Swiss J Palaeontol (2015) 134:45–75 DOI 10.1007/s13358-015-0074-1 Neogene molluscs, shallow marine paleoenvironments, and chronostratigraphy of the Guajira Peninsula, Colombia 1,2 2 3,4,5 3,6 Austin J. W. Hendy • Douglas S. Jones • Federico Moreno • Vladimir Zapata • Carlos Jaramillo3 Received: 6 January 2015 / Accepted: 30 March 2015 / Published online: 9 June 2015 Ó Akademie der Naturwissenschaften Schweiz (SCNAT) 2015 Abstract The Neogene sedimentary fill of the Cocinetas and Ware formations found in Cocinetas Basin. The basal Basin in northern Colombia preserves a rich record of unit in the Neogene succession, the Uitpa Formation, marine invertebrates and can be analyzed in the context of comprises mudstones redeposited sandstones and molluscs a high-resolution stratigraphy and excellent chronostratig- typical of bathyal to outer shelf environments at its base. It raphy. Molluscan fossils are highly diverse and often well is a shallowing-up sequence and is conformable with the preserved, offering a window into the rapidly changing overlying Jimol Formation, which comprises coarse- paleoenvironments and biogeography of northern South grained lithic calcarenite, coquina, and mudstone that America during parts of the Early to Middle Miocene and represent a regressive–transgressive–regressive sequence. latest Pliocene to Pleistocene. Before the evolutionary and This sequence includes foreshore and transition zone biogeographic implications of these fossils can be under- through lower inner shelf environments, but generally stood, however, their associated depositional environments poorly preserved invertebrate assemblages. The con- and geologic ages must be determined. Here, we present formably overlying Castilletes Formation contains a varied preliminary results from paleoenvironmental, biostrati- suite of depositional environments with better-developed graphic, and strontium isotope chronostratigraphic analyses shell beds and thicker successions of intervening siltstone. of sediments and fossils from the Uitpa, Jimol, Castilletes, A significant unconformity exists between the Castilletes Formation and the overlying Ware Formation, which rep- resents a deltaic to coastal shoreface deposition environ- ment, rich in shallow marine molluscs from a variety of ecotopes. Biostratigraphic assessment and strontium iso- topic results from the Jimol and Castilletes formations indicate that these units contain fossils of latest Early Electronic supplementary material The online version of this Miocene through Middle Miocene age, while those of the article (doi:10.1007/s13358-015-0074-1) contains supplementary material, which is available to authorized users. Ware are approximately Late Pliocene in age. These results help to place the shallow marine assemblages of Cocinetas & Austin J. W. Hendy Basin into a wider geologic context that aids our under- [email protected] standing of how these faunas relate to the broader evolu- 1 Natural History Museum of Los Angeles County, tionary and biogeographic history of the southern Los Angeles, USA Caribbean during the Neogene. Additionally, the isotope 2 dating and paleoecology of this fauna help to place co- Florida Museum of Natural History, University of Florida, Gainesville, USA occurring terrestrial and aquatic vertebrate assemblages into a local paleoenvironmental and chronostratigraphic 3 Smithsonian Tropical Research Institute, Panama, USA framework. 4 University of Rochester, Rochester, NY, USA 5 Corporacio´n Geolo´gica ARES, Bogota´, Colombia Keywords Jimol Formation Á Castilletes Formation Á 6 Ecopetrol S.A., Bogota´, Colombia Ware Formation Á Mollusca Á Guajira Peninsula Á Colombia 46 A. J. W. Hendy et al. Introduction formations. Both Olsson and Richards (1961) and Thomas (1972), as well as Bu¨rgl (1960), Renz (1960) and Rollins Marine invertebrate paleontology of Cenozoic sediments (1960, 1965) barely scratch the surface of the tremendous on the Guajira Peninsula of Colombia has received fossil biodiversity captured in the strata of the Guajira relatively little attention, despite substantial interest in the Peninsula, and none of these works explored fully the po- stratigraphy and tectonic features of the region and the tential of these fossils for biostratigraphic or paleoenvi- extensive paleontological research that has been conducted ronmental analysis. in the neighboring sedimentary basins of northern The Neogene fossil record in the Cocinetas Basin is Venezuela (Jung 1965; Landau and Marques da Silva particularly well exposed and offers the opportunity to 2010) and southern Caribbean Islands (e.g., Jung 1969). document more fully the biodiversity and biogeography of The Cocinetas Basin on the eastern flank of La Guajira the southern Caribbean and northern South America