The Geological Features And Its Sedimentary Environment Analysis Of The Yiliang-Huaning Phosphate Deposit Belt

In this paper, we systemically summarized the stratigraphic age of the ore-bearing strata and its spatial distribution of the Yiliang-Huaning phosphate metallogenic belt, Eastern Yunnan, the research area, by the means of field geological survey, profile measurement, exploration engineering logging and systemic sampling combined with the analysis indoor test. The phosphate rock in this metallogenic belt is mostly middle-low grade and a little rich ore (Grade one). As contrast to the phosphorite around Dianchi Lake, the geological research level of this metallogenic belt is relatively lower. So it is significant to better understand of the special and temporal distribution, ore body characteristic, ore type and sedimentary environment of the middle-low grade phosphate rock that the geological characteristic of the phosphate rock in this region was systemically summarized. In addition, with the continuing consuming about the rich phosphate rock, it is necessary to make full use of the middle-low phosphate rock and make a deeper research on the phosphate rock in this metallogenic belt.The spatial distribution of the ore-bearing strata and the typical ore body were the focal point of the study. After this study, author summarized the distribution of the phosphate rock and the forming conditions. The studying gets some conclusions as follows:After the study of the spatial and temporal distribution of the phosphate layer, it is concluded that the phosphorus in this area is marine sedimentary type and the ore-bearing strata is the Yuhucun formation, lower Cambrian. The phosphorus layer was a NNE band in the spatial form. Form north to south, the thickness of the phosphate rocks has the character:both end thin, the middle thick. The stricter of ore-bearing strata is mainly "single layer structure" with less "double layer structure".Through the study of two typical phosphate ore body, it is obtained that they have some common characteristic:â‘ The phosphates both occur in the lower Cambrian, and no wear layer phenomenon.â‘¡The grade of phosphate rocks exposed on the surface is relatively high due to the weathering and leaching.â‘¢The phosphate deposits are all along the zone of low notch groove of the edge of the sedimentary basin.The sedimentary environment of the phosphate is also discussed in this paper. Through the analysis of three typical deposition sections, we come to the conclusion that phosphate formed in the intertidal sand flat environment. In the frequent tidal activity zone, the formal depositional gelatinous phosphate rocks were dehydrated and contracted, as intermittently exposed on the surface. Then the phosphate rocks were scoured by the tide water, the gelatinous phosphate rocks were broken into different sizes and particles. Then the back tide brought these particles back to the intertidal edge and deposited. The repeatedly process of broken and scoured is provided for the source of the phosphate deposits in the intertidal shoreline.