The Atlantic Forest in South Brazil covers 1.000 meter thick, heavily eroded, mesozoic lava layers, the so-called Paraná Flood Basalts. They are evidence of the most voluminous magmatic event known on Earth, during Pangea break-up.
Climate is subtropical, getting constantly cooler with increasing latitude and vegetation becomes less diverse. The presence of Paraná pine trees (Araucária) is common.