Análise da deformação através de mapas de catodoluminescência e do geotermômetro Ti no quartzo no Granito Capote, no Cinturão Ribeira

• Autor(a) principal: Grella, João Victor
• Data de Publicação: 2022
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/217289
• topic: Ti in quartz; Thermometry; Microtectonic; Ti no quartzo; Termometria; Microtectônica

Quartz is one of the most abundant minerals in the Earth's crust, however, its composition of almost 100% Si has always resulted in few geochemical studies on it. The advancement of trace element analysis techniques has changed this context, and, although the Ribeira Belt is widely studied in terms of its evolutionary aspects, more and more works are emerging focused on analytical techniques to determine the physical conditions of this evolution, which is the objective of this work. The Ti in quartz geothermometer was applied from quantitative analysis of specific concentrations of Ti in a deformed granite and an undeformed granite samples, belonging to the Capote Granite (Tres Córregos Granitic Complex). Cathodoluminescence emission maps, with blue filter, were used to interpret the distribution of Ti contents in quartz. The spot analyzes showed Ti concentrations in quartz of 13.19 µg/g to 46.16 µg/g in the undeformed sample, and 16.19 µg/g to 42.56 µg/g in the deformed sample, which were applied to the Ti thermometer in quartz, under pressure estimates at 5 kbar, resulted in temperatures between 534 to 633°C, with an average of 558°C, and 546 to 625°C, with an average of 567°C. For the undeformed sample, the highest concentrations of Ti in quartz were identified in the centers of the crystals, which is correlated with the residence time of the rock in the magmatic system, in contrast, the deformed sample presented the highest concentrations of Ti near the edges of the crystals of quartz, which is correlated with the effect of recrystallization mechanisms, mainly the grain boundary migration at higher temperature, which causes fluidization in the boundary region of the grains, turning them into bands of movement and reconcentration of trace elements.