The isotopic composition of pedogenic carbonate as a record of pCO2: Insights from the Late Paleozoic of tropical western Pangea

Tanner, Lawrence H.; Lucas, Spencer G.

Abstract

The use of the carbon isotope composition (δ13C) of pedogenic calcite as a proxy for pCO2 was established over three decades ago and remains a primary means of investigating climate history. Over time, an increased understanding of the systematics of pedogenic carbonate precipitation has improved the constraints on interpreting paleoatmospheric composition from the isotopic composition of calcrete. We review the development of the use of pedogenic δ13C as a proxy for pCO2 over geologic time, with focus on the late Paleozoic. We illustrate the discussion with specific examples from the late Carboniferous through early Permian icehouse climate interval and present new as well as previously published data from strata of Virgilian (Late Pennsylvanian) through Wolfcampian (early Permian) age collected in northern and south-central New Mexico, which was located in tropical western Pangea during the late Paleozoic. Our success in fitting pCO2 values we generate through new analyses to previously published paleo-pCO2 curves strengthens the rationale for use of these data as proxies for paleoclimate and suggests the potential for their use as a correlation tool.

Citation

Tanner, L. H., & Lucas, S. G. (2020). The isotopic composition of pedogenic carbonate as a record of pCO2: Insights from the Late Paleozoic of tropical western Pangea. In M. Montenari (Ed.), Stratigraphy & Timescales (529-565). Elsevier. https://doi.org/10.1016/bs.sats.2020.08.009

• Online Publication Date: Sep 13, 2020
• Publication Date: 2020
• Deposit Date: Jun 6, 2023
• Publisher: Elsevier
• Pages: 529-565
• Series Title: Carbon Isotope Stratigraphy
• Series ISSN: 2468-5178
• Book Title: Stratigraphy & Timescales
• Chapter Number: 10
• ISBN: 978-0-12-820991-2
• DOI: https://doi.org/10.1016/bs.sats.2020.08.009