanism and evolution process of regional tectonics have been expounded， the conceptual model of regional tectonic deformation dynamics has been established， the control effect of different scale structures on bauxite mineralization， preservation， spatial distribution and destruction has been analyzed， and the important significance of geological structure research on bauxite prospecting， exploration and mining has been pointed out. The research results show that:① The Mesozoic-Cenozoic tectonic deformation in this area is mainly manifested by faults， with the formation of faulted blocks and faulted depression as the main characteristics. These geological formations are the product of the near south-north asymmetric extrusion and left-lateral shear-tension coupling during the Indosinian-Middle Yenshanian epoch and the regional extension during the Late Yenshanian-Himalayan epoch. ② On the regional tectonics， there are three groups of faults with different properties， including near EW， NW and NE trending， as well as faulted blocks and depressions of different scales formed by their cross cutting， which play an important role in controlling the occurrence and spatial distribution of bauxite. The well-preserved deposits are mainly distributed in the northern margin of faulted basins.③ Normal faults are widely developed in all mining areas， which have significant damage to the integrity and continuity of ore beds， and have serious adverse effects on mineral exploration， resource & reserve estimation and mining design & production. Therefore， it is necessary to pay more attention to and strengthen the structural ore-controlling research in this area，so as to better guide the bauxite prospecting， exploration and mining practice.