J 2022

The Devonian-Carboniferous transition at Borkewehr near Wocklum (northern Rhenish Massif, Germany) – a potential GSSP section

HARTENFELS, Sven, Ralph Thomas BECKER, Hans-Georg HERBIG, Wenkun QIE, Tomáš KUMPAN et. al.

Basic information

Original name

The Devonian-Carboniferous transition at Borkewehr near Wocklum (northern Rhenish Massif, Germany) – a potential GSSP section

Authors

HARTENFELS, Sven (guarantor), Ralph Thomas BECKER, Hans-Georg HERBIG, Wenkun QIE, Tomáš KUMPAN (203 Czech Republic, belonging to the institution), De Vleeschouwer DAVID, Dieter WEYER and Jiří KALVODA (203 Czech Republic, belonging to the institution)

Edition

Palaeobiodiversity and Palaeoenvironments, Heidelberg, Springer, 2022, 1867-1594

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10505 Geology

Country of publisher

Germany

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 1.400

RIV identification code

RIV/00216224:14310/22:00129167

Organization unit

Faculty of Science

UT WoS

000833488000001

Keywords in English

Devonian; Carboniferous Boundary; Hangenberg Crisis; Conodonts; Stratigraphy; Geochemistry; Rhenish Massif

Tags

Tags

International impact, Reviewed
Změněno: 5/1/2023 11:49, Mgr. Marie Šípková, DiS.

Abstract

V originále

The Borkewehr section near Balve at the southeastern end of the Remscheid-Altena Anticline is currently the best and most complete Devonian/Carboniferous Boundary (DCB) succession of the Rhenish Massif, Germany. Based on a multidisciplinary approach, focusing on refined conodont and ammonoid biostratigraphy, microfacies analyses, sequence stratigraphy, carbon isotopes (C-org and C-carb), trace element geochemistry, including REE data, and cyclostratigraphy, the section is proposed as a candidate for the new basal Carboniferous GSSP. The succession represents a pelagic "seamount" setting. It spans the upper Famennian to lower Visean, with a condensed development of most Rhenish lithostratigraphic units and sedimentary sequences. It is the type-section of the oxic and strongly cyclic, fossiliferous Wocklum Limestone and of important uppermost Famennian and basal Carboniferous index species. The First Appearance Datum (FAD) of Protognathodus kockeli s.str., in a phylogenetic succession from the ancestral Pr. semikockeli n. sp., is proposed as future GSSP level. This FAD is sandwiched between many other marker levels for global correlation. Below are, from base to top, the transgressive base of the at least partly anoxic Hangenberg Black Shale (base Lower Hangenberg Crisis Interval), the Hangenberg Regression (onset of siltstones of the basal Middle Crisis Interval), the level of maximum regression, indicated by maximum Zr/Al values, and the initial transgression of the basal Upper Crisis Interval, marked by the re-onset of carbonate deposition. Above follow the locally cryptogenic FAD of Siphonodella (Eosiphonodella) sulcata s.l. at the base of the post-Crisis Interval (Hangenberg Limestone), associated with a conodont biofacies shift, the FAD of Si. (Eo.) bransoni, and, much higher, the sharp Lower Alum Shale Event at the base of the classical middle Tournaisian. The significance of the section is greatly enlarged by its precise correlation with numerous other Rhenish DCB sections that provide important additional data on faunas, geochemistry, geochronological ages, and magnetic susceptibility. The new Borkewehr data suggest changes of weathering intensity, based on Rb/K and K/Al trends, and Milankovitch cyclicity associated with the climate changes of the Hangenberg Crisis. The local conodont extinction rate at the top of the Wocklum Limestone lies at 57 % while there are no survivors in ammonoids, trilobites, or deep-water corals. Positive carbon isotopic shifts of carbonate in the Upper Crisis Interval and of C-org in the Middle Crisis Interval are decoupled, which suggests complex underlying processes that are not yet understood.

Links

GA19-17435S, research and development project
Name: Paleoklimatologický význam paleozoických červených pelagických karbonátů: časově specifické facie nebo produkty mikrobiální aktivity?
Investor: Czech Science Foundation