Discover Brazil and Explore the Geodiversity and Fossils of the Caçapava UNESCO Global Geopark
- Wayne Munday
- 1 hour ago
- 3 min read
Sip back and discover Brazil and Explore the Caçapava UNESCO Global Geopark, designated in 2023 in Rio Grande do Sul, Brazil it showcases over half a billion years of Earth’s history. Centered on the Camaquã Basin, a volcano-sedimentary sequence formed during the Ediacaran to Cambrian period over ~600–500 million years ago, the geopark records the tectonic unification of South American Platform to form the Brasiliano orogenic collage and also West Gondwana. The Caçapava UNESCO Global Geopark preserves diverse depositional environments from volcanic flows to delta, lagoon and deep-water sediments as well as some of Earth’s earliest life, including microbially induced sedimentary structures (MISS) of trace fossils like Treptichnus, marking the first burrowing and swimming behaviours of metazoans. Internationally significant geosites such as Guaritas, Serra do Segredo, and Minas do Camaquã show sandstone formations, honeycomb weathering and historic copper mining. Complemented by a rich biodiversity the geopark has many endemic plants, birds, and mammals, as well as Indigenous heritage. The Caçapava Geopark is a unique destination for the visitor to explore.
Designated in 2023 at the heart of the geopark lies the Camaquã Basin a remarkable volcano-sedimentary sequence deposited between the Ediacaran and Cambrian periods over 600 – 500 million years ago. Tectonic rifting created fault-bounded basins across southeastern South America forming a single plate joining the Brasiliano orogenic collage. This collage was a series of tectonic events that had already amalgamated the cratons of Rio de la Plata, São Francisco, Kalahari and Congo forming major mountain belts including the Tocantins, Mantiqueira, Ribeira and Borborema systems during the Neoproterozoic – Cambrian Period the first period of the Paleozoic Era from between ~850 - 490 million years ago forming West Gondwana.
The Camaquã Basin experienced intense volcanism ranging from basaltic to acidic eruptions before the region shifted towards continental tectonic collision. This tectonic upheaval coincided with profound biogeochemical changes including rising ocean oxygen levels, fluctuations in nutrient cycling, and the development of new volcano-plutono-sedimentary successions reflecting environments randing from volcanic landscapes to shallow seas and deep-water systems. These distinct environmental conditions is portrayed in the regional stratigraphy that is divided into five major groups of the Maricá, Bom Jardim, Acampamento Velho, Santa Bárbara and Guaritas each reflecting each depositional setting.
The lower units are dominated by volcanic and volcaniclastic rocks formed through subaerial eruptions and pyroclastic flows, while the overlying Santa Bárbara Group records complex alluvial, delta, and lagoon environments with deep-water turbidite deposits. The younger Guaritas Group is characterised by sandstones, siltstones, and conglomerates that document shifting continental and marine influences.
Interestingly, the Camaquã Basin preserves fine details of ancient life in the form of microbially induced sedimentary structures or sedimentary features created by microbial mats and biofilms interacting with sediments through processes such as biostabilisation, trapping and binding. These sea floor trace fossils in the sediments include wrinkles that show among the earliest ecological innovations of movement among metazoans such as Treptichnus and reveal the growth of microbial mats across both marine and lake environments. At the same time, early reef-builders, predators and sediment-burrowing organisms began to diversify and laying the evolutionary groundwork for the Cambrian Explosion.
The Cambrian Explosion was a rapid evolutionary event during which most major animal phyla first appeared establishing many fundamental body plans seen today. This diversification was driven by factors such as rising oxygen levels, the evolution of predation, and biological innovations including hard skeletons, complex nervous systems and sensory organs. The period saw the emergence of complex marine ecosystems, active movement, burrowing, and intricate predator-prey interactions, creating new ecological niches and laying the foundation for modern animal life.
The Camaquã Basin also preserves paleosols or fossil soils that reveal ancient floodplains and river channels. In combination these sedimentary rocks show how supercontinents assembled and broke apart.
The Caçapava UNESCO Global Geopark features several geosites of international significance. Guaritas is world-renowned for its role in studies of Gondwanan tectonics, showcasing towering sandstone formations that rise like natural fortresses across the landscape. Serra do Segredo captivates visitors with its dramatic mountain scenery and serves as a leading research site for cavernous weathering where wind and water have sculpted intricate honeycomb-like patterns in the rock. Minas do Camaquã, historically a center of copper mining, illustrates the region’s rich mineral wealth and the enduring connection between geology and human industry.
The landscape of sedimentary hills, sandstone cliffs and basalt plateaus of the Caçapava UNESCO Global Geopark supports a diverse ecosystem from endemic cacti and orchids to birds like the white-collared kite and mammals such as ocelots. Human history is equally rich with Indigenous petroglyphs and mining heritage.