Cascada Grande Upstream waterfall "Green 1" (Pliocene of Argentina)

Also known as Cifuentes or de Aldaya, 2.85 km downstream from RN3

Where: Buenos Aires, Argentina (38.6° S, 60.6° W: paleocoordinates 38.7° S, 59.5° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Irene Formation, Early/Lower Pliocene (5.3 - 3.6 Ma)

• Prevosti et al. 2021: On analysis, one aliquot of a sample from QSLo (lower Quequén Salado, Paso del Halcón) presented extensive evidence of excess argon in the first half of the spectrum, but the final steps representing about 50% of released 39Ar yielded an age of 5.17 ± 0.08 Ma. A single aliquot of a sample from QSUp (upper Quequén Salado, Cascada Grande) gave an age of 4.33 ± 0.06 Ma. Our results close almost a century of argument concerning the relative antiquity of the “Irenean”( Kraglievich 1934, Goin et al. 1994, Pardiñas et al. 2017, Beilinson et al. 2017). The controversial lower fauna from the Quequén Salado River can now be shown to be of Zanclean age (5.17 Ma) and thus well within the Early Pliocene. Its upper fauna is also Early Pliocene (4.33 Ma), a point previously unclear.

Environment/lithology: terrestrial; massive, calcareous siltstone

• Sediments exposed upstream are greenish-white and largely carbonatic (Fig. 3). The basal layer (“green 1”) is a carbonatic massive silt; its upper portion contains lenses of sabulitic gravels cemented by carbonate that are laterally discontinuous. The overlying level (“green 2”) fills depressions cut into “green 1” when the contact between both layers is not mediated by the described conglomerate. The lateral contact between downstream and upstream sedimentary sections is clouded by the waterfall and its effects on oxidation affected the whole column about 15 m downstream the cascade. However, it seems clear that “green 1” overlies level #4.

Size class: macrofossils

Reposited in the MLP

Primary reference: U. F. J. Pardinas, F. J. Prevosti, D. Voglino and M. Cenizo. 2017. A controversial unit within the argentine neogene: the “Irenean” fauna. Ameghiniana 54(6):655-680 [E. Vlachos/E. Vlachos]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 191764: authorized by Evangelos Vlachos, entered by Evangelos Vlachos on 14.02.2018, edited by Kateryn Pino

Creative Commons license: CC BY (attribution)

Taxonomic list

Mammalia
 Rodentia - Caviidae
Caviidae indet. Gray 1821 caviomorph
 Rodentia - Ctenomyidae
Actenomys sp. Burmeister 1888 caviomorph
 Cingulata - Glyptodontidae
Glyptodontidae indet. Burmeister 1879 glyptodon
 Cingulata - Pampatheriidae
Pampatheriidae indet. Paula Couto 1954 edentate
 Cingulata - Dasypodidae
Doellotatus chapadmalensis Bordas 1932 armadillo
 Notoungulata - Hegetotheriidae
Paedotherium sp. Burmeister 1888 notoungulate
Reptilia
 Squamata -
Tupinambis sp. Daudin 1802 tegu