The Santos Basin is a mostly offshore sedimentary basin across the Tropic of Capricorn, bordering from north to south the Brazilian states of Rio de Janeiro, Sáo Paulo, Paraná and Santa Catarina.
The basin covers an area of approximately 352,000 square kilometres (136,000 sq mi), and is bounded in the north by the Cabo Frio High, separating the basin from the Campos Basin and the Florianópolis High and Fracture Zone, separating the Santos Basin from the Pelotas Basin.

Along the Brazilian coast, the basin is bounded by the Serra do Mar and stretches from Cabo Frio in the northeast to Florianópolis in the southwest.
The city of Rio de Janeiro is located at the coastal edge of the Santos Basin in the northern portion, Santos, Guarujá and the islands of Ilhabela in the central area and Itajaí and Balneário Camboriú in the south of the basin.
Within the basin, several highs are located.
The Outer High, in the distal part of the Santos Basin, is the most prominent and extensive intra-basinal high with an approximate area of 12,000 square kilometres (4,600 sq mi).
The Outer High is likely a segmented series of rift fault-block shoulders which were uplifted and eroded during the Late Barremian.

The climate of the onshore stretch of the basin ranges from tropical savanna climate (Aw), tropical monsoon climate (Am) and tropical rainforest climate (Af) to a humid subtropical climate (Cfa).
The onshore portion of the Santos Basin is in the Serra do Mar coastal forests ecoregion of the Atlantic Forest biome.
On the islands of the Superagüi National Park in the Santos Basin, the endemic critically endangered Superagüi lion tamarin (Leontopithecus caissara) has its restricted habitat.
The Santos Basin is a mostly offshore sedimentary basin across the Tropic of Capricorn, bordering from north to south the Brazilian states of Rio de Janeiro, Sáo Paulo, Paraná and Santa Catarina. The basin covers an area of approximately 352,000 square kilometres (136,000 sq mi), and is bounded in the north by the Cabo Frio High, separating the basin from the Campos Basin and the Florianópolis High and Fracture Zone, separating the Santos Basin from the Pelotas Basin.
Along the Brazilian coast, the basin is bounded by the Serra do Mar and stretches from Cabo Frio in the northeast to Florianópolis in the southwest. The city of Rio de Janeiro is located at the coastal edge of the Santos Basin in the northern portion, Santos, Guarujá and the islands of Ilhabela in the central area and Itajaí and Balneário Camboriú in the south of the basin. Within the basin, several highs are located. The Outer High, in the distal part of the Santos Basin, is the most prominent and extensive intra-basinal high with an approximate area of 12,000 square kilometres (4,600 sq mi). The Outer High is likely a segmented series of rift fault-block shoulders which were uplifted and eroded during the Late Barremian.
The climate of the onshore stretch of the basin ranges from tropical savanna climate (Aw), tropical monsoon climate (Am) and tropical rainforest climate (Af) to a humid subtropical climate (Cfa). The onshore portion of the Santos Basin is in the Serra do Mar coastal forests ecoregion of the Atlantic Forest biome. On the islands of the Superagüi National Park in the Santos Basin, the endemic critically endangered Superagüi lion tamarin (Leontopithecus caissara) has its restricted habitat.
Santos Basin