兰坪-思茅盆地勐野井组钾盐矿床成矿构造背景

Ore-forming tectonic setting of the Mengyejing Formation potash deposits in Lanping-Simao Basin

中文关键词:  兰坪—思茅盆地  钾盐矿床  成矿背景

英文关键词:Lanping-Simao Basin  sylvite deposit  Ore-forming tectonic setting

中文摘要:

      兰坪-思茅盆地为我国境内唯一发现古钾盐沉积的盆地。本文对云南兰坪—思茅盆地钾盐成矿背景做了总结与分析。指出中生代以来盆地经历了陆内裂谷的形成到消亡、侏罗世箕状断陷盆地发育阶段、早白垩纪双断式断陷盆地发育阶段、早白垩晚期干化成盐和后期挤压走滑几个阶段。在此基础上通过盐系地层沉积特征的分析,揭示了盆地在成盐期(早白垩晚期)构造活动强烈,由统一的湖盆解体为多个次级成盐盆地,盐类资源的沉积应该分属不同的沉积序列这样一种认识。对该盆地成盐期构造背景的分析对于认识该区蒸发岩矿床成矿特征和成矿机理具有重要的参考意义。

英文摘要:

      Lanping-Simao basin is the only basin with ancient sylvite deposit in China. This paper made a summary and analysis for the tectonic background of salt-forming and sylvite-forming in Lanping-Simao basin. And the result show that the development of Mesozoic basin has gone through the formed to death of intracontinental rift, the development stage of the Jurassic half-graben depression basin, the development stage of the Early Cretaceous double downfaulted basin, the salinization and compressional strike-slip stages of the late Early Cretaceous, respectively. On this basis, through the analysis of sedimentary characteristics of salt-bearing strata, we recognize that the intense tectonic movement developed during salt-forming stage (late Early Cretaceous) in Lanping-Simao basin, multiple secondary salt-forming basins formed through the disintegration of the unified paleolake, and deposited salts resources should belong to different depositional sequences. There is important implication that investigate the tectonic setting during salt-forming of Lanping-Simao basin, understanding the characteristics of evaporite deposits and ore-forming mechanism.