AGE OF THE LONGYIN FORMATION IN SOUTHWEST GUIZHOU PROVINCE——A DISCUSSION ABOUT THE CORRELATION OF THE LOWER PERMIAN BETWEEN SOUTH CHINA AND THE URAL OF USSR

The Permian Artinskian age of the Longyin Formation is indicated by the appearanceof the ammonoid Popanoceras fauna at its lowermost part. The upper Maping Formationin South China should include all the Sakmarin deposit at least.