DEVONIAN FRASNIAN/FAMENNIAN TRANSITIONAL EVENT DEPOSITS AND SEA-LEVEL CHANGES
GONG Yiming
Li Baohua
Abstract：Seven kinds of physical event deposits have been recognized in the Frasnian/Famennian transition of both the passive continental margin of the South China plate and southern active continental margin of the Siberian plate. They are fine calcareous turbidite facies, calcareous breccia facies, limestone facies with soft-sediment deformation, wackestone facies with microspherules, tuffaceous breccia facies, black shale facies and volcanic explosive and effusive facies and they are widely distributed in the bottom of the Lower Palmatolepis triangularis zone of the Famennian and/or in the bottom of the Upper Palmatolepis rhenana zone of the Frasnian. These event deposits must have been induced by two-time asteroid impact events and should be good indicators of high resolution chronostratigraphic correlation. Data indicated that the sea-level changes were not synchronal and that there existed two types of saltatory and gradual sea-level changes, and five kinds of different characteristics in sea-level changes from the latest Frasnian to the earliest Famennian in China and other regions of the world. They were the latest Frasnian sea-level falling → the earliest Famennian sea-level rising, the latest Frasnian sea-level rising → the earliest Famennian sea-level falling, the latest Frasnian sea-level rising → the earliest Famennian sea-level rising, the latest Frasnian sea-level falling → the earliest Famennian sea-level falling, the Frasnian/Famennian transitional sea-level still. The stepped mass extinction of the Frasnian/Famennian transition may be closely related to six-time asteroid impact events from the bottom of the Upper Palmatolepis rhenana zone to the Palmatolepis crepida zone.
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Publication Date：2001-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 251-257 )