RECOGNITION OF THE KELLWASSER AND HANGENBERG ANOXIA EVENTS IN THE CENTRAL ASIAN OROGENIC BELT
The Devonian of northwest Xinjiang is part of the Central Asian Orogenic Belt (CAOB), bordered on the north by the Siberian Craton and on the south by the North China-Tarim Craton. The CAOB has a complex tectonic history and is thought to have formed as part of a complex amalgamation of intra-oceanic island arcs and continental fragments prior to the end of the latest Carboniferous. These results allow us to confirm the presence of the Kellwasser and Hangenberg Events in the open oceanic part of Paleotethys in contrast to the sections previously studied, which were located near Laurussia, Gondwana, Siberia, and South China. This indicates that the Kellwasser and Hangenberg Events were global in scope. The presence of an abundant diverse Famennian fauna between these anoxia (and extinction) events suggest that the shallow marine ecosystems in the CAOB were somewhat protected due to their tectonic location and relative isolation within an open ocean system. Due to the lack of studies from locations outside subequatorial North America and Europe the global extent of the extinction event is not well-constrained and studies such as this one aid in understanding the nature of ocean anoxia during this time period.