Field Trip

From Life To Rock: Deep Into The Cretaceous Pre-Salt Rift

Saturday, 4 October – Monday, 6 October 2025, 7:30 a.m.–6:00 p.m.  |  Rio de Janeiro, Brazil

Course Content

Our geology field trip provides invaluable first-hand experience that broaden the understanding of the breakup of Gondwana and the formation of the South Atlantic Ocean. Approximately 130 million years ago, during the Cretaceous, tectonic forces caused segmentation and rifting of the Gondwana crust. South America and Africa began to separate forming the oceanic crust and the continental margins below the South Atlantic Ocean. This tectonic event had a profound impact on the geological history of regions such as Região dos Lagos, in Rio de Janeiro, Brazil. It is a unique geological terrane with rock units similar to the Angola craton, in Africa. This rifting process not only dramatically altered the landscape and reshaped the continental margins but also left behind an African crust in the Brazilian coast. In the Búzios area, gneisses formed deep in the lower crust (ca. 60 km), during a Cambrian continental collision (Buzios Orogeny), are exposed due to more than 300 m.y. of exhumation and erosion with subsequent rifting and continental breakup. This metamorphic basement is cross cut by Cretaceous subvolcanic bodies, faults and fractures, prolongated offshore, controlling the most important oil fields of Brazil.

The second part of the study will focus on shallow carbonates and evaporites, further investigating into the depositional environments shaped by the breakup of Gondwana. As the continents drifted apart, a series of lakes formed between them, leading to the accumulation of lacustrine deposits, which play a key role in understanding the region's geology. In Região dos Lagos, modern lakes provided ideal conditions for the formation of microbial carbonates, including stromatolites and thrombolites—important indicators of ancient microbial life and aquatic conditions. Additionally, the presence of primary dolomite in the area adds another layer of significance for carbonate sedimentologists. The combination of these features makes this region especially valuable for studying carbonate diagenesis and sedimentary processes natural analogues to the Presalt reservoir.

Fieldwork in this area offers an exclusive opportunity to develop practical interpretation skills, exposing researchers to diverse geological environments that illustrate the complexities of carbonate and evaporite formation. This hands-on experience strengthens technical knowledge while broadening perspectives, fostering a deeper understanding of geological evolution and sedimentary systems. By immersing themselves in these field experiences, students and researchers gain new insights into the intricate processes that shaped the region, leading to more accurate and comprehensive interpretations of ancient depositional environments and the tectonic evolution of the continents in the southern hemisphere.

Logistic:

Saturday (4th)
Leave Rio at 7:30 to Lagoa Vermelha – Saquarema/RJ
1 – Lagoa Vermelha
2 – Brejo dos Espinhos
3 – Pontal do Atalaia
4- Coquinas de Iguaba
5 –Falha do Bico Preto
Sleep over – Hotel in Buzios/RJ
Sunday (5th)
Leave at 8:00 hotel in Buzios
5 – Costão das Conchas – Cabo Frio
5 – Ponta do Marisco – Geribá – Buzios
6 – Ponta da Lagoinha
7 – Praia do Forno
Sleep over - Búzios
Monday (6th)

Leave at 8:00 hotel in Buzios.
8 – Ponta do Pai Vitório
9 – Morro de São João
Lunch and return to Rio 14:00

Who Should Attend: Geologists and Geophysicists involved in reservoir or exploration interpretation.

Prerequisites: Depositional systems background

Instructors

Renata is a full professor at Federal University of Rio de Janeiro (UFRJ), Brazil, working with geodynamics of convergent tectonic settings, processing mostly structural and geochronological data on Neoproterozoic-Early Paleozoic orogens of Gondwana. Last decade, she has been focusing on prolongating offshore this orogenic mosaic, linking rift processes that generated the South Atlantic continental margins with collisional processes in deep time, a project funded by PETROBRAS. She runs the Gondwana Geoprocessing Digital Centre (GGDC) at UFRJ, with a team of researchers that managed to build up a new geological map of Gondwana at 1:5M scale on GIS, a product of scientific integration with several scientists and institutions around the globe (IGCP-628).

Cris is a geochemist with a strong background in microbiology and a deep expertise in microbial carbonates, integrating stable isotope geochemistry, carbonate sedimentology, and microbial processes, with a particular focus on modern microbialites. My work addresses the microbial influence on the "dolomite problem", incorporating microbial parameters into carbonate formation models, and the role of viruses in biomineralization, bridging insights from both ancient and modern rock records. I actively contribute to multidisciplinary research spanning climatology, the origin and evolution of life, and the formation of microbial reservoirs, aiming to refine our understanding of Earth's biogeochemical processes. Cris have a B.Sc. in Geology from Universidade Rural do Rio de Janeiro, Brazil (1981), M.Sc. in Geochemistry from Universidade Federal Fluminense, Rio de Janeiro, Brazil (1988) and Ph.D. in Natural Sciences Geological Institute, Swiss Federal Institute of Technology (ETH Zurich), Switzerland (1994).

Nilo Siguehiko Matsuda is a Engineer Geologist graduated in 1984 and obtained Sedimentary Basin Analysis MS degree in 1988 from Federal University of Ouro Preto. In 2002, he completed his doctorate (PhD) at Department of Earth & Planetary Science of the University of Tokyo on the subject of "Carbonate Sedimentation Cycle and Origin of Dolomites". He joined Petrobras in 1988 and currently he holds a position as Master Geologist in Exploration focusing on understanding the facies, depositional system and genesis of carbonates reservoir occurred during the Aptian age carbonates of Pre-Salt layers. Additionally, he works in several activities such as studies of carbonate rocks of all ages notably those composed of microbial elements; also, in the characterization of dolomitized reservoirs such as HTD - "High Temperature Dolomite “; the stratigraphy and sedimentology of petroleum systems of Paleozoic basins; supervising field trips courses and consulting on various projects.

Fee:

$730 USD

Attendee Limit:

20

Fee Includes:

Course materials

Transportation

2 nights’ accommodation in a guest house

Field guide

Snacks, Water and Drinks

Venue

Rio de Janeiro, Brasil

Rio de Janeiro, Acre

Brazil

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