Cura-Mallín Group
From Wikipedia, the free encyclopedia
Cura-Mallín Group (Spanish: Grupo Cura-Mallín) is a heterogeneous group of volcano-sedimentary formations of Oligocene-Miocene age, Colhuehuapian to Laventan in the SALMA classification, in south-central Chile and nearby parts of Argentina.[1][2][3] The sediments belonging to the group were deposited in a lacustrine environment and alongside rivers in an intra-arc basin.[1] Southeast of Laguna del Laja Cura-Mallín Group has a thickness of more than 1,800 metres (5,900 ft).[4] The sediments making up the group deposited in an interval between 22 and 8 million years ago.[3]
Cura-Mallín Group | |
---|---|
Stratigraphic range: Upper Oligocene–Middle Miocene Colhuehuapian-Laventan (SALMA) | |
Type | Geological group |
Unit of | Cura-Mallín Basin Neuquén Basin |
Sub-units | Various schemes, see text |
Underlies | Cajón Negro Formation Trapa Trapa Formation |
Overlies | Cretaceous granitoids Jurassic sediments |
Thickness | >1,800 m (5,900 ft) |
Lithology | |
Primary | Sandstone, siltstone, shale, breccia, andesite lava |
Other | Grainstone |
Location | |
Coordinates | 37.7°S 71.2°W / -37.7; -71.2 |
Approximate paleocoordinates | 38.3°S 66.4°W / -38.3; -66.4 |
Region | Araucanía & Bío Bío Regions Neuquén Province |
Country | Chile Argentina |
Type section | |
Named for | Mallín |
The outcrops of Cura-Mallín Group are found along a north-south elongate area.[4] The group is considered an equivalent of Abanico Formation, either as a southern extension or as a lateral equivalent of that formation.[4]