Banca de QUALIFICAÇÃO: LUANA SOUSA DA SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : LUANA SOUSA DA SILVA
DATE: 17/07/2026
TIME: 08:00
LOCAL: Videoconferência via Google Meet
TITLE:

Epigenic karst evolution and tufa precipitation in the Potiguar Basin: Structural and  stratigraphic controls in continental carbonate deposits

KEY WORDS:

Epigenic karst; Calcareous tufa; Inception horizon; Karstified reservoir; Carbonate reservoir analog.

PAGES: 65
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Geologia
SUMMARY:

Continental carbonate deposits, such as tufas, are high-resolution paleoenvironmental archives. While  their geometries often reflect paleohydrology, the genetic link between subterranean karst dissolution  networks and surface carbonate precipitation remains poorly constrained. This study investigates this  dynamic in the Potiguar Basin, northeastern Brazil, using a multiscale approach that integrates remote  sensing, UAV photogrammetry, LiDAR, field mapping, petrography, and cathodoluminescence (CL).  Regional mapping reveals that tufa deposits are structurally controlled, nucleating over an epigenic  karst network guided by reactivated fracture corridors and the mechanical stratigraphy of the Jandaíra  Formation along the Apodi-Mossoró incised valley. High-resolution 3D models of the Urubu and  Sicários cave systems capture the critical transition from structurally confined groundwater flow to  turbulent subaerial discharge. Furthermore, petrographic and CL analyses reveal how local  geomorphology strictly dictates facies distribution and diagenetic heterogeneity. The high-energy  Sicários system developed a stepped cascade architecture stabilized by early meteoric cementation,  whereas the lower-energy, confined Urubu pool-barrage system is dominated by rhythmic laminated cements. We demonstrate that Potiguar Basin tufas are not isolated geomorphological features, but  rather the terminal exokarst expressions of a continuous regional fluid-routing network and robust  markers of subaerial exposure. This framework successfully links structurally localized dissolution in  the subsurface of the Jandaíra Formation to the surface tufa depositional architecture. Ultimately, it  provides a highly predictive outcrop analog for understanding facies distribution and diagenetic  heterogeneity in complex, fractured carbonate reservoirs.

COMMITTEE MEMBERS:
Externo à Instituição - PHILIPPE AUDRA
Externo à Instituição - Augusto Sarreiro Auler - INSC
Externo à Instituição - FRANCISCO WILLIAM DA CRUZ JUNIOR - USP
Presidente - ***.785.944-** - VINCENZO LA BRUNA - NÃO INFORMADO