地质学报Issue(11)：2093-2104,12.
云南思茅盆地勐野井组碎屑岩矿物学、地球化学特征及古盐湖沉积环境演化
Mineralogical and Geochemical Characteristics of Detrital Rocks in the Mengyejing Formation and Evolution of the Sedimentary Environment of Paleolake in Simao Basin,Yunnan Province
摘要
Abstract
Clay mineralogy and geochemistry of detrital sediment samples collected in a core of the Mengyejing Potash salt mining of Simao basin,Yunnan were used to evaluate the provenance and sedimentary environment evolution of paleolake.The clay mineral assemblages,La/Th-Hf,La/Sc-Th/Co,La-Th-Sc diagrams and values of Cr/Th,Al2 O3/TiO2 indicate that the provenance of the detrital sediment is mainly granodiorites.And the major element results indicate that the formation of clay minerals is accompanied by leaching of Ca and Na first and enrichment of K and Mg.Fe and Mn,is deplete because of the limitations provenance.Combined with the formation conditions of clay minerals,we suggest that the paleolake experienced a variable paleoclimate evolution process which characterized by warm and wet to warm and dry (the stage of salt-forming and sylvite-forming )to warm and wet (the desalination stage).The hypersaline environment and burial diagenesis affected the clay mineral assemblages significantly, documented by the widespread occurrence of illitization and chloritization in core samples.Thus,the clay mineral assemblages of illite + chlorite, combined with the abundance of Mg-rich chlorite and the abnormally high value of MgO of detrital sediments at the corresponding stage are indictive of the evolution of salt-forming and sylvite-forming stage.关键词
晚白垩世/碎屑岩/粘土矿物/地球化学/物源/成盐成钾/云南思茅盆地Key words
the Late Cretaceous/detrital rocks/clay minerals/geochemical/provenance/salt-forming and sylvite-forming/the Simao basin of Yunnan引用本文复制引用
苗卫良,马海州,张西营,石海岩,李永寿,容志明..云南思茅盆地勐野井组碎屑岩矿物学、地球化学特征及古盐湖沉积环境演化[J].地质学报,2015,(11):2093-2104,12.基金项目
本文为国家“973”计划项目第四课题“兰坪－思茅新生代残留盆地成钾条件、机理和后期演化”（编号2011CB403004）和国家自然科学基金青年基金项目（编号41303029）资助的成果。 （）
