Banca de QUALIFICAÇÃO: GILSIJANE VIEIRA RAMOS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : GILSIJANE VIEIRA RAMOS
DATE: 23/09/2021
TIME: 14:00
LOCAL: videoconferência
TITLE:

Influence of basement on fault nucleation and characterization of the internal architecture of the Rio do Peixe Basin (RPB)

KEY WORDS:

Structural inheritance; Basement-controlled reactivation; Brittle fault reactivation; Fault nucleation; Intracontinental rift basins; seismic and magnetic data.

PAGES: 77
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUMMARY:

The formation of sedimentary basins influenced by the reactivation of preexisting structures is a topic of intense debate in the scientific community, in which preexisting shear zones can strongly influence evolution, induced by mechanical and rheological heterogeneities. Although a 3-D geometric relationship offers some insight into how basement structures control the overall geometry and spatial development of rift-related faults, the control of normal faults growth, like the result of interaction between pre-existing shear zones and younger rift faults, is poorly understood. This research integrates aeromagnetic, 2-D and 3-D seismic reflection data with geological field data to show that the reactivation of weak basement fabric in RPB represents an inheritance of the heterogeneous basement deformation, influencing fault nucleation and basin’s internal architecture. The interpretation of geophysical data allowed the identification of ductile basement structures beneath the BRP and the brittle reactivations along the basin, where we infer that: (a) the Precambrian fabric acted as a nucleation site for the faults in the initial fault development; (b) basin-bounding fault reactivation occurs along shear zones that separate major terrains; (c) although the Precambrian ductile shear zones and the younger brittle faults share similar strike, the latter cross-cut the Precambrian fabric at depth (different dips); (d) tectonic inheritance from basement structures induce long-lived brittle reactivation. Here we show that the spatial coincidence of Precambrian ductile shear zones and brittle faults is not trivial, as despite being parallel along the direction, the dip of these structures diverges, suggesting that the geometry of rift faults is not fully controlled by tectonic inheritance of pre-existing structures in the Precambrian basement.

BANKING MEMBERS:
Externo à Instituição - KLEDSON TOMASO PEREIRA DE LIMA - PETROBRAS
Presidente - 1315614 - DAVID LOPES DE CASTRO
Externo à Instituição - FRANCISCO CEZAR COSTA NOGUEIRA - UFCG
Externo à Instituição - PEDRO XAVIER NETO - PETROBRAS