Carbon isotopic evidence for organic matter oxidation in soils of the Old Red Sandstone (Silurian to Devonian, South Wales, UK)

A T Brasier, J L Morris, R D Hilier

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)
13 Downloads (Pure)

Abstract

Petrographic and calcrete carbon isotope data from seasonally waterlogged Upper Silurian (Pridoli) to Lower Devonian (Pragian) palaeo-Vertisols of the Old Red Sandstone, South Wales, UK, are presented. The delta C-13 values mostly range from -9 to -12% (VPDB), suggesting that the soils were inhabited by abundant vegetation that when oxidized (perhaps with microbial assistance) resulted in CO2-rich soils. Such soils would favour calcrete precipitation through equilibration of soil zone CO2 with the relatively lower atmospheric pCO(2). However, reliably estimating palaeoatmospheric pCO(2) using these carbon isotope data is a challenge.

Original languageEnglish
Pages (from-to)621-634
Number of pages14
JournalJournal of the Geological Society
Volume171
Issue number5
Early online date7 Jul 2014
DOIs
Publication statusPublished - Sept 2014

Bibliographical note

This work was part-supported by a grant from the E. J. Garwood Fund (2011) of the Geological Society of London. J. Dougans (SUERC) and S. Verdegaal (VU Amsterdam) kindly assisted with some of the stable isotope measurements. D. Brasier kindly assisted with fieldwork. Work on Tredomen Quarry calcrete samples was conducted by J.L.M. as part of a PhD thesis funded by the School of Earth and Ocean Sciences, Cardiff University, under the supervision of V. P. Wright and D. Edwards. Core drilling was partly funded by the British Geological Survey. Thanks go to J. Becker (Cardiff University) for isotopic analysis of the Tredomen Quarry calcretes, and to G. Abbott (Newcastle University) and Iso-Analytical Ltd for isotopic analysis of fossil plant material. Three anonymous reviewers and the editor made helpful suggestions that improved the quality of the paper.

Keywords

  • Anglo-Welsh basin
  • ridgeway conglomerate formation
  • atmospheric CO2
  • pedogenic carbonate
  • SW Wales
  • Paleozoic atmosphere
  • Bloomsburg formation
  • phanerozoic time
  • vertic paleosols
  • Townsend-Tuff

Fingerprint

Dive into the research topics of 'Carbon isotopic evidence for organic matter oxidation in soils of the Old Red Sandstone (Silurian to Devonian, South Wales, UK)'. Together they form a unique fingerprint.

Cite this