垫江盐盆岩盐矿地质特征及资源潜力

Geological characteristics and resource potential of the salt rock,in Dianjiang salt basin

垫江盐盆位于四川盆地东部,早中三叠世嘉陵江、雷口坡时期广泛接受蒸发型盐类沉积,在长寿-垫江-带形成了多期次岩盐沉积。通过对区内岩盐、油气钻井含盐系对比分析发现,垫江盐盆具有3个成盐期:下三叠统嘉陵江组四段二亚段(T1J^4-2)、四段四亚段(T1J^4-4)和中三叠统雷口坡组一段一亚段(T2l^1-1),岩盐直接顶底板为硬石膏岩或杂卤石,从T1J^4-2至T2l^1-1,岩盐沉积具有层数变多、厚度变薄、向北东方向缩小的趋势。另外,通过DTM分析编制的岩盐沉积等厚线图,为垫江盐盆岩盐资源潜力估算提供了可靠的依据,据估算垫江盐盆岩盐远景资源量约300亿t,其中未受构造影响区块资源量约230亿t。

The Dianjiang Salt Basin belongs to the eastern part of the Sichuan Basin.During the Lower-Middle Triassic Jialing and Leikoupo period,it was widely accepted as evaporative salt deposits,and multi-stage sub-salt deposits were formed in the Changshou-Dajiang area.Through the comparative analysis of rock salt and oil and gas drilling salt system in the area,it is found that the Dianjiang salt basin has three salt formation periods:T1 j^4-2,T1 j^4-4 and T2 l^1-1.The direct top and bottom of the rock salt is anhydrite or polyhalite.From T1 j^4-2 to T2 l^1-1,the number of salt layers is more,the thickness becomes thinner and tends to shrink toward the northeast.In addition,the thick-line maps of rock salt deposits prepared by DTM analysis provide a reliable basis for the estimation of the salt resources of the Dianjiang salt basin.It is estimated that the prospective resources of the Dianjiang salt basin rock salt is about 30 billion tons,of which the unaffected area is not affected.The block resource is about 23 billion tons,and the resource potential is large.