Discover Brazil and Explore the Geodiversity and Fossils of the Quarta Colônia UNESCO Global Geopark
- Wayne Munday
- Aug 30
- 5 min read
Updated: 2 days ago
Sip back and discover Brazil and explore the heart of Rio Grande do Sul, Brazil and the Quarta Colônia UNESCO Global Geopark or the Fourth Colonial Geopark. Situated within the vast Paraná Basin, one of the world’s largest intracratonic sedimentary and volcanic basins, the geopark preserves formations from the Early Triassic to the Early Cretaceous, thta tells a story of the recovery of life after the end-Permian mass extinction, the rise of the earliest dinosaurs and the colossal volcanic events that reshaped Gondwana. Fossil-rich beds of the Santa Maria, Sanga do Cabral and Caturrita formations reveal some of the earliest dinosaurs, mammal ancestors and diverse Triassic reptiles, including apex predators like Prestosuchus chiniquensis, agile sauropod ancestors such as Buriolestes schultzi, and small cynodonts like Brasilodon and Brasilitherium that trace the origins of mammals. Later deposits including the Botucatu Sandstone and Serra Geral basalts record ancient deserts and volcanic eruptions that created towering cliffs that helped recharge the Guarani Aquifer one of Earth’s largest freshwater reserves. Beyond its geology and paleontology Quarta Colônia is rich in cultural heritage from Italian-Brazilian vineyards and stone chapels to Indigenous archaeological sites making it a must-visit destination.
The geodiversity of the Quarta Colônia Global Geopark tells a story of over 100 million years of geological history through its landscape of dramatic valleys, cliffs and basalt-capped hills. Its Triassic rock formations are more than 230 million years old and preserve fossils of the earliest dinosaurs, diverse ancient fauna and ancestors of modern mammals including cynodonts.
Massive basalt flows from volcanic eruptions 130 – 125 million years ago mark the breakup of Pangaea and the birth of the Atlantic Ocean. The Quarta Colônia Global Geopark tells a story of the recovery of life after the end of the Permian-Triassic (P-T) mass extinction, known as the "Great Dying", the rise of the dinosaurs and the volcanic events that reshaped the supercontinent of Gondwana formed from the collision and merging of several smaller cratons; the rise of dinosaurs and the volcanic events that reshaped the supercontinent of Gondwana.
The geopark sits within the vast Paraná Basin one of South America’s largest intracratonic sedimentary and volcanic basins spanning 1.4 – 1.6 million km² across Brazil, Argentina, Paraguay and Uruguay. Formed on continental crust and shaped by tectonic processes linked to the breakup of Gondwana and the opening of the South Atlantic.
The stratigraphy of the Paraná Basin reveals six major depositional supersequences beginning with early Paleozoic marine sandstones and limestones, followed by Devonian marine deposits, Paleozoic–Triassic continental sediments and capped by the vast Paraná flood basalts of the Jurassic–Cretaceous part of the Paraná–Etendeka Large Igneous Province. These volcanic eruptions were among the largest in Earth’s history and shaped the basin and contributed to global environmental change.
Reaching a thicknesses of up to 8,000 meters the Paraná Basin rock record includes organic-rich shales such as the Irati Formation which host oil shale deposits as well as coal, limestone, uranium making it a region of significant mineral and energy potential. The Paraná River is one of the world’s largest river systems and overlies the Guarani Aquifer.
Quarta Colônia is especially renowned for its record of some of the world’s earliest dinosaurs. The Santa Maria, Sanga do Cabral and Caturrita formations dating back to the Triassic Period are the cornerstone of the Quarta Colônia Global Geopark's fossil record and marks a pivotal evolutionary turning point.
The Triassic fossils of Quarta Colônia capture a pivotal moment in evolutionary history that saw the dawn of dinosaurs and the origins of mammals. Among the most remarkable finds are Gnathovorax cabreirai, a nearly complete 2.5-meter-long predator; Buriolestes schultzi, a small, swift ancestor of sauropods; and primitive long-necked species such as Bagualosaurus agudoensis and Macrocollum itaquii.
These species indicate the early evolutionary steps towards the giant sauropods that would later dominate the Jurassic Period. These discoveries highlight how dinosaurs transitioned from small omnivores into large more specialist herbivores and carnivores.
Dinosaurs were only one part of this dynamic Triassic Period ecosystem of the Paraná Basin. The land was ruled by the massive apex predator Prestosuchus chiniquensis which grew to over eight meters long while large herds of dicynodonts (Dinodontosaurus) and rhynchosaurs (Hyperodapedon) were widespread.
Equally important were the cynodonts mammal-like reptiles that acted as a transitional group from which modern mammals eventually evolved. These ranged from herbivores like Exaeretodon to predators such as Trucidocynodon including smaller forms of Brasilodon and Brasilitherium lying close to the evolutionary roots of true mammals.
Interestingly, within the Santa Maria Formation is the Pinheiros–Chiniquá Beds that preserve an exceptional fossil record from the Middle to Late Triassic that illustrate the evolutionary radiation of archosaurs before the rise of dinosaurs.
These fossils reveal a diverse ecosystem that included powerful rauisuchians such as Prestosuchus chiniquensis, early dinosauromorphs like Gondwanax and Gamatavus the oldest silesaurids as well as carnivorous gracilisuchids including Parvosuchus aurelioi.
By the Jurassic, shifting dunes and ephemeral lakes of the Guará Formation hosted reptiles and fish adapted to dryer climates. In the Early Cretaceous, vast sand seas formed the Botucatu Sandstone, still visible today in rocky hills and mesas such as Morro Agudo and Monte Grappa which also hold cultural significance as religious pilgrimage sites.
Soon after, enormous eruptions created the Serra Geral Formation a massive basaltic lava province in southern Brazil and Uruguay covering around 917,000 km² and forming part of the Paraná-Etendeka Continental Flood Basalt Province. Dating to the Lower Cretaceous around 120 – 126 million years ago its formation coincided with the opening of the South Atlantic Ocean, driven by a mantle plume, making it a key feature of the Paraná Basin and a classic example of a continental flood basalt province.
The Serra Geral Formation would play a key role in recharging the Guarani Aquifer System mainly through vertical leakage from the overlying fractured basalts where water infiltrated the porous, fractured basalts and percolated downwards.
The Guarani Aquifer sustains ecosystems and communities across much southern South America. Over millions of years rivers carved deep valleys and waterfalls into the basalt and sandstone shaping dramatic landscapes like those seen from the Cerro Comprido and CAPPA overlooks. These valleys would become hubs of human activity incuding the addition of modern hydropower plants such as Dona Francisca and Itaúba.
Beyond geology, Quarta Colônia celebrates a rich cultural mosaic. Italian-Brazilian traditions remain strong in its vineyards, stone chapels, and food festivals, while Indigenous archaeological sites recall much earlier human presence.
