FIELD TRIP
Alluvial systems of the Continental Rift of Southeastern Brazil: Paleogene and Neogene tectonoclimatic records
Leaders: Professor André Pires Negrão, PhD (IGc-USP), and collaborators.
The Continental Rift of Southeastern Brazil (CRSB) field trip will examine, through outcrop analysis, the alluvial processes and products associated with the rift and post-rift phases of the CRSB, within the broader context of the Cenozoic tectonic and climatic evolution of southeastern Brazil. Secondary topics will include siliciclastic reservoir analogues, stratigraphic and structural traps, intraplate seismicity, and hydrogeology. These topics will be discussed within the Central Segment of the CRSB, with the selected outcrops distributed across the Taubaté, Resende, and Volta Redonda basins.
For participants unfamiliar with the region, it is worth noting that the CRSB contains some of the most remarkable topographic and magmatic features in the South Atlantic region. Its evolution is closely linked to the adjacent offshore domain, which encompasses the Santos and Campos basins, Brazil’s most prolific oil- and gas-producing basins. The geomorphological framework of the onshore region comprises the Serra da Mantiqueira and Serra do Mar mountain ranges, forming a complex system of tectonic valleys and fluvial-coastal lowlands bounded by ENE–WSW-trending ranges. Elevations frequently reach 2,000 m along escarpments located near the coastline. This topography records successive uplift and volcanic events, particularly those that occurred after the breakup of Gondwana.
Key Aspects of Alluvial Sedimentation in the CRSB
Paleogene alluvial sedimentation in the CRSB is highly distinctive, comprising thick successions of braided-fluvial and alluvial-fan deposits composed of arkoses and subarkoses, smectite-rich mudstones, and calcretes. These deposits differ markedly from any Quaternary or modern alluvial record in Brazil. However, Paleogene sedimentary successions from different areas of southeastern Brazil, including regions outside the CRSB, display strong textural and compositional similarities, suggesting significant regional and global climatic controls.
From the Miocene onward, post-rift sedimentation displays depositional patterns—predominantly associated with meandering fluvial systems—and textural and compositional characteristics that are considerably more similar to those found in modern environments of southeastern Brazil.
Logistics and Recommendations
The field trip will depart from and return to the University of São Paulo Institute of Geosciences (IGc-USP), where the event will be held. All transportation will be provided by a van and a support vehicle.
Activities will take place within the Central Segment of the CRSB, which encompasses the Paraíba do Sul River valley in the states of São Paulo and Rio de Janeiro. Taubaté (SP) and Resende (RJ) will serve as the main reference cities and overnight stops. The primary travel route will be the Presidente Dutra Highway (BR-116), which connects the cities of Rio de Janeiro and São Paulo and runs longitudinally through the entire Central Segment of the CRSB. Most of the outcrops to be visited occur in artificial roadcuts along this highway and along state and municipal roads in both urban and rural areas.
The Price Includes
Bus transportation throughout the trip.
The Price Does Not Include
Airfare;
Trip cancellation insurance;
Accommodation with breakfast (estimated cost in BRL, to be confirmed);
Meals—one lunch, one snack, and one dinner per day (estimated daily cost in BRL, to be confirmed).
Duration: 4 days (3 nights)
Maximum number of participants: 20
Cost: Approx. EUR 210 (may vary by EUR 35, up or down)
