Palynological assemblages from the Majaditas Formation (Carboniferous), Argentina: An example of reworking in glacial sediments

Abstract

Reworked palynomorphs are commonly found in sedimentary deposits of glacial environments. However, instancesof reworking were few times identified in the Carboniferous assemblages of central-western Argentina. Inthis study, two well-preserved palynological assemblages recovered from shales bearing dropstones of theMajaditas Formation in San Juan province are described for the first time. The palynoflora comprises spores,monosaccate pollen, acritarchs, and prasinophyte. Although in a low proportion (at least 2%), some palynomorphscorrespond to reworked specimens of the underlying Devonian and Mississippian successions. Theassemblages are indicative of the Subzone A of the Raistrickia densa/Convolutispora muriornata Biozone thatcharacterizes the late Serpukhovian-early Bashkirian in the country. Close similarities are evident with otherpalynofloras described for glaciogenic deposits of the same age in the region.