Devonian Frasnian-Famennian transitional event deposits of Guangxi, South China and their possible tsunami origin

Abstract

A suite of event deposits, isochronous and interrelated in origin, occurs widely near the FrasnianFamennian boundary in Guangxi, South China. It is mainly distributed in the facies areas of the platform-margin slope and inter-platform rift-trough. The rudstone or calcirudite occur in the Liujing section of Hengxian and Luoxiu and Baqi sections of Xiangzhou in the facies area of platform-margin slope. The turbidites are observed in the sections of Yangdi and Baisha of Guilin, Du'an of Debao, Nandong and Sanli of Wuxuan, Xiangtian, Ma'anshan of Xiangzhou, Nayi of Chongzuo, Yunpan of Shanglin in the facies area of inter-platform rift-trough. The massive homogenites occur in sections of Mangchang, Luofu and Road from Nandan to Tian'e and Ma'anshan etc in the facies area of inter-platform rift-trough. Herein event deposits can be correlated in stratohorizon to the turbidite in the bottom of the Lower triangularis Zone in Hony railroad cut of Belgium, Devils Gate of Nevada, USA, Atrous of Morocco, South Urals and Fore-Kolyma of northeastern Siberia of Russia, and erosional discontinuities and brecciation in the Frasnian-Famennian boundary in South Polish-Moravian shelf. The event deposits could be caused by a violent tsunami related to bolide impacts into ocean.

Kellwasser horizons, sea-level changes and brachiopod–coral crises during the late Frasnian in the Namur–Dinant Basin (southern Belgium): a synopsis

“…Similar storm/tsunami deposits have been also reported elsewhere in the same stratigraphic interval (Racki et al 2002;Bond & Wignall 2008;Du et al 2008;Carmichael et al 2014). The UKW is responsible for the last Frasnian extinctions of brachiopods (e.g.…”

Pulses of enhanced continental weathering associated with multiple Late Devonian climate perturbations: Evidence from osmium-isotope compositions

“…The ultimate causes of the various Late Devonian environmental perturbations remain debated. Numerous triggers have been postulated for the Kellwasser crises, including extra-terrestrial impacts (e.g., Wang, 1992;Claeys et al 1996;Du et al, 2008), large-scale volcanic activity potentially linked to the Viluy Traps in Siberia (e.g., Courtillot et al, 2010;Ricci et al, 2013;Racki et al, 2018), orogenic uplift and erosion (Averbuch et al, 2005), and the expansion of vascular-rooted terrestrial flora (Algeo et al, 1995;Algeo and Scheckler, 1998). Many of the environmental perturbations also appear to have coincided with climate cooling (e.g., Streel et al, 2000;Joachimski and Buggisch, 2002;Balter et al, 2008).…”

A new model for the Kellwasser Anoxia Events (Late Devonian): Shallow water anoxia in an open oceanic setting in the Central Asian Orogenic Belt

“…The Frasnian-Famennian extinction is stratigraphically associated with the Upper and Lower Kellwasser Anoxia Events, a pair of ocean anoxia events characterized by bituminous limestone or black shale sequences. The Kellwasser Events are associated with sustained or intermittent anoxia, enhanced productivity, and storm or tsunami deposits (Sandberg et al, 1988, Racki et al, 2002, Du et al, 2008and Bond et al, 2013. Sea level oscillations, tectonic forcing, and ocean stratification have frequently been considered the primary drivers of the Kellwasser Events (Sandberg et al, 1988, Joachimski and Buggisch, 1993, McGhee, 1996, Chen et al, 2002, Bond et al, 2004, Tribovillard et al, 2004and Chen et al, 2013, although when taken together these proposed mechanisms for anoxia development are somewhat contradictory and are dependent on local topography or tectonic forcing (Racki, 2005).…”