Biostratigraphy, sedimentology and sequence stratigraphy of the Tournaisian–Viséan transitional strata in South China (Guangxi)

Abstract

The biostratigraphy and sedimentological evolution of the Tournaisian±Vise an (T±V) transitional strata in South China (Guangxi) have been investigated. The sediments were deposited on a carbonate platform and in slope and basinal environments. In the T±V transitional strata, six foraminiferal associations have been distinguished which allow correlation between the shallow and deep water deposits. A careful examination of the evolutionary stages of the foraminifer Eoparastaella provides a more accurate criterion for the de®nition of the T±V boundary, but does not signi®cantly modify the historical one. The distinction of two morphotypes is based on the elevation of the last whorl and the peripheral outline. Tournaisian specimens of Eoparastaella have a well rounded periphery (morphotype 1) contrasting with the subangular periphery of younger Vise an specimens (morphotype 2). A coecient can be deduced from simple biometric measurements for more precisely de®ning the T±V boundary.The sequence stratigraphy of the T±V strata in South China has been reconstructed by combining biostratigraphical and sedimentological data. It allowed the correlation of the T±V transitional strata between the platform area and the slope and basinal locations. Late Tournaisian strata were deposited during a highstand systems tract. Near the end of the Tournaisian, a major drop in relative sea-level led to the development of an unconformity in the platform area. Lowstand deposits formed during latest Tournaisian time in the basin where a detailed biostratigraphic framework has been devised. Sediments deposited during the ensuing transgressive systems tract overlie the late Tournaisian highstand sediments in the platform area and the latest Tournaisian lowstand deposits in the basin. A major drop in relative sea-level near the end of the Tournaisian has been recognized worldwide. Therefore, the possibility of using the sequence stratigraphy of the T±V strata in South China for worldwide correlations should be investigated.

Lower Carboniferous carbon isotope stratigraphy in South China: Implications for the Late Paleozoic glaciation

“…A major drop (<150 m) in sea level near the Tournaisian-Visean boundary has been recognized in South China and Europe, and led to abrupt changes of facies, unconformities, and palaeokarstic surface, which is consistent with the second major δ 13 C positive shift in South China [44,45].…”

Petrophysical and geochemical signature of the Hangenberg Events: an integrated stratigraphy of the Devonian-Carboniferous boundary interval in the Northern Rhenish Massif (Avalonia, Germany)

“…Incised valleys infilled by siliciclastics were documented in Morocco ) and the siliciclastic intervals overlying the Hangenberg Black Shale Event horizon in the Central Hunan (Hance et al 1994), in Ohio and Kentucky (Coleman & Clayton 1987) or Moravian Karst (Kumpan et al 2014a), as well as in the studied sections from the Rhenish Massif (Bless et al 1993, see Kaiser et al 2011 andreferences therein). Inevitably for such a sea-level drop, gaps of variable stratigraphic extent are known from DCB in many places, e.g., Belgium (Hance et al 1994, Kumpan et al 2014b, Spain (García-Alcalde & Menédez-Alvarez 1988), Colorado (Myrow et al 2013) or Kentucky (Coleman & Clayton 1987). The rapid increase in Zr/Al ratio in the Hangenberg Sandstone at Drewer and Oese is consistent with the interpretation of Zr/Al as a proxy for coarse-grained siliciclastics.…”

“…The reduced levels of atmospheric CO 2 in combination with the Gondwana passage through the southern polar region (Caplan & Bustin 1999;Isaacson et al 2008) caused global cooling and the growth of glaciers (Caputo et al 2008). The rapid global cooling led to the third phase of the HE (the Hangenberg Shale and Sandstone Event; HSE), which is represented by deposition of increasingly medium to coarse-grained siliciclastic sediments in the marine environment and/or gaps in sedimentary records all over the world (Van Steenwinkel 1993, Hance et al 1994, Becker 1996: holostratigraphic levels 10-11; , Myrow et al 2013, Kumpan et al 2014b.…”

Mississippian (Early Carboniferous) sequence stratigraphy of the Rhenish Kulm Basin, Germany

“…For the latest Devonian ('Strunian') and the DevonianCarboniferous transition, already Hance et al (1993) recognized an identical sequence stratigraphic development in southern China and Belgium. This study followed on a first approach to that time slice in Belgium by Van Steenwinkel (1990.…”