THE STRATIGRAPHIC DISTRIBUTION OF FUSULINIDS IN THE UPPER CARBONIFEROUS TAIYUAN FORMATION IN SOUTHWESTERN SHANXI

The Xiangning and Hejin areas in the southernmost part of the Hedong coal field of Shanxi are stratigradhically situated in the southeastern corner of the Shanxi-Gansu-Ningxia stratigraphic region, of the North China stratigraphic province. The fusuiinids from the Taiyuan Formation southwestern Shanxi include 96 species, subspecies and varieties of 15 genera, characterized bv the presence of Pseudoschwagerininae. The rapid evolution of these fusulinids permits a hiostratigraphic zonation; thus 1 fusulinid zone and 5 subzones are established in descending order as follows: Pseudoschwagerina（s. 1. ） Zone 5. Robustoschwagerina schellwieni pamirica Subzone 4. Pseudofusslina parajaponica Subzone 3. Sphaeroschwagerina glomerosa Subzone 2. Dunbarinella subnathorsti Subzone 1. Pseudofusulina pseudovul garis-Rugosofusulina valida Subzone. The correlatinn of the fusulinid zone and subzones in the Taiyuan Formation in southwestern Shanxi with their equivalent fusulinid-bearing strata in other regions are given in Table 2.