Sequence Stratigraphy Of The Doushantuo Formation And Mineralization Of Manganese In Chengkou Area, Chongqing City

Manganese as an important mineral resources in our country, plays an extremely important role in the national economy. Manganese is an essential raw material for the steel industry. Chongqing manganese resources, mainly in the port city of Xiushan and regions, with the rapid development of the two resource processing industries, manganese industry has become a pillar industry in the economic development of the two counties. With the rapid development of the local economy, manganese ore resource consumption has increased, the amount of recoverable resources continue to reduce gradually decreases and the old mining capacity of the existing ore resources are difficult to meet the market demand, production and demand contradictions have become increasingly prominent. To meet the needs of local economic development of mineral resources, on the one hand the need to improve the level of deep processing of manganese; on the other hand, more importantly, innovative methods of manganese ore, prospecting ideas, focus on strengthening the Chongqing Manganese Ore condition, ore control law research, advanced theoretical guidance for manganese ore exploration, especially deep ore prospecting.Manganese ore in Chengkou area mainly concentrated in the upper part of Doushantuo formation, stratabound characteristics is obvious. However, further study for this ore deposit formation, especially with lithofacies paleogeography, sedimentary formation, structural ore-control is less. In this paper, we take a typical ore area of Chengkou for the study area object, by means of field geological reconnaissance, profile measured, core observation, as well as other means of field geology, in order to assign bit steep mountain ledge lump group for the study, and incorporates profiles information we collected, focusing on the sedimentary sequence, sequence stratigraphy and sequence stratigraphic framework of the Doushantuo formation. Based on this further integration of geochemical characteristics to explore its manganese ore-controlling mechanism. Achieve the following results as follows:1) By studying the field outcrop sequence stratigraphy, we can identify four typical interfaces:parallel unconformity surface, exposed surface, lithological and lithofacies turnaround surface, formation overlay structure transitional surface. Comprehensive studies have shown that the bottom-up can be divided six mid-sequence-three depositional sequences unit ZOS0-ZOS5; two long-term sequences ZSS1,ZSS2.2) Due to the differences of lithology, structural features etc., there is a big changes in the vertical distributionelement of geochemical characteristics; light rare enrichment evident in total relatively heavy rare earth, Ce, Eu show significant negative anomalies; trace element results indicate Doushantuo formation belongs one kind of oxygen-depleted-hypoxic environment, and the formation of deposits company with hydrothermal injection.3) When sea water rises to a maximum level, the upper portion Doushantuo formation formed a condensed layer with typical characteristics manganese phosphate layer during the maximum flooding. That is, phosphorus manganese layer in the Doushantuo formation.t. Although the top of Chengkou Doushantuo formation region is endowed phosphorus manganese seam position, but due to differences in terrain, different sections of the manganese layers is vary, some areas even do not have the output layer of manganese, from the north west in space south east have gradually increased.