The Qinglongshao and Dashuizha Continental facies phosphorite

Key words: 
• continental facies phosphorite /
• " /
• Dashuizha type"

Abstract: The Dashuizha phosphorus mine is located in a place where Shifang and Mianzhu of Sichuan Province meet and where the brecciated phosphorus ore is in lower part of the original "Shifang type" one. The original "Shifang type" phosphorus ore was mainly composed of the palingenetic marine phosphorite of Middle and Late Devonian Epoch including upper ore beds of goyazite (originally called sulfur goyazite ore ) and lower brecciated phosphorite. It was found by recent studies of the authors that the upper mineral bed of goyazite belongs to the marine facies phosphorite of Middle Devonian Epoch while the lower part brecciated phosphorite to the continental facies one whose geological characteristics are very similar to the Qinglongshao phosphorite ore of Yunnan Province. The phosphorus ore bed bearing goyazite and kaolinite were found to be in onlap unconfornity in the apical plate of the Qinglongshao brecciated phosphorite, which indicates the stratigraphic pattern and bed sequence of the Qinglongshao phosphorus ore are very similar to those of the Dashuizha ore. The present study has confirmed that both the brecciated phosphorite systems are continental facies and that the Meishucun phosphorite of the Lower Cambrian was weathered, accumulated, consolidated and so on for a long time from the Late Cambrian to Late Devonian. Thus, the Qinglongshao and Dashuizha phosphorus ores could be called the "Dashuizha type" phosphorus ore.