Open AccessSPONGE SPICULE ASSEMBLAGES FROM THE MIDDLE ORDOVICIAN OF PONÓN TREHUÉ, SOUTHERN MENDOZA, ARGENTINA
Author(s) -
Matilde Sylvia Beresi,
Susana Heredia
Publication year - 2021
Publication title -
spanish journal of paleontology/spanish journal of palaeontology
Language(s) - English
Resource type - Journals
eISSN - 2660-9568
pISSN - 2255-0550
DOI - 10.7203/sjp.15.1.22011
Subject(s) - sponge spicule , spicule , ordovician , geology , paleontology , carbonate platform , sponge , carbonate , facies , biostratigraphy , materials science , structural basin , metallurgy
Sponge spicule assemblages are described fom residues of conodont samples from Ordovician strata in the Sierra Pintada, southern Mendoza Province, Argentina. Spicules have been recovered from the Arenigian allochthonous megaconglomerates and from autochthonous limestones and carbonates sandstones of the Ponón Trehue Formation. This formation is a elastic-carbonate sequence representing olistostromic and turbidite facies. Conodonts in this formation are Llandeillan in age. The spicules are calcified and moderately preserved. The material shows a low diversity. Poriferan taxa found in this formation include heteractinid spicules as well as hexactinellid hexactines and non-lithistid demospongiid triaene and oxeas with some doubt. Associations of exclusively heteractinid spicules are restricted to allochthonous blocks of the shallow carbonate platform of the San Juan Formation (Arenig). In the outer platform and slope, autochthonous calcarenites and dark limestones contain hexactine spicules. These spicules evidence the existence of sponges in the Ordovician of the Ponón Trehue area, as a part of the Precordillera terrane.