Palynology of late palaeozoic sediments (Tupe Formation) at La Herradura Creek, San Juan province, Argentina

Abstract

Palynomorph assemblages recovered from the Tupe Formation at La Herradura Creek, San Juan province, Argentina, are analysed. The middle section of the sequence includes a marine fossiliferous interval belonging to the Tivertonia jachalensis-Streptorhynchus inaequiornatus (T-S) Faunal Biozone, recently ascribed an Early Permian age. The section below the marine fossiliferous unit yielded palynofloras typical of previously described 'Tupense' assemblages. The palynoflora recovered from beds above the marine horizon is diverse, relatively well preserved and includes species never recorded from the Tupe Formation. This latter palynoassemblage includes species diagnostic of Early Permian palynofloras such as Converrucosisporites confluens (Archangelsky & Gamerro) Playford & Dino, Pseudoreticulatispora pseudoreticulata (Balme & Hennelly) Bharadwaj & Srivastava, Horriditriletes ramosus (Balme & Hennelly) Bharadwaj & Salujha, Anapiculatisporites tereteangulatus (Balme & Hennelly) Playford & Dino, Laevigatosporites colliensis (Balme & Hennelly) Venkatachala & Kar, Marsupipollenites triradiatus Balme & Hennelly, Protohaploxypinus sewardii (Virkki) Hart and Pakhapites fusus (Bose & Kar) Menendez. Correlations with assemblages from western Argentina and other Gondwanan regions suggest an Early Permian age (not older than Asselian-Sakmarian) for the upper part of the sequence, supporting the age attributed to the T-S Biozone.