THE DISTRIBUTION LAW AND CONTROLLING FACTORS OF THE RICH PHOSPHORITE ORE IN ANNING PHOSPHOROUS DEPOSIT, YUNNAN PROVINCE

The Anning phosphorous deposit is located 40 km to the southwest of Kunming City, Yunnan Province. The rich ores of phosphorite occur in the upper bed of Zhongyicun member, Meishucun formation, Cambrian. The rich phosphorite includes primary rich ore and weathered rich ore. The distribution of the rich phosphorite varies in different ore blocks. The forming of the primary rich ore is controlled by depositing environment and sedimentation; while that of the weathered rich ore, by structures, capping beds and the characters of ore beds.