Thermal evolution of the Guyana Shield

• Grant number: 23/14000-4
• Support Opportunities: Scholarships in Brazil - Program to Stimulate Scientific Vocations
• Start date: January 22, 2024
• End date: March 02, 2024
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Umberto Giuseppe Cordani
• Grantee: Erick Mateus Lima de Oliveira
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Thermal Evolution of the Guyana ShieldThe Guyana Shield, located at the northern part of the Amazonian Craton, is formed by an Archean nucleus, with rocks up to 2700 Ma old, included in Proterozoic granitic rocks, with about 2000 Ma old. A huge fault mega-zone, named K'Mudku, crosses the entire region, about 1500 Km long and about 300-400 Km large, with a NE-SW structural trend. Its estimated age is bracketed within 1500 and 1000 MaThe objective of this project is to investigate the thermo-cinematic evolution and the tectonic significance of this mega-zone, which never received detailed studies. Precise geochronological studies are lacking, as well as the relation of the deformation with magmatic episodes. The project will carry out age measurements of deformed and undeformed rocks, using isotopic measurements of material with different closing temperatures. Age determinations with the Rb-Sr method in micas, as well as the Ar-Ar method in micas and amphiboles will be carried out in order to obtain the possible existence of different metamorphic episodes. (AU)