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Simijaca Formation
The Simijaca Formation (, K2S, Kss) is a formation (geology), geological formation of the Altiplano Cundiboyacense, Cordillera Oriental (Colombia), Eastern Ranges of the Colombian Andes. The predominantly mudstone formation dates to the Late Cretaceous period; Turonian and Cenomanian epochs, and has a maximum thickness of . Etymology The formation was defined and named in 1991 by Ulloa and Rodríguez after Simijaca, Cundinamarca Department, Cundinamarca.Montoya & Reyes, 2005, p.21 Description Lithologies The Simijaca Formation is characterised by a sequence of mudstones, grey and black shales with sandstone and limestone intercalations. Stratigraphy and depositional environment The Simijaca Formation conformably overlies the Chiquinquirá Sandstone, and the Hiló Formation, Hiló and Pacho Formations, and is overlain by the La Frontera Formation.Acosta & Ulloa, 2001, p.32 The age has been estimated to be Turonian, or Cenomanian.Acosta & Ulloa, 2001, p.41 Stratigraphically, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cenomanian
The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretaceous series (stratigraphy), Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding age. Both age and stage bear the same name. As a unit of geologic time measure, the Cenomanian Age spans the time between 100.5 and 93.9 million years ago (Mya). In the geologic timescale, it is preceded by the Albian and is followed by the Turonian. The Upper Cenomanian starts around at 95 Mya. The Cenomanian is coeval with the Woodbinian of the regional timescale of the Gulf of Mexico and the early part of the Eaglefordian of the regional timescale of the East Coast of the United States. At the end of the Cenomanian, an anoxic event took place, called the Cenomani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |