Sedimentary characteristics and mineralization of the phosphorite deposits in the Leibo ore field, Sichuan

The phosphorite deposits in the Leibo ore field, Sichuan are interpreted to be the Kunyang-type marine sedimentary phosphorite deposits, and hosted to the strata of the Lower Cambrian (early Meishucunian) Maidiping Formation. The integration of lithology and sedimentary facies analysis of the Maidiping Formation shows that the Leibo ore field roughly represents the vertical transgression-regression-transgression sedimentary associations in the carbonate tidal-flat sedimentary environment during the early Meishucunian. The sedimentary facies display zonal distribution, and there is a nearly positive correlation between the thickness of the phosphorite beds and those of the strata. The sedimentary facies distribution and palaeogeographic environments also have an important effect on the physical enrichment and mineralization of phosphorous particles. The subtidal high-energy zone is believed to be the most favourable zone for the accumulation and mineralization of phosphorite ores, and thus may be delineated as the key zone for future exploration of phosphorite deposits in the Leibo ore field.