摘要
云南兰坪—思茅盆地是我国重要的成钾盆地,对盆地内勐野井组层位的泥砾岩段(成盐阶段)粘土样品进行XRD分析;同时对滇中楚雄盆地的相同层位(元永井组)粘土样品进行了XRD对比分析。实验结果表明,兰坪—思茅盆地内的样品中粘土矿物组合为伊利石+绿泥石,表明了在成盐阶段较为干旱的古气候条件与较高的古盐度;而楚雄盆地一平浪样品中除伊利石+绿泥石组合外,还含有伊利石/蒙皂石混层矿物,反映了当时的古气候条件与兰坪—思茅盆地相比较为湿润。通过计算样品中各种粘土矿物的相对含量,指出兰坪—思茅盆地成盐阶段更晚,成盐作用更强。结合前人的研究成果探讨了兰坪—思茅盆地的成盐环境,指出盆地南部卤水较北部浓缩程度更高,南部成盐条件优于北部。
Yunnan Lanping-simao basin is an important basin with K salt deposition in China. The clay minerals samples exist in Paleocene Mengyejing formation of muddy gravel phase（ salt-forming epoch） in Lanping-simao basin including the samples of the same strata （ Yuanyongjing Formation） in Chuxiong ba- sin of central Yunnan are experimented by the method of XRD. The experiment results show that the dominant assemblage of clay minerals in Lanping-simao basin are iUite and chlorite, and indicates that the dry paleoclimate and high paleosalinity in salt-forming epoch; but in Chuxiong basin, illite and chlo- rite, illite/smectite mixed-layer minerals are coexisting, it reflects the wetter paleoclimate than Lanping- simao basin. It indicates that the salt-forming epoch in Lanping-simao basin is later and the salification in Lanping-siman basin is stronger by calculating the relatively composition of the clay minerals. Based on previous researches, the tentative discussion of salt-forming environment in Lanping-Simao basin sugges- ted that the overall degree of brine concentration in the southern part of the basin is higher than the north- ern, and the salt ore-forming environment in the southern is better than the northern too.
出处
《盐湖研究》
CSCD
2011年第4期8-14,共7页
Journal of Salt Lake Research
基金
中国科学院知识创新工程重要方向项目(KZCX2-YW-344)
关键词
兰坪-思茅盆地
粘土矿物
XRD
成盐阶段
成盐环境
Lanping-Simao basin
Clay minerals
XRD
Salt-forming epoch
Salt-forming environment