during Peninsula, northern Colombia (Fig. 1a), provides an ex- two intervals: the Early to Middle Miocene and the Late tensive and well-exposed sedimentary and paleontological Pliocene (Moreno et al. 2015). Similar Miocene faunas record of the last 30 million years. The only published (Fig. 1a) include the Culebra Formation of Panama (e.g., work that has dealt specifically with fossil marine inver- Woodring 1957), the very diverse Cantaure Formation on tebrate systematics and biostratigraphy of the Guajira re- the Paraguana Peninsula (Jung 1965), the La Rosa, Agua gion is a short paper on molluscs from the Macarao Clara, Querales, and Socorro formations in the Falco´n (Eocene) and Siamana (Oligocene) formations by Olsson Basin (Hodson 1926; Hodson et al. 1927; Hodson and and Richards (1961), which had a poor stratigraphic control Hodson 1931a, b; Johnson et al. 2009; Quiroz and and geographic accuracy. More comprehensive systematic Jaramillo 2010) in Venezuela, Early Miocene strata of research was undertaken by Thomas (1972) in the form of Trinidad (Maury 1912; Jung 1969) and the Baitoa For- an unpublished dissertation, which focused primarily on mation of the Dominican Republic (e.g., Maury 1917; molluscs, presumably from either the Jimol or Castilletes Saunders et al. 1986). Correlated Pliocene faunas (Fig. 1) may be found in the Cayo Agua Formation of Panama A (Olsson 1922), San Gregorio Formation of Falco´n Basin 13 7 (Hodson et al. 1927; Hodson and Hodson 1931a, b), Mare 12 and Playa Grande formations of eastern Venezuela (Weisbord 1962, 1964a, b), Araya Formation of Cubagua Caribbean Plate Island (Landau and Marques da Silva 2010), Bowden Formation of Jamaica (Woodring 1925, 1928), and Mao Limestone of the Dominican Republic (Saunders et al. 5 Study area 1986). Nevertheless, with the exception of the Dominican inset 9 Republic, none of these faunas have been studied within 3 11 2 4 10 6 the context of well-developed stratigraphy and independent 8 1 South American Plate chronostratigraphic framework. Extensive new fieldwork in Cocinetas Basin, including Guajira Cocinetas B Pen. Basin Important geological mapping, lithofacies description, and extensive Paraguana faunas Cuiza F. Peninsula and systematic collection of marine and terrestrial inver- 1 Early-Middle Ocu F. Falcon Miocene tebrates has been conducted since 2011. The present paper Basin 7 Late Pliocene builds on a revised stratigraphy for the Neogene sedimentary fill of Cocinetas Basin by Moreno et al. (2015). We provide a detailed chronostratigraphic frame- Fig. 1 a Location of Cocinetas Basin in the Guajira Peninsula of work derived from 87Sr/86Sr isotopic analyses and describe northern Colombia and other important Early-Middle Miocene (Bur- digalian–Langhian) and Late Pliocene units in the southern the biodiversity, biostratigraphy, and paleoenvironmental Caribbean: 1 upper Culebra Formation (Panama), 2 La Rosa significance of nearly 250 field localities (c. 8000 speci- Formation (Venezuela), 3 Agua Clara, Querales, and Soccoro mens) collected or surveyed during this recent fieldwork formations (Venezuela), 4 Castillo Formation (Venezuela), 5 Can- and from historic collections. taure Formation (Venezuela), 6 Brasso and Manzanilla formations (Trinidad and Tobago), 7 Baitoa Formation (Dominican Republic), 8 Cayo Agua Formation (Panama), 9 San Gregorio Formation Geological setting (Venezuela), 10 Mare and Playa Grande formations (Venezuela), 11 Araya Formation (Venezuela), 12 Bowden Formation (Jamaica), 13 Cocinetas Basin, located on the southeast Guajira Penin- Mao Limestone (Dominican Republic). b Map of northern Colombia and Venezuela showing location of Cocinetas Basin in the context of sula (Fig. 1b), is one of many pull-apart sedimentary basins major regional faults found along the northern margin of South America Neogene molluscs, shallow marine paleoenvironments… 47 Macuira Range 70°30’ W Siapana Jarara Range A 12° N 12° N D C Key F Quaternary Puerto Lopez Ware Fm G Caslletes Fm Bahia Tortugas Jimol Fm H Uipta Fm Siamana Fm Cocinas Macarao Fm Range Cretaceous E Caslletes Pre-Cretaceous Sample locality 10 km Town/village 70°30’ W Bahia Cocinetas Flor de Guajira B Fig. 2 Geological map of southeastern Cocinetas Basin showing distribution of sedimentary units, sampling localities, and points of interest. These include a Arroyo Uipta, b Patsu´a, c Paraguacho´n, d Patajau, e Kaitamana, f Yotohoro, g Bahia Tucacas, h Macaraipao (Muessig 1984; Pindell and Barrett 1990; Macellari 1995). The southern, western, and northern boundaries are de- Renz Rollins Moreno Epoch Stage limited by the Cocinas (coincident with Cuiza Fault), Jar- (1960) (1965) et al. (2014) ara, and Macuira ranges, respectively (Fig. 2). Deposition Age (Ma) Age (Ma) Late Piacenzian Ware