The Vicuña Mackenna Batholith ( es, Batolito Vicuña Mackenna) is a group of
pluton
In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...
s in the
Chilean Coast Range
The Chilean Coastal Range ( es, Cordillera de la Costa) is a mountain range that runs from north to south along the Pacific coast of South America parallel to the Andean Mountains, extending from Morro de Arica in the north to Taitao Peninsula, ...
of
northern Chile. The plutons of the
batholith
A batholith () is a large mass of intrusive igneous rock (also called plutonic rock), larger than in area, that forms from cooled magma deep in Earth's crust. Batholiths are almost always made mostly of felsic or intermediate rock types, such ...
formed (cooled from
magma to rock) between the
Early Jurassic and the
Late Cretaceous (192–98
Ma). The
magmas that formed the batholith originated in
Earth's mantle and have not suffered any significant
crustal contamination. A group of Early Cretaceous plutons were intruded
syn-tectonically on the
Atacama Fault.
Subdivision
Geologists Miguel Hervé and Nicolás Marinivic identify six major units. From the oldest to the youngest these are:
[
* Barazate Unit (192-181 Ma)
* Paranal Unit (ca. 170 Ma). This unit has the largest areal extent. It is composed of gabbronorite, gabbro, diorite, ]monzodiorite Monzodiorite is an intrusive rock with a composition intermediate between diorite and monzonite. It is defined in the QAPF classification as coarse-grained igneous rock in which quartz makes up 0% to 5% of the QAPF mineral fraction, plagioclase
...
, monzogabbro Monzogabbro is an intrusive rock with a composition intermediate between gabbro and monzonite. It is defined in the QAPF classification as coarse-grained igneous rock in which quartz makes up 0% to 5% of the QAPF mineral fraction, plagioclase
...
and monzogabbronorite.
* Ventarrones Unit (149-138 Ma)
* Remiendos Unit (133-128 Ma)
* Herradura Unit (108-98 Ma)
See also
* Coastal Batholith of Peru The Coastal Batholith of Peru ( es, Batolito costero peruano) is a group of hundreds, if not thousands, of individual plutons that crop out near or at the coast of Peru. The batholith runs a length of ca. 1600 km. Most of the plutons of the bat ...
References
Batholiths of South America
Lithodemic units of Chile
Geology of Antofagasta Region
Geology of the Chilean Coast Range
Jurassic Chile
Cretaceous Chile
Jurassic magmatism
Cretaceous magmatism
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