Raman characteristics of gucunkaya (Aksaray) gabbroic rocks, central Anatolia-Turkey

Abstract

The Central Anatolia Basement Units (CABU) have several mafic and felsic characterized magmatic systems which are associated with the closure of the Neotethys during the Late Mesozoic. Gucunkaya gabbro is located to the southern part of Ağaçören Intrusive to the North East of Aksaray in Central Anatolia. Field and petrographic studies show that the mafic products of the area are mainly composed of two main units as a gabro and diorite. The gabbro and the diorite cut by fine crystalline gabbro, diorite porphyry, fine crystalline diorite and diabase dykes. The plagioclases (An51-An93) + hornblende + augite ± quartz ± epidotite ± calcite ± titanite and opaque minerals form the main compositions of the Gucunkaya gabbro, and they are ranging from pyroxene-hornblende gabbro to diorite in composition. The MORB normalized elemental patterns of the gabbro and mafic dykes reveal enrichment in LIL element and depletion in HFS elements. Confocal Raman Spectroscopy (CRS) was investigated from amphibole and plagioclase minerals in the Gucunkaya gabbroic rocks. The CRS studies, was determined that the amphiboles are in the composition of actinolite and the plagioclases are in the composition of labradorite and anorthite. The CRS studies show that actinolites have a Raman shift value of 218.6, 385.76, 531.81, 677.46 and 1046.5 cm-1. The 156.06, 174.02, 221.69, 389.48, 525.06, 668.70, 926.26, and 1055.04 cm-1 values of Raman shift observed in the pyroxene minerals reflected the augite composition. On the bases of petrological, geochemical and spectroscopic data of the research area, the products of the Gucunkaya Gabbroic rocks are derived from the mantle products with depletion of the continental crust. © SGEM2019.