渔塘铅锌矿田“贫中找富”是如何取得重大突破的?

HOW AN IMPORTANT BREAKTHROUGH IN FINDING RICH FROM POOR OBTAINED IN YUTANG LEAD-ZINC OREFIELD?

渔塘铅锌矿田,面积100km^2以上,1986年以前间断勘查三十多年,只探明铅锌金属量20000t。1986年后开展科学研究,发现富矿体有两种类型,产于原地藻灰岩中者集中而稳定,属Ⅰ—Ⅱ勘探类型;产于礁间沉积物中者分散且稳定性差,属Ⅱ—Ⅳ勘探类型。以此认识布置钻探工作,取得了在贫矿中寻找富矿的重大进展,探明铅锌金属量500000t的富矿体。

The Yutang lead-zinc orefield in the northern part of Xianqian lead-zinc ore zone, covering an area of more than 100km^2, was considered to be Mississippi valley-type ore deposit by Meng Xianmin et al based on an investigation in 1955, and it is of great prospect. Since then, many methods were applied to locate rich orebodies, but no important advances have been achieved in the past thirty years, only 20000T lead and zinc metal reserve being demonstrated. Since 1986, a detailed lithofacies study was launched and it is found that there are two kinds of rich orebody: the one occurred in autochthonous algal limestone is concentrated and stable, belonging to exploratory group Ⅰ--Ⅱ; and the one occurred in the sediments between reefs scatters and is unstable, belonging to exploratory group Ⅱ--Ⅳ. The exploratory project based on the above understanding has resulted in a great advance in finding rich orebodies from the poor ore zone, and some rich orebodies with total lead and zinc reserve reaching 500000T are demonstrated.