Abstract:
We present major, trace and Sr isotopic data of feldspar crystals from various intrusions within the potassic Ponte Nova Mafic-Ultramafic Alkaline Massif (PNAM; 86.7 Ma), which exhibit varying degrees of contamination by the crustal country rock. Additionally, we provide compositional data of biotite, amphibole, ilmenite, and magnetite from the PNAM. We also include data of a few feldspars and biotite crystals of the country rock, which comprises a Precambrian calc-alkaline granite from the Serra da Água Limpa batholith. The crystals in 30- to 120-µm polished thin sections were analyzed using EMP, LA-ICP-MS, LA-MC-ICP-MS, and TIMS. Prior to analysis, chemical zonings, resorption features, and mineral inclusions were identified through optical and scanning electron microscope to ensure their avoidance during analysis.
User Contributed Keyword(s):
mineral chemistries, crustal assimilation, magmatic recharge, alkaline rocks