Document Type

Article

Version Deposited

Published Version

Publication Date

1-9-2023

Publication Title

Geological Society, London, Special Publications

DOI

10.1144/SP535-2022-208

Abstract

Palaeo-loess and silty aeolian-marine strata are well recognized across the Carboniferous–Permian of equatorial Pangaea. Aeolian-transported dust and loess appear in the Late Devonian in the west, are common by the Late Carboniferous, and predominate across equatorial Pangaea by the Permian. The thickest loess deposits in Earth history – in excess of 1000 m – date from this time, and archive unusually dusty equatorial conditions, especially compared to the dearth of equatorial dust in the Cenozoic. Loess archives a confluence of silt generation, aeolian emission and transport, and ultimate accumulation in dust traps that included ephemerally wet surfaces and epeiric seas. Orogenic belts sourced the silt, and mountain glaciation may have exacerbated voluminous silt production, but remains controversial. In western Pangaea, large rivers transported silt westward, and floodplain deflation supplied silt for loess and dust. Expansion of dust deposition in Late Pennsylvanian time records aridification that progressed across Pangaea, from west to east. Contemporaneous volcanism may have created acidic atmospheric conditions to enhance nutrient reactivity of dusts, affecting Earth's carbon cycle. The late Paleozoic was Earth's largest and most long-lived dust bowl, and this dust represents both an archive and agent of climate and climate change.

Comments

© 2023 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution License

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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