Paleoenvironmental and diagenetic evolution of the Barremian La Tosca Member limestones, Neuquén Basin, Argentina

• Grant number: 25/05644-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2025
• End date: April 30, 2027
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Andre Luiz Silva Pestilho
• Grantee: Santiago Centorbi
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 24/05057-5 - METALTRAP: New geochemical and geochronological proxies for the discovery of the carbonate-hosted Zn-Pb deposits, AP.R

Abstract

This study aims to reconstruct the paleoenvironmental and diagenetic history of the Late Barremian La Tosca Member of the Huitrín Formation, Neuquén Basin, Argentina. The Neuquén Basin, a significant petroleum province in South America, has a complex geological evolution shaped by subsidence, marine transgressions, and volcanic activity. The Huitrín Formation records the transition from continental to marginal-marine environments and serves as a key archive of Early Cretaceous paleoclimatic and tectonic changes. Within this formation, the La Tosca Member consists of partially dolomitized marine limestones, offering valuable insights into the paleoclimatic and diagenetic processes associated with Andean uplift. Despite previous studies on the formation's depositional and paleontological aspects, an integrated analysis of its diagenetic evolution remains unexplored. To address this gap, the research aims to: (i) reconstruct the paleoenvironmental evolution of the La Tosca Member; (ii) determine the timing and sequence of diagenetic events; (iii) analyze and interpret stable isotope compositions (C, O, and S); (iv) define the primary controls on porosity and permeability distribution; and (v) deliver an integrated geological framework. These objectives will be achieved through a multidisciplinary methodology, including facies analysis, petrography (optical, UV epifluorescence, cathodoluminescence, SEM/EDS), confocal micro-laser Raman spectrometry, and stable isotope geochemistry. The findings are expected to enhance our understanding of Andean geological evolution, refine diagenetic models for carbonate reservoirs, and provide insights into dolomitization processes applicable to offshore carbonate reservoirs, such as those in the Pre-Salt province. This study aims to contribute significantly to the fields of sedimentology, diagenesis, and reservoir characterization.