Mineralogy of granites from Hukurila area, Ambon Island, Indonesia: An insight into petrogenesis

Abstract

The Hukurila area in the Leitimor region of Ambon Island hosts one of the granite bodies. The granite is surrounded by Jurassic-Cretaceous peridotites. Although granites in Ambon Island have been intensively investigated, their origin remains interesting to study. This work offers petrography and X-ray diffraction data of granite from Hukurila area and contributes to understanding petrogenesis in Ambon Island. Granites from Hukurila area are white to light brown and have a medium- to coarse-grained holocrystalline texture, with quartz, potassium feldspars, plagioclase, biotite, and muscovite being the most common minerals. Potassium feldspars are sometimes found in aggregated larger crystals in the outcrops. While cordierite, zircon, apatite, and mullite were also observed as accessory minerals under the microscope. Mullite in granites from Hukurila area indicates that the rocks were subjected to high temperatures. Aluminium-rich minerals (i.e., cordierite and mullite) in granites from Hukurila area suggest S-type granite with significant crustal contamination during their formation.