Cyclostratigraphic calibration of the rhythmically bedded upper Famennian (Upper Devonian) in the Rhenish Massif, Germany
Wichern, Nina; Becker, R. Thomas; Bialik, Or M.; Hartenfels, Sven; Vleeschouwer, David De
Newsletters on Stratigraphy Volume 59 Number 3 (2026), p. 269 - 291
82 references
published: Aug 17, 2026
published online: Jan 30, 2026
manuscript accepted: Jan 9, 2026
manuscript revision requested: Dec 2, 2025
manuscript received: Aug 18, 2025
DOI: 10.1127/nos/0908
Open Access (paper may be downloaded free of charge)
Abstract
In recent years, cyclostratigraphy has significantly improved the accuracy and precision of the Devonian timescale, especially at stage boundaries. Yet, the body of Devonian stages often remains undefined in terms of cyclostratigraphy. Here, we present a new astrochronological framework for the upper to uppermost Famennian based on XRF-derived elemental proxy records from two rhythmic marine successions in the Rhenish Massif (Germany). The composite record spans the interval from the Annulata Events to the Hangenberg Crisis (the end-Devonian extinction pulse) and reveals a 5.7 ± 0.4 Myr duration. We resolve a 2.3 Myr interval between the Annulata and Dasberg black shales, and 2.4 Myr between the Dasberg and Hangenberg black shales. There is an estimated 67 kyr between the Lower and Upper Annulata black shales. Additionally, we constrain the durations of nine conodont biozones. Our results are consistent with several previous studies and strengthen the case for integrating multiple astrochronologies and to construct correlatable astrochronozones between globally distributed sections. The emerging 2.3–2.4 Myr rhythm of the Annulata–Dasberg–Hangenberg sequence supports the hypothesis that Late Devonian anoxic events were modulated by long-eccentricity forcing, underscoring a strong astronomical pacing of Late Devonian palaeoenvironmental change.
Keywords
Devonian • Famennian • cyclostratigraphy • XRF • Rhenish Massif • Hangenberg