LU Liu-yan1, CHEN Ren1, YU Ning2, TIAN Mao-jun3, QIAO Wei-tao1, HU Xin-rui1, YUE Long1, ZHOU Wu1
(1. Guizhou Geological Survey, Guiyang 550081, China;
2. College of Resources and Environmental Engineering, Guizhou Institute of Technology, Guiyang 550003, China;
3. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China)
Abstract: The Kaiyang area in the Central Guizhou is located in the paleo-uplift area with relatively high paleotopography. The carbonate basement provided the materials and the paleokarst depression provided sedimentary space for the bauxite-bearing rocks series of Early Carboniferous Jiujialu Formation, . In order to find out the reason why there is no medium-sized and large-sized bauxite deposits in the Kaiyang-Weng'an area in the Central Guizhou Early Carboniferous bauxite metallogenic belt, The authors operated surveys of exploratory trenches and sections of the Carboniferous Jiujialu Formation and fetched samples to do the geochemical analysis based on the investigation of regional geology and mineral resources. The geochemical analyses show that samples of the section of bauxite-bearing rocks series have Sr/ Ba values of 0.22-0.55 with the average of 0.33, t Sr/Cu values of 2.27-5.85 in the lower part and 24.78-67.74 in the middle and upper parts of the section, Th/U values of 2.99-4.97 with the average of 3.9, and V/(V+Ni) values of 0.85-0.99. These show that the paleoclimate of Datang period in the Kaiyang area was hot and dry, the bauxite-bearing rock series were formed in the reduced continental sedimentary environment by the uncompletely weathered materials with complicated components. It is believed that the paleokarst landform of carbonate rocks in the Kaiyang area controlled the development degree, size and depositional environment of the bauxite-bearing rock series. Meanwhile, the Early Carboniferous closed and reduced lake sedimentary environment and hot and dry paleoclimate conditions in the Kaiyang area restricted the mineralization, enrichment and formation of bauxite deposits.
Keywords: Kaiyang area in the central Guizhou; Early Carboniferous; bauxite; lithofacies paleogeography; geochemistry
ACTA MINERALOGICA SINICA Vol. 41, No.4/5, 2021, page 509-519