Petrographic, compositional and structural characterization of mafic minerals associated with kimberlite and kamafugite intrusions of Cretaceous ages from the Alto Paranaíba Alkaline Province

Abstract

The progressive evolution of petrological knowledge and the methodological advances of the last decade have contributed significantly to the study of igneous petrology at submicroscopic microscopic scales, allowing the identification of processes and mechanisms. In this sense, detailed petrographic observations and textural and compositional interpretations have been shown to be fundamental for solving petrological problems related to the evolution of magmas and their complex emplacement systems. For kimberlitic and kamafugitic rocks, several recent works have questioned the initial criteria for genetic classification between cognate and xenocrystal phases. The geological, mineralogical and petrological investigations of kimberlites and kamafugites make it possible to know the mechanisms that generate these associations and the evolutionary sequence of these rocks, the physicochemical conditions at the time of their formation, the genetic and geotectonic framework in the context region, as well as the depth and the processes of magma generation, and the nature of the mantle source region. In addition, their study provides important information that supports research on the evolution of the lithospheric and tectonic mantle of the cratonic segments. The main objective of this project is to contribute to the improvement and higher qualification of undergraduate students through the mineralogical study of mafic minerals in the main assembly related to alkaline-prone igneous bodies, mainly mantle xenocrysts, having as main targets the occurrences of kimberlites and kamafugites from the Alto Paranaíba Province. Petrography and mineral chemistry using electron microprobe (wavelength-dispersive spectroscopy - WDS) and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) techniques will be applied to measure major, minor and trace element compositions on the selected crystals. (AU)