Multiple stratigraphic division and correlation of the Permo Carboniferous of Yuzhou of Henan and Taiyuan of Shanxi

The Benxi, Taiyuan and Shanxi formations of Yuzhou, Henan,are lithologically similar to and thinner than those of Taiyuan, Shanxi. The Shihezi Formation of Yuzhou is different from that of Taiyuan in lithology and thickness. The coal beds of Taiyuan are thicker and lower in horizon, while the coal beds of Yuzhou are thinner and higher. The Benxi, Taiyuan and Shanxi formations are diachronous southward,indicating southward transgression. The Shihezi Formation is diachronous northward, implying northward back flooding of sea water. From bottom to top the depositional vironment evolved from the epicontinental through the delta to the continental sedimentary system, and shifted southward, reflecting that the paleogeographic framework was generally characterized by the distribution of land in the north and sea in the south.