Stratigraphic Significance of the Iugs Geological Heritage Site Permian Vegatational Pompeii

The Wuda Tuff Flora, yielded from the Taiyuan Formation of the Wuda Coalfield, Inner Mongolia, has been called Permian vegetational Pompeii, with regard to the geologic and taphonomic similarities to the world-famous Italian UNESCO World Heritage Site of the Roman city of Pompeii. It represents a peat-forming forest preserved in situ by a 298.34 ± 0.09 Ma volcanic ash fall, well known as a plant fossil lagerstätte, snapshooting a glimpse to the late Paleozoic peat-forming forest, offering an unrivaled chance to detect vegetational community ecology based on actual reconstruction. With respects to the great scientific significance, the Wuda Tuff Flora has been selected as one of the Second 100 IUGS Geological Heritage Sites. So far, some areas of over 10, 000 square meters quantitative taphonomical investigation of forest ecology has been conducted, showing over 50 taxa of seven groups of plants make up this peat-forming vegetation including lycopsids, sphenopsids, pteridophytes and pteridosperms, noeggerathialeans, cycads, and cordaitaleans. This site may be the one that produces most substantial collection of the fossil bearing beds of the Taiyuan Formation. However, a remarkable feature of this flora is that there are very few genera and species in common with those of the Taiyuan Fm. previously known. A systematic investigation indicates that such assemblage differences are very likely due to changes of taphonomic and environmental phases, rather than evolutionary floral succession. In order to get a full and more precise understanding of the floral composition, succession and the floristic discrepancy in different depositional environments, an ecostratigraphic investigation on the Late Palaeozoic of Cathaysia should be advocated. In addition, the above mentioned dating of the tuff bed is nearly exactly on the Carboniferous and Permian boundary, so that the floral evolutionary changes may be investigated in the geological sections across the C-P boundary herein, which is a long-lasting issue in non-marine stratigraphy, and the results would prove this IUGS Geoheritage Site be globally extraordinary in stratigraphy.