Banca de DEFESA: LUANA RIBEIRO GARCIA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LUANA RIBEIRO GARCIA
DATE: 20/03/2025
TIME: 09:00
LOCAL: PPGMEG
TITLE:

SUCCESSIVE MESOCENOZOIC RUPILE REACTIVATIONS IN A NEOPROTEROZOIC MILLONITIC SHEAR ZONE

KEY WORDS:

Reactivation, Shear Zone, Cenozoic, Faults, Geomorphic Indices

PAGES: 87
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Geologia
SUMMARY:

Ancient ductile shear zones in an intraplate setting can be reactivated by Cenozoic tectonic events. In the region of São Tomé das Letras and its surroundings (MG), tectonic reactivation has been observed in the Caxambu Shear Zone, whose fault systems, probably associated with Cenozoic tectonic regimes, have exerted a significant influence on the Verde River watershed. The combination of modern techniques, including the application of geomorphic indices, qualitative and quantitative geomorphological analyses, along with geological-structural field data (faults and fractures) and the hierarchical classification of tectonic events, allowed us to understand the role of Cenozoic tectonics in landscape evolution. Structural trends were identified, representing fault systems mapped in the field. The structural data were organized into six brittle tectonic events, from the oldest to the most recent: NE-SW compression, sinistral transpression NE-SW and E-W, NW-SE extensional phase associated with the rift system of southeastern Brazil, followed by two dextral strike-slip systems (NE-SW), with the most recent one oriented E-W. These events were correlated with geomorphological analyses. The identified drainage patterns and anomalies coincide with fault zones. The applied geomorphic indices (longitudinal profiles, knickpoint distribution, Chi-plot, and drainage divide analysis) also show a correlation with the mapped faults and demonstrate that the Verde River watershed was previously compartmentalized into two sectors, south and north of the quartzite ridge. Fault systems facilitated the connection of segments through drainage capture, leading to the watershed's current configuration. Moreover, structural data indicate that the main framework of the Neoproterozoic basement, the Caxambu Shear Zone, has been reactivated as a brittle structure since at least the Cretaceous.

COMMITTEE MEMBERS:
Externo à Instituição - EDUARDO SALAMUNI - UFPR
Presidente - 1168803 - CLAUZIONOR LIMA DA SILVA
Externa à Instituição - JESSICA MIRANDA DOS SANTOS - UFPR
Externo à Instituição - ROBERTO MARQUES NETO - UFJF