Ordovician Trace Fossils of Argentina

Ordovician trace fossils of Argentina. Trace fossils are recurrent elements in the Ordovician strata of Argentina. Biogenic structures commonly occur in siliciclastic and limestone sequences (with or without volcanigenic participation), characterizing different aspects related to the behaviour of the producer organism under a spectrum of different paleoenvironmental conditions. Shelf, talus, estuarine and deltaic facies with particular conditions were colonized during the Ordovician, being reflected by the record of the ichnological forms within sequences. The scarcity of typical deep water traces support the existence of relatively large shallow platform over much of Argentina during the period, with the exception of the western Puna deeper facies. The Ordovician biodiversification is recorded by the increasing ichnodiversity within the strata that includes the Cambro-Ordovician transition. Tremadocian strata display mid to high diversity ichnoassemblages, while Arenig sandstones in NW Argentina outstands by low to mid diversity impressive ichnofossiliferous pavements. Younger sediments display a general deepenning of facies with an increasing ichnodiversity. A tight relation between ichnological associations and paleoenvironmental conditions is highligted by means of sedimentological characters and environmental interpretation of sequences.