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Girón Formation
The Girón Formation ( es, Formación Girón, Jg) is an extensive geological formation stretching across from the north in Teorama, Norte de Santander, across the Mesa de Los Santos and Chicamocha Canyon towards west of Nobsa, Boyacá in the northern part of the Altiplano Cundiboyacense in the south. The formation extends across the northern and central part of the Eastern Ranges of the Colombian Andes. The formation forms the basement in the Middle Magdalena Valley and is forming the Serranía de Los Cobardes. The Girón Formation consists of thickly bedded red sandstones, shales, siltstones and conglomerates deposited in a terrestrial alluvial and fluvial to fluvio-lacustrine environment in an extensional basin setting. The formation dates to the Late Jurassic period and has a maximum thickness of at its type locality in the valley of the Lebrija River. Definition The formation was first defined by Hettner in 1892 and named after Girón, close to Bucaramanga, Santander. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age. In the past, ''Malm'' was also used to indicate the unit of geological time, but this usage is now discouraged to make a clear distinction between lithostratigraphic and geochronologic/chronostratigraphic units. Subdivisions The Late Jurassic is divided into three ages, which correspond with the three (faunal) stages of Upper Jurassic rock: Paleogeography During the Late Jurassic Epoch, Pangaea broke up into two supercontinents, Laurasia to the north, and Gondwana to the south. The result of this break-up was the spawning of the Atlantic Ocean. However, at this time, the Atlantic Ocean was relatively narrow. Life forms of the epoch This epoch is well known for many famous types of dinosau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
