Permian loess and dust in the Lodève basin (France)Lily - INSU - Institut national des sciences de l'Univers Access content directly
Conference Papers Year : 2021

Permian loess and dust in the Lodève basin (France)Lily

Abstract

French Carboniferous–Permian sedimentary basins record intramontane paleoequatorial climateduring Pangean assembly, ice-age collapse, and megamonsoon inception. Herein we present datato elucidate the provenance, depositional character, and climatic signals recorded in the ~1.5 kmthickPermian Salagou Formation (Lodève Basin, southern Massif Central, France). The SalagouFormation predominantly consists of fine-grained red beds – Transitioning up-section frominternally massive red mudstone (with local pedogenic fea-tures) to mudstone commonlyinterbedded with sedimentary structures that record intermittent shallow water. We interpretthese strata to reflect eolian transport and ultimate deposition as loess, or in shallow, ephemerallacustrine environments. Provenance analyses record rapid (1-17mm/year) exhumation of localVariscan basement during early Permian syn-orogenic extension. The coarse-grained nature ofprotoliths and geochemistry data that suggests minimal chemical weathering suggests that thegeneration of silt occurred by physical (cold-weathering processes). This work adds to a record ofvoluminous loess across low-latitude Pangea that archives a dusty atmosphere, potentially linkedto glaciated alpine terranes. Finally, analysis and modeling of rock magnetic data recordsMilankovitch-scale paleoclimatic variability (predominant orbital eccentricity-scale, ~10-m- thick)through the middle to late Cisuralian (ca. 285—275 Ma) and optimal sedimentation rates between9.4 - 13 cm/kyr.
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Dates and versions

insu-03521101 , version 1 (11-01-2022)

Identifiers

  • HAL Id : insu-03521101 , version 1

Cite

Lily Pfeifer, Gerilyn S Soreghan, Pochat Stéphane, Jean van den Driessche. Permian loess and dust in the Lodève basin (France)Lily. 27ème Réunion des sciences de la Terre, Nov 2021, Lyon, France. pp.228. ⟨insu-03521101⟩
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