Document Type
Article
Version Deposited
Published Version
Publication Date
7-20-2021
Publication Title
Geology
DOI
10.1130/G49011.1
Abstract
Delicate impressions in lacustrine strata of the lower Permian (lower Cisuralian) Usclas Formation record ephemeral freezing in equatorial Pangea. These sediments accumulated in the paleoequatorial and intramontane Lodève Basin (southern Massif Central, France) during peak icehouse conditions of the Late Paleozoic Ice Age. Experimental replication of these features supports the interpretation that they are ice-crystal molds. Evidence for films of ice in marginal-lacustrine sediment at such low latitudes and inferred low to moderate altitudes (1–2 km) calls for a reevaluation of climate conditions in eastern equatorial Pangea. Ephemeral freezing implies either cold tropical temperatures (~5 °C cooler than the Last Glacial Maximum) and/or lapse rates that exceeded those of the Last Glacial Maximum. Extreme continentality of the Lodève Basin would have amplified seasonality, albeit the climatic forcing(s) necessary to have promoted cold temperatures in equatorial Pangea remain enigmatic.
Recommended Citation
Lily S. Pfeifer; Brooke A. Birkett; Jean Van Den Driessche; Stéphane Pochat; Gerilyn S. Soreghan. Ice-crystal traces imply ephemeral freezing in early Permian equatorial Pangea. Geology (2021) 49 (11): 1397–1401.
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Comments
© 2021 The Authors Gold Open Access: This paper is published under the terms of the CC-BY license.