鲁西地区“杨庄式”铁矿的命名与预测模型

Proposal of “Yangzhuang Type” Iron Ore and Prediction Model in Luxi Area

在鲁西地区沂沭断裂带中发育有BIF型铁矿,其赋矿地层为新太古代泰山岩群柳杭组,铁矿体呈包体状残留于新太古代侵入岩中;但由于铁矿床规模较小,前人一直未将之作为一个独立矿床式进行分类。通过对该区铁矿进行研究认为,区内该类型铁矿含矿建造独特、赋矿环境迥异而具有代表性,以其品位较高、埋藏较浅、易于开采、具有较好的经济价值和勘查前景,且与鲁西地区已有铁矿类型具有不同的成矿地质条件为特征,故将该类型铁矿命名为"杨庄式"铁矿,使鲁西地区赋存的BIF型铁矿增加到三个矿床类型,即"苍峄式"铁矿、"杨庄式"铁矿和"济宁式"铁矿。区内找矿模型主要是以地质和地球物理模型为主,以其磁场特征与含矿建造特征及其矿体规模形态高度吻合为表现形式。对区内该类型铁矿预测模型(包括区域成矿环境、成矿特征、地球物理特征等)和找矿标志进行了研究和总结,区域成矿预测工作显示在崔岜峪铁矿远景区、磨山河铁矿远景区、北躲庄铁矿远景区和酿泉官庄铁矿远景区具有"杨庄式"铁矿找矿前景,通过对其预测模型和找矿标志的综合利用可对相关地区铁矿开展调查评价工作。

BIF type iron ore deposits have been discovered in the Yishu fault belt in Luxi area,and its ore bearing strata is the Liuhang Formation of Neo Archean Taishan Group. The iron ore bodies as stratigraphic inclusions residue in the Neo Archean intrusive rocks. Because of its small size,in the past,the iron ore has not been classified as an independent deposit type. According to the study of the iron ore in this area,it is thought that in the typical ore-bearing formation with its special occurrence environment has strong representativeness,shallow burial of iron ore in the region,easy exploitation,having better economic value and exploration prospect. With the special ore-forming geological conditions,this type iron ore is different from other iron ore types having been found in Luxi region. Therefore,the iron ore type is named "Yangzhuang type"iron ore and it is also in line with the actual geological characteristics. So far,three BIF types iron ore in the Luxi area are "Cangyi type"iron ore,"Yangzhuang type"iron ore,and "Jining type"iron ore. The prospecting model in the area is mainly based on the geological and geophysical characteristics,besides the magnetic field characteristics and the size and shape of the characteristics of the ore bearing formation and the ore bodies are highly consistent. In addition,the prediction model( including the regional metallogenic environment,metallogenic characteristics,geophysical characteristics,etc) and the ore-prospecting criteria of this type of iron ore were investigated and summarized. Regional metallogenic prognosis indicates that Cuibayu iron ore prospecting area,Moshanhe iron ore prospecting area,Beiduozhuang iron ore prospecting area and Niangquanguanzhuang iron ore prospecting area have prospecting potential of the "Yangzhuang type"iron ore. The investigation and evaluation in relevant regions is carried out by comprehensive utilization of the prediction model and prospecting marks of this type of iron ore.