The Andean Batholith and the Southeast Asian Tin-Belt Granites Compared

Abstract

The Andean Batholith of Peru consists of about 1,000 interlocking plutons and can be subdivided into plutons, super-units, and batholithic segments. The primary level is that of the pluton which may be internally zoned by pulses and surges of related magma. Chains of plutons of identical lithology, which have consistent intrusive relationships to other members of the batholith, are referred to as super-units. The batholithic segment consists of a very large area of the batholith which is comprised of a specific number of super-units. Five segments have been recognised but only two have been mapped in detail: the Lima segment 400 km long and the Arequipa segment 1,000 km long. Although the lithological composition of the two segments is similar and ranges from gabbro to monzogranite, the plutons of the Arequipa segment are relatively enriched in K20 and the segment is also more intensely mineralised with copper and base metals.