Also known as Zone of Chasichimys bonaerense
Where: La Pampa, Argentina (37.4° S, 65.5° W: paleocoordinates 37.6° S, 62.6° W)
• coordinate stated in text
• outcrop-level geographic resolution
When: Chasicoan mammal zone, Cerro Azul Formation, Chasicoan (10.0 - 9.0 Ma)
• Early late Miocene
•The stratotype is the lower level of the Cerro Azul Formation outcropping at this locality
•Montalvo et al. 2019: The revision of the vertebrate assemblage from this locality, as well as new geomorphologic and sedimentological interpretations of the Cerro Azul Formation in the area, confirms the previous assignation to the Chasicoan age.
Environment/lithology: fluvial; lithified, massive, red, sandy siltstone and lithified, medium-grained, sandy conglomerate
•The amalgamated conglomeradic–sandy bodies suggest the episodic development of perennial streams without flow division on a loessic substrate.
•Schmidt et al. 2018: Levels of Cerro Azul formation at Cerro La Bota represent an ephemeral fluvial event (Goin et al. 2000; Verzi et al. 2008).
•Montalvo et al. 2019: The FA1 crops out in the lower part of the studied section and is 1.7 m thick (Fig. 2). It includes sheet-like strata with non-erosive bases, composed of massive and commonly very fine-grained siltstones (facies Fsm) with root traces (facies P).The FA2 is 2.2 m thick and overlays FA1 deposits with erosive contact (Fig. 2). It is constituted by a lateral and vertical erosive superposition of sandstone (facies St) and conglomeratic (facies Gt) bodies.
Size classes: macrofossils, mesofossils
Collection methods: Montalvo et al. 2019: specimens recovered belong to the Paleontological Collection of the Facultad de Ciencias Exactas y Naturales, Universidad Nacional de La Pampa (La Pampa Province, Argentina).
•Esteban, et al. 2000: Todos los ejemplares analizados están depositados en
•la Cátedra de Geología Histórica de la Facultad de Ciencias Exactas y Naturales de la Universidad Nacional ele La Pampa, Argentina, cuyo acrónimo es GHUNLPam
Primary reference: D. H. Verzi, C. I. Montalvo, and C. M. Deschamps. 2008. Biostratigraphy and biochronology of the Late Miocene of central Argentina: Evidence from rodents and taphonomy. Geobios 41:145-155 [C. Jaramillo/M. Vallejo] more details
Purpose of describing collection: biostratigraphic analysis
PaleoDB collection 152063: authorized by Carlos Jaramillo, entered by Maria Vallejo on 05.11.2013, edited by Grace Varnham and Miranta Kouvari
Creative Commons license: CC BY (attribution)