Sierra Madre Formation
From Wikipedia, the free encyclopedia
The Sierra Madre Formation is a geologic formation in Chiapas state, southern Mexico. It consists of marine dolomites and limestones. The formation dates to the Middle Cretaceous, spanning from the Aptian of the Early to the Cenomanian of the Late Cretaceous.
Quick Facts Type, Underlies ...
Sierra Madre Formation | |
---|---|
Stratigraphic range: Aptian-Cenomanian ~120–94 Ma | |
Type | Geologic formation |
Underlies | Ocozocoautla Formation |
Overlies | Santiago & San Ricardo Formations |
Thickness | Composite: 2,590 m (8,500 ft) |
Lithology | |
Primary | Marine limestones |
Other | Marine dolomite |
Location | |
Coordinates | 16.8°N 93.4°W / 16.8; -93.4 |
Approximate paleocoordinates | 13.8°N 59.7°W / 13.8; -59.7 |
Region | Chiapas |
Country | Mexico |
Type section | |
Named for | Sierra Madre de Chiapas |
Named by | Gutiérrez Gil |
Year defined | 1956 |
Close
The dolomites, dolomitic breccias and limestones of the formation have been deposited in a lagoonal to estuarine environment and contain many fossil fish, flora and rudists, typical reef-building organisms of the Cretaceous.
The formation rests on top of the Santiago and San Ricardo Formations, and is overlain by the Campanian to Maastrichtian Ocozocoautla Formation. The thickness of a composite section of the formation amounts to 2,590 metres (8,500 ft).