ammonites
banner
Gateway to the Paleobiology Database
Arroyo Chasicó (Miocene of Argentina)

Where: Buenos Aires, Argentina (38.6° S, 63.0° W: paleocoordinates 38.8° S, 60.1° W)

• coordinate estimated from map

• local area-level geographic resolution

When: Arroyo Chasicó Formation, Chasicoan (10.0 - 9.0 Ma)

• A recent interpretation of radiometric and paleomagnetic data of the ACF supports an age between at least 9.43 and 8.7 Ma (Zarate et al., 2007).

• formation-level stratigraphic resolution

Environment/lithology: "floodplain"; sandstone

• The beginning of Chasicoan sedimentation was placed after the general withdrawal of the mid-Miocene transgression (Pascual et al., 1996). According to Ramos (1999b), the transgression extended across most of eastern South America, covering the Pampas, Chaco region, and Patagonia up to the Andean foothill and reaching areas near the central and northern Andes of Argentina. The regional regression that followed was thought to be synchronous with the 10.5 Ma global sea level fall cited by Haq et al. (1987) (see Verzi, 1999, Pascual et al., 1996).
• an extensive plateau capped by a thick calcrete crust, which in turn is covered by a thin apron of late Pleistocene–Holocene eolian deposits.

Size class: macrofossils

Preservation: permineralized

Primary reference: M. A. Zárate, P. H. Schultz, A. Blasi, C. Heil, J. King and W. Hames. 2007. Geology and geochronology of type Chasicoan (late Miocene) mammal-bearing deposits of Buenos Aires (Argentina). Journal of South American Earth Sciences 23:81-90 [D. Croft/D. Croft] more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 79180: authorized by Darin Croft, entered by Darin Croft on 27.02.2008, edited by Bettina Kaphingst, Juan Carrillo, Jelle Zijlstra, Miranta Kouvari and Evangelos Vlachos

Creative Commons license: CC BY (attribution)