The palynology of the Cerrejón formation (Upper Paleocene) of northern Colombia

Abstract

A palynological study of the Cerrejon Formation was conducted in order to date the formation and understand the floristic composition and diversity of a Paleocene tropical site. The Cerrejon Formation outcrops in the Cerrejon Coal Mine, the largest open cast coal mine in the world. Two cores (725 m) were provided by Carbones del Cerrejon LLC for study. Two hundred samples were prepared for palynology, and at least 150 palynomorphs were counted per sample where possible. Several statistical techniques including rarefaction, species accumulation curves, detrended correspondence analysis, and Anosim were used to analyze the floristic composition and diversity of the palynofloras. Palynomorph assemblages indicate that the age of the Cerrejon Formation and the overlying Tabaco Formation is Middle to Late Paleocene (ca. 60-58 Ma). Major structural repetitions were not found in the Cerrejon Formation in the Cerrejon coal mine, and there is little floral variation throughout. The floral composition, diversity, and lithofacies do not change significantly. Lithofacies associations and floral composition indicate deposition fluctuating from an estuarine-influenced coastal plain at the base to a fluvialinfluenced coastal plain at the top. There are, however, significant differences in the composition and diversity of coal and siliciclastic samples. Coal palynofloras have fewer morphospecies, and a distinct and more homogeneous floral assemblage compared to assemblages from the intervening sisliciclastic strata, suggesting that tropical swampy environments supported fewer plant species and had a distinct vegetation adapted to permanently wet environments.

Palynostratigraphy and sedimentary facies of Middle Miocene fluvial deposits of the Amazonas Basin, Brazil

“…Various authors (Dueñas, 1980;Monsh, 1998;Jaramillo and Dilcher, 2000;Pardo-Trujillo et al, 2003;Helenes and Cabrera, 2003;Silva, 2004;Jaramillo et al, 2007;Latrubesse et al, 2007) have indicated that the climate in the Amazonia region and north of South America, was, in general, hot and wet during the Middle/Late Miocene. This interpretation is justified by the marked presence of Gramineae, Palmae, and aquatic algae, as well as the presence of crocodilians, which are unequivocal indicators of floodplain environments (Riff et al, 2010).…”

Terrestrial palynology and age assessment of the Gedaref Formation (eastern Sudan)

“…racematus in the studied material) are known from the Oligocene of Cameroon (Salard-Cheboldaeff, 1979) and the Maastrichtian to Oligocene of Sudan (Awad, 1994;Stead and Awad, 2005). South American records are from the Maastrichtian to Eocene ( Van der Hammen, 1954;González Guzmán, 1967;Ravn, 1998;Jaramillo et al, 2007). In addition González Guzmán (1967) and the Taxon database (Ravn, 1998) also mention an undifferentiated Upper Cretaceous occurrence (not included in Fig.…”

“…Previous records of Retidiporites magdalenensis are from the Maastrichtian of Nigeria, Egypt, Somalia (Lawal and Moullade, 1986;Schrank, 1987Schrank, , 1994a, the Maastrichtian to Paleocene of Nigeria (Germeraad et al, 1968; and Sudan (Awad, 1994) and the interval Maastrichtian to Eocene of the Caribbean (Germeraad et al, 1968), Colombia (Jaramillo et al, 2007) and several West African basins (Salard-Cheboldaeff, 1990). Retidiporites magdalenensis (together with Monocolpites marginatus) is regarded by Lawal and Moullade (1986, p. 72) as a Maastrichtian marker.…”

“…All African and South American occurrences are in the Maastrichtian-Eocene age range (e.g. González Guzmán, 1967; Adegoke et al, 1978;Salard-Cheboldaeff, 1979;Jaramillo et al, 2007) thus supporting an age not older than Maastrichtian for the studied material. Similar ages have been reported for the Caribbean (Maastrichtian to Mid Eocene, inconsistently to Pliocene), Nigeria (Paleocene to Late Eocene) and Borneo (Paleocene) by Germeraad et al (1968) as well as for West African basins (Paleocene-Eocene) by Salard-Cheboldaeff (1990).…”

Health interventions used by major resource companies operating in Colombia

“…About 35% of its population is illiterate and 65.2% fail to have their basic needs met (Departamento Nacional de Planeación -DNP, 2014). Contributing to about 60% of La Guajira's gross domestic product (Balch 2013), Cerrejón is the largest producer of coal in Colombia, and the biggest open pit coal operation in the world (Jaramillo et al 2007). It is a joint venture owned by BHP Billiton, Anglo American and Xstrata Coal, in operation since 1976.…”