寿光磁异常区找矿方向探讨

Study on Prospecting Shouguang Magnetic Anomaly

摘要:

寿光磁异常是山东仅次于济宁的第二大磁异常。由山东省第四地质矿产勘查院实施的ZK401验证孔，在孔深856.22～1600.87m处见中生代白垩纪青山群八亩地组地层，是一套玄武安山安山岩石组合，认为寿光磁异常是具有磁性的中生代火山岩系引起的。该文依据寿光磁异常区的重、磁异常特征，结合所处的地质构造环境，通过反演磁性体的空间分布形态，推断寿光磁性体是夹持在前古生代地层（寒武系）间的类似山顶到山谷的一个楔型火山岩盆地。套用火山机构的划分模式，把磁性体所处的潜火山岩细分为火山喷发沉积岩相、火山通道相和重熔侵入岩相等3个岩相。依据火山岩相与矿产的关系，认为寿光火山岩系的深部可能有规模较大的岩浆岩型铁矿存在。寿光磁性体的中、深部的火山通道相是金、铜、铅、锌、钼等矿产的富集场所，是今后勘查找矿的重点靶区。

Abstract:

Shouguang magnetic anomaly is the second largest magnetic anomaly after Jining magnetic anomaly. As showed by the ZK401 hole implemented by No.4 Exploration Institute of Geological and Mineral Resources, in the hole depth at 856.22~1600.87m, strata of Babudi formation in Mesozoic Cretaceous Qingshan group can be seen. It is a basaltic andesite andesite stone combinations. Shouguang magnetic anomaly was formed by Mesozoic volcanic rocks with magnetic. According to characteristics of gravity anomaly and magnetic anomaly in Shouguang magnetic anomaly area, combining with geological and structural environment, through inversion of the spatial distribution of magnetic body shape, it is concluded that Shouguang magnetic body is a wedgeshaped volcanic basin between the summit to the valley in Paleozoic (Cambrian) strata. By using division model of volcanic apparatus, subvolcanic rocks can be divided into volcanic eruption sedimentary petrography lithofacies, subvolcano lithofacies, volcanic vent lithofacies and remeltingintruded rock lithofacies. According to the ralation between the volcanic rock lithofacies and mineral products, it is thought that there maybe exit a largescale magmatic rock iron ore in the deep of Shouguang volcanic rock. In the middle and the deep parts of volcanic vent lithofacies and the distribution regions of subvolcano lithofacies, there are rich minerals, such as gold, copper, lead, zinc and Mu, etc. Shouguang magnetic anomaly is the emphasis target section in prospecting in the future.