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

Federico Moreno ,S Zapata,D S Jones,D Delgado-Sierra,María Camila Vallejo-Pareja ,Edwin‐Alberto Cadena ,Camila Mártinez ,Luis Quiroz ,Gustavo A Ballen ,Camilo Montes ,Austin J.w Hendy ,R.d Sánchez ,Nicholas D Perez ,Natalia Hoyos ,Jaime Escobar ,Juan D Carrillo ,Vladimir Zapata ,José I Martínez ,C Cadarso Suárez ,Andrés Cárdenas ,Joëlle Anne Moreno ,Jorge D Carrillo-Briceño ,César A Jaramillo

doi:10.1007/s13358-015-0071-4

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) the description of a new lithostratigraphic unit, the Ware Formation (Late Pliocene). We conducted extensive fieldwork to develop a basin-scale stratigraphy, made exhaustive paleontological collections, and performed 87Sr/86Sr geochronology to document the transition from the fully marine environment of the Jimol Formation (ca. 17.9–16.7 Ma) to the fluvio-deltaic environment of the Castilletes (ca. 16.7–14.2 Ma) and Ware (ca. 3.5–2.8 Ma) formations. We also describe evidence for short-term periodic changes in depositional environments in the Jimol and Castilletes formations. The marine invertebrate fauna of the Jimol and Castilletes formations are among the richest yet recorded from Colombia during the Neogene. The Castilletes and Ware formations have also yielded diverse and biogeographically significant fossil vertebrate assemblages. The revised lithostratigraphy and 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.

Highlights

Cenozoic pull-apart sedimentary basins are common along the northern edge of the South American continent as a consequence of the interaction between the South American and Caribbean plates (Muessig 1984; Pindell 1991; Zapata et al 2014)
The Jimol, Castilletes, and Ware Formations record the paleoenvironmental transition of the Cocinetas Basin from a shallow marine shelf to a fluvio-deltaic system
New stratigraphic and geochronological data result in a revised definition of the Neogene lithostratigraphic units in the Cocinetas Basin

Summary

Introduction

Cenozoic pull-apart sedimentary basins are common along the northern edge of the South American continent as a consequence of the interaction between the South American and Caribbean plates (Muessig 1984; Pindell 1991; Zapata et al 2014). Biostratigraphic data based on micropaleontology (Becker and Dusenbury 1958; Burgl 1960; Lockwood 1965; Renz 1960; Rollins 1965; Zapata 2010) and macropaleontology (Olsson and Richards 1961; Rollins 1965; Thomas 1972) have been previously reported Most of these studies are taxonomically outdated, lack of systematic analysis, and are based on Stratigraphy of the Cocinetas Basin, Colombia

Methods

Discussion

Conclusion