西藏主要含煤岩系及其成煤环境初探

Brief study on the coal series and its sedimentary characters in Tibet

西藏煤系分布广泛,本文通过对西藏煤系的初步研究,主要从煤系地层、岩石组成以及煤系沉积特点三个方面对马查拉煤系、妥坝煤系、土门煤系、多尼煤系四个主要的西藏煤系进行初步探讨。认为马查拉煤系的沉积环境属浅海-海陆交互相沉积,妥坝煤系不仅具有海陆过渡相之滨岸三角洲带-碎屑潮坪-潮坪泻湖相沉积,还具有滨岸碳酸盐潮坪-碳酸盐台地的滨海-浅海清水沉积的特征,土门煤系则是下部以浅海相沉积为主,中部以海陆交互相沉积为主,上部以陆相沉积为主,多尼煤系则是滨海与海陆过渡相沉积。

Coal is widely distributed in Tibet. This paper mainly discuss the characteristic of Machala, Tuoba, Tumen and Duoni coal-bearing strata in Tibet through coal-bearing strata feature, petrology and sedimentary fea- ture aspects. The result shows that： Machala coal measures were formed in shallow marine-paralic evironment; Tuba coal measure not only has the sedimentary of transitional facies in Delta coastal-Tidal debris-Tidal lagoon facies, but also has the sedimentary characters in carbonate tidal coastal and coastal of carbonate platform- shal- low sea evironment; lower part of the Tumen coal measure is dominated by the shallow marine deposit, the middle is dominated by the sedimentary of paralic faces, while upper part of it is dominated by terrestrial deposit; Duoni coal measure is mainly sedimentary in coastal and transitional environment.