Geological Characteristics, Genesis And Predication Of Sedimentary-type Bauxite Deposit In The Taiping District, Pingguo, Guangxi

The Pingguo bauxite ore field is the producing area of bauxite resources for the Guangxi Branch Company of the Aluminum Corporation of China. For a long time, the cumulate-type bauxite has been the mining object. The continuous expanding of producing ability of the company and the quick decreasing of remained cumulate-type bauxite resources make the task of searching for new bauxite resources to be extremely urgent. Under this kind of situation, exploring the sedimentary-type bauxite becomes an inevitable choice for solving problems, and so the Taiping mine district is choosed as the exploring and reserching area for the huge bauxite resource potential here.Established in the Taiping district in Pingguo ore field, this paper analysed the geological ore-forming conditions, basically found out the geological characteristics of deposits, discussed the genesis of deposits, summed up the ore-controlling factors and ore-searching indicators, through field geology surveys, rocks and minerals appraisals, exploration works, as well as indoor comprehensive studies. Based on the above conclusions, the predication of deposits was carried out and the favorable ore-forming targets were given. In order to validate the prediction results, some exploration works were implemented and then the resource reserves was calculated out.The characteristics of the strata, the bauxite-bearing sequences and the tectonics in the Taiping mine district have been found out. The district is located on the Taiping syncline between the Xingning anticlinorium and the Nadou anticline, striking along NW-SE in the whole. Two groups of faults, striking in NE and NW, are developed in this area. The bauxite-bearing sequences are located on the NE flank of the Taiping syncline, strikes in near NW-SE and trends to near SW, quite unbent along the strike direction.The main ore minerals of sedimentary-type bauxite are diaspores, bayerites and alumogels. The ore structures are mainly grain structure, crystal structure, mud structure and so on and the ore constructions are mainly oolite construction, compact nubby construction, directional construction and so on. But the bayerite has xenomorphic grain structure and nubby construction. The bauxite can be classified as oolite bauxite, fabaceous bauxite and compact nubby bauxite according to the structures and constructions. As for ore grade,Ⅲupwards accounts for 42.53%,Ⅵupwards 42.53% and out grade 22.99%.The genesis type of sedimentary bauxite in Taiping district is littoral sedimentary bauxite. The ore-forming materials are derived from nether limestone of the Maokou formation. The continental surface geological process is the general factor of bauxite forming. The steady geotectonic environment is the foundation of the enrichment of aluminium elements. The ancient topography and physiognomy and the tectonic evolution restrict the forming and distribution of bauxite. The regional synclines, the flint-limestone and coal beds and the natural outcrops of the sedimentray-type bauxite are important ore-searching indicators. The sedimentray-type bauxite-bearing strata are in the bottom of the Heshan formation. The regional anticlines and synclines play important roles in controlling the natural bauxite.The deep part of the NE flank of the Taiping syncline in the southwest of natural bauxite outcrops is the exploration target of sedimentary-type bauxite in the Taiping district. The ore-forming prediction results are validated by exploration works. Eight self-governed sedimentary-type bauxite bodies are delimited and the controlted resource reserves (333) is totally 1774.0303×104 tons, which can prolong the serving time 4～5 years.