摘要
本文对苏皖沉积型凹凸棒石粘土矿床形成时的沉积环境特征、水介质的ｐＨ值、氧化还原条件、温度及盐度进行了讨论。研究表明凹凸棒石粘土矿床形成于碱性、还原、低盐度的浅水湖相环境。
The Sedimentary attapulgite clay deposit on the boder of Jiangsu and Anhui Provinces is an important producing area of attapulgite clay in China. Ore-bearing Series is a set of sedimentary clastic rocks of shallow lake. The sedimentary medium features are as follows: 1) Various attapulgite clays have different pH values, all of them are formed in an alkalic condition; 2) According to the features and Ceanom calculated values of variant clays, the attapulgite clays are formed in a reducing condition, and part of montmorillonite clay is formed in a weak oxido-condition; 3) On the basis of stable isotopic compositions of opal and dolomite, opal-forming temperature is 71℃ 81℃ and dolomite-forming temperature is 29℃ 74℃.These features with other geochemical characteristics infered that the forming temperature of attapulgite clays is higher than the normal sedimentary temperature; 4) MgO/Al 2O 3 Sr/Ba Rb/K ratios of variant attapulgite clays showed that the forming salinity of dolomite attapulgite clay, siliceous attapulgite clay and attapulgite clay is higher than that of montmorillonite clay. To sum up, the study indicated that under the conditions of alkalic, reducing conditions and low salinity of water medium, attapulgite clay deposits could be formed in a shallow lacustrine basin. The hydrothermal solution being related to volcanic action is of certain significance to mineralization of attapulgite clay deposits.
出处
《沉积学报》
CAS
CSCD
北大核心
1996年第4期141-147,共7页
Acta Sedimentologica Sinica
