Extinction
events mark crises in the history of life, and recovery from these events
commonly is protracted. To better
understand the timing, nature, and controls of post-Permian biotic recovery, Galán-Abellán et al. document petrography,
whole-rock geochemistry, and isotopic analyses of early diagenetic aluminium-phosphate-sulphate
(APS) minerals in Early-Middle Triassic continental sandstones in the Iberian Ranges
(Iberian Peninsula). Sr and S isotopes
indicate mixed sources for these elements, derived from the dissolution of
pre-existing detrital minerals (phosphates, K-feldspar, clay minerals and
pyrite) and from marine and volcanic aerosols. The formation of APS minerals is
interpreted to be related to acid meteoric waters, which in turn reflect arid,
acidic conditions unfavorable to biotic recovery after the Permian–Triassic
biotic crisis. The study suggests that
analysis of APS minerals and Sr and S isotopes, coupled with sedimentologic and
stratigraphic analysis, can provide enhanced means to assess on
paleoenvironmental change and biotic recovery.
Sources of Sr and S inaluminum-phosphate–sulfate minerals in Early–Middle Triassic sandstones(Iberian Ranges, Spain) and paleoenvironmental implications for the west Tethys
by
Belén Galán-Abellán, Jacinto Alonso-Azcárate, Robert J. Newton, Simon H.
Bottrell, José F. Barrenechea, M. Isabel Benito, Raúl De la Horra, José
López-Gómez, and Javier Luque
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