Los sedimentos examinados en ambas cuencas revelaron tener una asociación de cocolitos >2% constituida por Gephyrocapsa oceanica, Gephyrocapsa muellerae, Gephyrocapsa <3 μm, Emiliania huxleyi, Calcidiscus leptoporus y Helicosphaera carteri. Los análisis cualitativos y cuantitativos mostraron cambios en las abundancias relativas y en el grado de preservación de los 20 taxones identificados. KEYWORDS: Coccolithophores Colombian Pacific Chocó basin Tumaco basin QuaternaryĮl presente estudio fue llevado a cabo en los cocolitóforos extraídos de 39 piston core perforados en el offshore de las cuencas Chocó y Tumaco, en el Pacífico colombiano. In order to interpret the causes of this variance, we performed a multivariate redundancy analysis (RDA), showing that the distance to the coastline is the controlling factor of the fluctuations of the relative abundances and distribution of the coccoliths in both basins. The number of coccoliths per gram (cc/g) was calculated, demonstrating an average of 5.7x10 6 cc/g and 1.2x10 7 cc/g for Chocó and Tumaco basins, respectively. huxleyi as part of the assemblage indicates that the studied sediments are younger than the biozone NN21, covering an age range of Middle Pleistocene (Ionian).
together with reworked specimens of Reticulofenestra spp, Sphenolithus spp. We also identified a minority assemblage (<2%) constituted by Ceratolithus spp, Coccolithus pelagicus, Florisphaera profunda, Helicosphaera princei, Helicosphaera sellii, Helicosphaera wallichii and Pontosphaera spp. The examined sediments were characterized by the coccoliths Gephyrocapsa oceanica, Gephyrocapsa muellerae, Gephyrocapsa <3 μm, Emiliania huxleyi, Calcidiscus leptoporus and Helicosphaera carteri, which presented abundances higher than 2 %.
Qualitative and quantitative analyses of the coccoliths showed changes in the relative abundances and the state of preservation in the two basins. This study was conducted on coccolithophores recovered from 39 piston-core samples taken offshore Chocó and Tumaco basins, on the Colombian Pacific.