青海省锡铁山铅锌矿成矿元素物质场结构及深部找矿潜力

青海省柴达木盆地北缘锡铁山铅锌矿是我国大型的喷流沉积型(SEDEX)矿床,赋矿围岩主要是大理岩和片岩,浅部主要为大理岩型矿体,深部主要为片岩型矿体。系统描述了不同矿石类型中铅锌矿体与黄铁矿的空间共生关系、矿体空间形态三维变化规律;利用局部奇异性分析方法、相关性分析方法对矿区Pb、Zn、Ag、Au等成矿元素物质场结构特征及变化趋势进行了系统分析,2种分析方法均可表现元素物质场不同的结构特征,即:Pb、Zn、Au元素整体上沿着矿体的侧伏方向仍然有明显的向深部富集的趋势,且不受大理岩的影响,在片岩中物质场所反映的元素富集程度依然很强;Ag元素整体上从浅部到深部在矿化空间内均有明显的不连续富集特征。锡铁山铅锌矿水平方向上元素分带由远至近(由西向东)依次为Mn-Fe-S-Ag-Pb-Zn-S-Au,垂向上元素分带由上到下依次为Mn-S-Ag-Pb-Zn-S-Au,同时系统研究了成矿元素物质场中元素富集结构的变化规律,分析讨论了锡铁山深部找矿潜力。

Material field structure of ore-forming elements and deep prospecting potential of Xitieshan lead-zinc deposit,Qinghai Province

The Xitieshan lead-zinc deposit in Qaidam, Qinghai Province, is a large-scale SEDEX deposit in China. The host rocks are mainly marble and schist, the marble-style ore-bodies mainly exist in the shallow part and the schist-style ore-bodies mainly exist in the deep part. This paper systematically describes the spatial symbiosis relationship between lead-zinc ore-body and pyrite in different ore types and the three-dimensional spatial change rule of ore-body spatial shape. The material field structure and change trend of Pb, Zn, Ag, Au and other ore-forming elements in the mining area are systematically analyzed by the local singularity analysis method and correlation analysis method. Both analysis methods show different structural characteristics of the material field of elements, that is, Pb, Zn and Au are still obviously enriched to the depth along the side direction of the ore-body as a whole, and are not affected by marble. In the schist, the concentration of elements is still very strong, and Ag is obviously discontinuous in the mineralization space from the shallow to the deep. The element zoning in the horizontal direction of Xitieshan lead-zinc mine is Mn-Fe-S-Ag-Pb-Zn-S-Au from the far (hydrothermal center) to the near, and Mn-S-Ag-Pb-Zn-S-Au from the top to the bottom in the vertical direction. At the same time, we systematically study the change rule of element enrichment structure in the ore forming field, analyze and discuss the prospecting potential in the deep part of Xitieshan.