Achala Batholith
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The Achala Batholith (Spanish: batolito de Achala) is a group of plutons in the Sierras de Córdoba in central Argentina. With a mapped surface of over 2,500 square kilometres (970 sq mi) it constitutes the largest group of intrusions exposed in the Sierras Pampeanas.[1][2] The oldest reference to the batholith dates to 1932.[1]
Plutons intrude into older migmatites, metamorphic rocks of sedimentary and volcanic protoliths.[1][3] Some specific intruded rock types are: biotite-bearing tonalitic gneisses, amphibolite, marble and quartzite.[1]
In the large-scale the intrusion is parallel to the schistosity of the older rocks. However, at smaller scales, the intrusion seems to disregard schistisity.[3] Host rocks are altered contact metamorphism and associated fluids. Alteration is seen in the occurrence of marble and minerals such as vesuvianite and humite, both of which are high on fluorine. This alteration is thought to also have affected the batholith itself.[4]