TRAZAS FOSILES DE LA FORMACION EL CHACAY (EOCENO), EN LA MESETA BELGRANO, SANTA CRUZ, ARGENTINA

Authors

  • Jorge O. Chiesa CONICET. Departamento de Geología y Minería, Universidad Nacional de San Luis, San Luis.

Abstract

The Paleogene marine sedimentary succession of northwestern Santa Cruz province is analyzed. A transgressive-regressive cycle with three sections deposited in a shallow marine siliciclastic shelf paleoenvironment is suggested. These successions contain important horizons with invertebrate fossils. Systematic ichnology, ethology, and paleoenvironmental aspects are considered. The trace fossil assemblage is grouped in two ichnocoenoses: Ichnocoenosis A: dwelling structures of suspension feeders in a sandy substrate of a shallow water platform (Mocaronichnus and Arenicolites); lchnocoenosis B: dwelling/feeding structures of deposit feeders in a muddy substrate of a distal platform (Rhizocorallium and Thalassinoides). The monoespecific association of Thalassinoides belongs to the Glossifungites ichnofacies. This association develops on a firmground related to an omission surface.

KEY WORDS. Argentina. Santa Cruz. Eocene. El Chacay Formation. lchnology. Systematics. Paleoenvironment.

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Published

2015-10-01

Issue

Vol. 4 No. 1 (1996)

Section

Thematic Volume

License

Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a CC Attribution-NonCommercial 4.0 that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.