Devonian events: examples from the eastern Palaeotethys (Si Phai section, NE Vietnam)

Abstract

Recent study of Middle to Upper Devonian deposits in the Dong Van area, northeast Vietnam, has revealed new, more detailed information of both the stratigraphic record of the Si Phai section and global Devonian bioevents. Four possible equivalents of well-known Devonian events of different magnitude were found in Vietnam, an area which is underrepresented in that respect: the (?) Kacak Event, the (?)pumilio Events, the late Middle Givetian Taghanic Event and the Frasnian/Famennian Kellwasser Event. The stratigraphic framework of the Si Phai section allows us to recognise and assess the timing of global Devonian bioevents in Vietnam even though the section is not continuous. An overview of the sedimentological development of the Si Phai section is discussed briefly where carbonates in the section are composed of argillaceous limestones suggesting relatively deep, off-shore conditions. Due to the facies setting, the macrofauna is generally rare and the conodont record is likewise limited in some parts. Nevertheless, it is possible to pinpoint some global event intervals for the first time in Vietnam.