Revised stratigraphy of Neogene strata in the Cocinetas Basin, La Guajira, Colombia

Abstract

The Cocinetas Basin of Colombia provides a valuable window into the geological and paleontological history of northern South America during the Neogene. Two major findings provide new insights into the Neogene history of this Cocinetas Basin: (1) a formal re-description of the Jimol and Castilletes formations, including a revised contact; and (2) chronostratigraphy presented here provides the necessary background information to explore the complete evolutionary and biogeographic significance of the excellent fossil record of the Cocinetas Basin.

A 60-million-year Cenozoic history of western Amazonian ecosystems in Contamana, eastern Peru

“…The Neogene period is mostly documented in two distinct areas, near the Colombian-Venezuelan border (La Guajira Peninsula; Fig. 1A; fluviolacustrine to marine environments; lower-middle Miocene UitmaJimol-Castilletes formations; e.g., Moreno et al, 2015) and in the Huila Department (La Venta area; fluviolacustrine environments; middle Miocene Villavieja and La Victoria formations; e.g., Stirton, 1953;Kay and Madden, 1997). The middle Miocene La Venta fauna is one of the few diverse Cenozoic vertebrate faunas in tropical South America ( Fig.…”

Late Burdigalian (Miocene) age for pectinids (Mollusca-Bivalvia) from the Pirabas Formation (northern Brazil) derived from Sr-isotope (87 Sr/86 Sr) data

“…Dating by strontium isotope stratigraphy (BRYANT et al 1992-, -) gave an estimated age of 18.3 -18.9 Ma for the upper part of the Chipola Fm of northwestern Florida (17.5 to 18.3 Ma recalculated to NIST987 0.710248 and the LOWESS 5 calibration of McArthur et al 2012). These recalculated ages are also Burdigalian but are slightly older than our ages for parts of the Pirabas Fm.. MORENO et al (2015) and HENDY et al (2015) presented 87 Sr/ 86 Sr ages from 17.45 to 17.51 Ma (Burdigalian) for the Jimol Fm. (Northern Colombia).…”

A New Early Miocene (Aquitanian) Elasmobranchii Assemblage from the la Guajira Peninsula, Colombia

“…1), and provides an extensive and well-exposed sedimentary and paleontological record of the last 30 million years (Ma) Moreno et al 2015). Recent expeditions to the La Guajira Peninsula (Cocinetas Basin) brought about the extensive surface collection of vertebrate fossils, including the chondrichthyan assemblage from the early Miocene (Aquitanian) Uitpa Formation reported here.…”

“…Reports on marine chondrichthyans from the Miocene of Colombia are scarce in the literature and previous works on the Cocinetas Basin (La Guajira Peninsula) only include a brief mention of elasmobranch fossils with no accompanying taxonomic description by Lockwood (1965) and a list of 14 families presented in Moreno et al (2015).…”

“…"Southern South America" is a region composed of the southernmost areas of South Figure 2. Generalized stratigraphy of the Cocinetas Basin (after Moreno et al, 2015), including a complete stratigraphic section of the Uitpa Formation and an illustration of the studied outcrop, that corresponds to the lowest 10 stratigraphic meters of the formation. America; namely, Argentina, Chile, Paraguay and Uruguay (south of the Tropic of Capricorn).…”