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Macarao Formation
The Macarao Formation ( es, Formación Macarao, E2m) is a formation (geology), geological formation of the Cocinetas Basin in the northernmost Colombian departments of Colombia, department of La Guajira Department, La Guajira. The formation consists of foraminifera-rich fine to medium grained calcareous sandstones intercalated with calcareous siltstones, cross-cut by veins of gypsum. The thick Macarao Formation dates to the Paleogene period; Eocene, Middle to Late Eocene epoch, corresponding to the Divisaderan in the South American land mammal ages (SALMA). Definition The formation was defined by Rollins in 1965.Moreno et al., 2015, p.7 Description Lithologies The Macarao Formation consists of foraminifera-rich fine to medium grained calcareous sandstones intercalated with calcareous siltstones, cross-cut by veins of gypsum.Plancha 10bis, 2008 Stratigraphy and depositional environment The Macarao Formation has a maximum thickness of and overlies the Cretaceous Guaramala ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope Carbon-13, 13C in the atmosphere was exceptionally low in comparison with the more common isotope Carbon-12, 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Popigai impact structure, Siberia and in what is now ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
