Serra da Cangalha
Key facts
- Country
- Brazil
- Diameter
- 13 km
- Age
- less than about 300 million years
- Location
- 8.08° S, 46.87° W
A striking ring of hills about 13 km across in the savanna of Tocantins, Brazil, with a high inner ring around a central basin. It is clear on satellite images.
Serra da Cangalha is one of the most spectacular impact structures in South America, a series of rings of hills about 13 km across in the state of Tocantins, north-central Brazil.
What it hit. The impactor struck the sedimentary rocks of the Parnaíba Basin, mainly sandstones, siltstones and shales of Palaeozoic age. The rebound of the crater floor raised a central uplift, which erosion has carved into a high ring of hills about 3 km across, enclosing a central hollow. Around it, an outer ring of ridges marks the collapsed rim of the crater.
Proof of impact. The structure's striking shape was noticed on satellite images in the 1970s. Field studies found shatter cones, cone-shaped fractures produced by shock, and quartz grains with planar deformation features, the microscopic fingerprint of an impact.
Age. The youngest rocks affected are Permian, about 300 million years old, so the impact happened after that. Its exact age is unknown.
Why it matters. Serra da Cangalha's well-exposed central ring makes it an excellent place to study how central uplifts form and erode. It is often compared with similar ringed craters on Mars. The impactor is unknown.
Visiting. The structure is remote, reached by dirt roads. Ask permission before entering private farmland.
Did you know?
Serra da Cangalha's rings of hills are clearly visible from space.
Its central uplift has eroded into a ring of hills about 3 km across.
It is often compared with ringed craters on Mars.