山东省齐河地区接触交代型铁矿成矿要素耦合分析

鲁西地区齐河地区近年来在铁矿勘查过程中发现了多个接触交代型铁矿,该区铁矿经勘查显示有集中分布、厚度大、品位高、埋深大的特点。研究区大张、李屯和潘店地区物探异常查证工作表明铁矿形态多样,呈层状、似层状、囊状、脉状等。该区铁矿体具有明显的“地层、侵入岩和构造”控矿特征;在铁矿体赋存位置方面,地层控矿表现为部分铁矿体赋存于奥陶纪（石炭纪、二叠纪）地层中、侵入岩控矿表现为部分铁矿产于闪长岩体中,接触带控矿则表现为地层和岩体间接触带是主要铁矿赋存地段。矿床成因研究表明：在燕山晚期研究区发生了大规模的岩浆活动,在深源岩浆向上侵位过程中不断演化分异,形成了闪长质岩浆,在与奥陶纪灰岩接触过程中发生了复杂的物理化学反应,闪长质岩浆析出大量铁质成分,形成含铁富矿热液,并在有利赋矿部位形成铁矿体。研究区接触交代型铁矿的形成与保存是中生代区域性构造—岩浆—热液活动事件和区内地层、岩浆及构造等各种成矿要素有机耦合的结果,该区铁矿具有十分重要的勘查研究和社会经济价值。

Study on the coupling of ore-forming factors of contact metasomatic iron ore in Qihe area, Shandong Province

In recent years, several contact metasomatic iron deposits have been found in Qihe area of western Shandong province in the process of iron ore exploration, which is characterized by "concentrated distribution, large thickness, high grade and deep burial". The investigation and verification of geophysical anomalies in Dazhang, Litun and Pandian areas in the study area shows the iron ores in this area have various forms, such as layered, stratoid, saccular, vein, etc. The iron ore body in this area has obvious ore control characteristics of "stratum, intrusive rock and structure"; in terms of the occurrence location of iron ore body, the ore control of stratum is shown as that part of iron ore body occurs in the Ordovician (Carboniferous, Permian) stratum, the ore control of intrusive rock is shown as that part of iron ore occurs in diorite, and the ore control of contact zone is shown as that the indirect contact zone of stratum and rock body is the main ore occurrence area. The study on the genesis of the deposits shows that large-scale magmatic activities occurred in the late Yanshanian in the study area, which evolved and differentiated during the upwelling process of the deep source magma and formed the diorite magma. During the contact process with the Ordovician limestone, complex physicochemical reactions took place. The diorite magma separated out a large number of iron components, formed the iron bearing and rich ore hydrothermal fluid, and formed in the favorable ore bearing parts forming iron ore body. The formation and preservation of contact metasomatic iron ore in the study area is the result of the Mesozoic regional tectonic magmatic hydrothermal activity event and the organic coupling of various metallogenic and ore controlling factors such as strata, magma and structure in the area. The iron ore in this area has very important exploration research and social and economic value.