Fitxers
Tipus de document
ArticleVersió
Versió publicadaData de publicació
Tots els drets reservats
Si us plau utilitzeu sempre aquest identificador per citar o enllaçar aquest document: https://hdl.handle.net/2445/64687
Crassostrea patagonica (d'Orbigny, 1842) shell concentrations from the late Miocene Rio Negro province, NE Patagonia, Argentina
Títol de la revista
Director/Tutor
Contribució addicional
ISSN de la revista
Títol del volum
Resum
The Río Negro Formation (late Miocene-early Pliocene) mainly consists of continental deposits, but it contains a middle member of marine origin. It represents a transgressive-regressive sequence that can be seen at several outcrops along the N Patagonian coast. The taphonomical approach to the El Espigón marine deposits permits the identification of four main layers containing different kinds of skeletal accumulation, which mainly consist of oyster shells [Crassostrea patagonica (D'Orbigny, 1842)]. These concentrations display three different morphologies (pouches, pavements and bouquets) with a different taphonomic signature. These deposits were formed in shallow marine environments influenced by wave activity that produced valve concentrations of different entities. They contain several shell beds that represent event, composite, hiatal to lag skeletal concentrations. Traces of bioturbation in the sediment (Thalassinoides, Teichichnus) and bioerosion on the shells (Entobia, Gastrochaeonolites, Caulostrepsis), and encrusters (cirripeds, bryozoans), are also abundant in the outcrop and consititue common components of these Miocene materials. Layers 1 and 2 of the sequence were deposited in shoreface/foreshore environments at the beginning of a highstand systems tract, while layers 3 and 4 were deposited at the end, or at the beginning of a forced regression, in foreshore environments. A final erosional episode cut the top of the layer 4, which truncated the abundant bioturbaation developed there.
Recurs relacionat
Matèries
Matèries (anglès)
Citació
Citació
DOMÈNECH, Rosa, FARINATI, Ester A. and MARTINELL, Jordi. Crassostrea patagonica (d'Orbigny, 1842) shell concentrations from the late Miocene Rio Negro province, NE Patagonia, Argentina. Spanish Journal of Palaeontology. 2014. Vol. 29, num. 2, pags. 165-182. ISSN 2255-0550. [consulted: 2 of October of 2026]. Available at: https://hdl.handle.net/2445/64687