Trincheras Formation

Trincheras Formation
Stratigraphic range: Early Aptian
~120–115 Ma
TypeGeological formation
Unit ofVilleta Group
Sub-unitsAnapoima Mb., El Tigre Mb.
UnderliesSocotá Fm., El Peñón Fm.
OverliesMurca Fm., La Naveta Fm., Útica Fm.
Thicknessup to 1,260 m (4,130 ft)
Lithology
PrimaryShale
OtherSandstone, limestone
Location
Coordinates4°30′13″N 74°36′22″W / 4.50361°N 74.60611°W / 4.50361; -74.60611
RegionAltiplano Cundiboyacense
Eastern Ranges, Andes
Country Colombia
Type section
Named forQuebrada Trincheras
Named byCáceres & Etayo
LocationApulo
Year defined1969
Coordinates4°30′13″N 74°36′22″W / 4.50361°N 74.60611°W / 4.50361; -74.60611
RegionCundinamarca
Country Colombia

Paleogeography of Northern South America
120 Ma, by Ron Blakey

The Trincheras Formation (Spanish: Formación Trincheras, Kitr) is a geological formation of the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The formation consisting of a lower unit of calcareous shales and an upper sequence of shales dates to the Early Cretaceous period; Early Aptian epoch and has a maximum thickness of 1,260 metres (4,130 ft). The formation, deposited in a marine platform environment, part of a transgressive cycle, hosts ammonite, bryozoan, mollusc and echinoid fossils.