The Silurian-Devonian Boundary of China: Review and perspectives

The Silurian-Devonian Boundary (SDB) was the first Global Stratotype Section and Point (GSSP) to be established. Extensive and well-preserved SDB strata are found in Western Europe and North America. Territory of China is composed of multiple plates and terranes, which were located in the equatorial and low-latitude regions of the northern hemisphere during the late Silurian to the Early Devonian. Due to the Kwangsian Orogeny, continuous Silurian-Devonian sequences are absent in the main parts of North China, Yangtze, and Tarim cratons in China. Accordingly, continuous stratal sections across the SDB have only been sporadically reported from the orogenic belts and southwestern margin of South China. The lack of continuous carbonate sediments during the Silurian-Devonian and scarcity of fossil markers obtained has long time limited for complex research on the SDB in China. However, the discovery of the conodont Caudicriodus woschmidti in several regions, and the widespread presence of encrinurid trilobites and crinoids, have allowed recognition of the SDB in China. Abundant volcanic material near the SDB facilitates high-precision chronological studies. Apart from the global delta 13C positive excursion and Icriodus Event above the SDB, most other events are only evident in certain regions or even in a single section. Therefore, there is an urgent need for more data and evidence from other areas and plates. This work summarizes research on the SDB in China from various tectonic settings, tectonic plates, and from different facies and regions, and provides a brief review of the research history, current state of art, achievements in study of the SDB in China, and outlines prospects for future research.