湖北省鹤峰磷矿整装勘查区地质特征及找矿远景

Geological characteristics and ore-prospecting potential of the integrated exploration area of Hefeng phosphate mine,Hubei Province

鹤峰磷矿整装勘查区位于鹤峰-东山峰磷矿带(Ⅳ级)-鹤峰磷矿田(Ⅴ级)的西部,属东山峰磷矿西段部分,为沉积型层控矿床。勘查区内磷矿分布在下震旦统陡山沱组第三段(Z1d3)中,分为上、下两个含磷层,上含磷层为区内主要含磷层,也为以往寻找风化磷矿的目标层。下震旦统陡山沱组第二段(Z1d2)碳质泥岩为含磷岩系的直接底板。根据赋矿层位及岩性特征,东山峰磷矿的上、下含磷层与鄂西磷矿的Ph3、Ph2比对较为合适。含磷岩系可划分出四个较明显的沉积旋回。含磷岩系中的Ⅰ、Ⅱ、Ⅲ、Ⅳ矿体赋存部位均处于各个旋回的后期,沉积环境主要为潮间砂坪-砂泥坪相。勘查区磷块岩磷质的直接来源主要来自富磷上升洋流,而陡山沱期的生物繁盛为磷质的进一步聚集和沉积提供了条件。通过探槽及钻探工程控制,Ph3磷矿层在区内非常稳定,向NW方向稳定延伸,深部具有较好的找矿前景。在前期工作的基础上划分出4个成矿远景区,均为中低品位的沉积型磷矿。

The integrated exploration area of Hefeng phosphate mine is located in the western part of the HefengDongshanfeng phosphorus ore belt(grade IV)-Hefeng phosphorus ore field(grade V),which belongs to the western section of the Dongshanfeng phosphorus deposit,it is a sedimentary strata-controlled deposit.Phosphorus ore in the exploration area is distributed in the third section of Doushantuo Formation of Lower Sinian System(Z1d3),divided into upper and lower phosphorus-bearing layers.The upper phosphorus-bearing layer is the main phosphorus-bearing layer in the area,is also the target layer for the search of weathered phosphorus ore in the past.The carbonaceous mudstone in the second section(Z1d2)of Doushantuo formation is the direct floor of the phosphorus-bearing rock series.According to the ore-bearing layer and lithological characteristics,the upper and lower phosphorus-bearing layers of Dongshanfeng phosphorus deposit are more appropriately compared with the Ph3 and Ph2 of the western Hubei phosphorus deposit.The phosphorus-bearing rock series can be divided into four relatively obvious sedimentary gyrations.The occurrence positions of the I,II,III,and IV ore bodies in the phosphorus-bearing rock series are all in the later stage of each gyration,and the sedimentary environment is mainly the intertidal sandflat-sandy mudflat facies.The direct source of phosphorus in the phosphorite of the exploration area mainly comes from the upward movement of the rich phosphorus ocean current,and the prosperous organisms during the Doushantuo period provided conditions for the further aggregation and deposition of phosphorus.Through the control of trenching and drilling projects,the Ph3 phosphorite layer in this area is very stable,extending stably in the northwest direction,and has good prospecting prospects in the deep part.Based on the previous work,four ore-forming prospective areas have been defined,all of which are medium and low grade sedimentary phosphorite.