Venado Formation
Geological formation in the Colombian Andes / From Wikipedia, the free encyclopedia
Dear Wikiwand AI, let's keep it short by simply answering these key questions:
Can you list the top facts and stats about Venado Formation?
Summarize this article for a 10 year old
The Venado Formation (Spanish: Formación Venado, Oir) is a geological formation of the Agua Blanca Group, in the Eastern Ranges of the Colombian Andes, cropping out along the Venado River in northern Huila. The sequence of pyrite containing dark grey micaceous shales interbedded with siltstones and sandstones dates to the Ordovician period; Middle to Late Floian epoch, and has a maximum thickness of 670 metres (2,200 ft) in the type section.
Venado Formation | |
---|---|
Stratigraphic range: Mid-Late Floian ~475–470 Ma | |
Type | Geological formation |
Unit of | Agua Blanca Group |
Underlies | Saldaña Formation |
Overlies | Basement |
Thickness | up to 670 m (2,200 ft) |
Lithology | |
Primary | Shale |
Other | Siltstone, sandstone, pyrite |
Location | |
Coordinates | 3°13′21.3″N 74°52′01.4″W |
Region | Eastern Ranges, Andes |
Country | Colombia |
Type section | |
Named for | Venado River |
Named by | Villarroel et al. |
Location | Baraya |
Year defined | 1997 |
Coordinates | 3°13′21.3″N 74°52′01.4″W |
Region | Huila |
Country | Colombia |
Thickness at type section | 670 m (2,200 ft) |
The unit is one of the few Early Paleozoic fossiliferous formations of Colombia; many graptolites of the genus Phyllograptus have been found in the Venado Formation. The graptolites are mostly found in the silty beds and indicative of a fair weather environment on a siliciclastic shallow marine platform at the northern edge of Gondwana. The shallow sea where the Venado Formation was deposited ranged into the deeper cold Iapetus and Rheic Oceans, separating the South American continent of the time from Laurentia, Avalonia and Baltica.