The Bam Bam Amphitheaters are large erosional

ravine A ravine is a landform that is narrower than a canyon and is often the product of streambank erosion. Ravines are typically classified as larger in scale than gullies, although smaller than valleys. Ravines may also be called a cleuch, dell, ...

s found in Wonga-Wongue Presidential Reserve in western

Gabon Gabon ( ; ), officially the Gabonese Republic (), is a country on the Atlantic coast of Central Africa, on the equator, bordered by Equatorial Guinea to the northwest, Cameroon to the north, the Republic of the Congo to the east and south, and ...

. Although they are referred to as "

cirque A (; from the Latin word ) is an amphitheatre-like valley formed by Glacier#Erosion, glacial erosion. Alternative names for this landform are corrie (from , meaning a pot or cauldron) and ; ). A cirque may also be a similarly shaped landform a ...

s," they are unrelated to the glacial cirques of high latitudes and mountains. In Gabon, they are east-facing slopes cut into the

Upper Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cret ...

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

s that dip westward beneath the Atlantic Ocean. Because the sandstones are higher and drier than the surrounding coastal plain, they are covered with grasslands rather than the prevailing

tropical rain forest Tropical rainforests are dense and warm rainforests with high rainfall typically found between 10° north and south of the Equator. They are a subset of the tropical forest biome that occurs roughly within the 28° latitudes (in the torrid zo ...

. As the sandstones are locally intensely colored, and because the steep slopes tend to be barren, the "cirques" locally appear to be "

badlands Badlands are a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded."Badlands" in '' Chambers's Encyclopædia''. London: George Newnes, 1961, Vol. 2, p. 47. They are characterized by steep slopes, ...

" similar to those of the American West.Horner, R. H., 1985, The Gabon Basin: its regional setting with respect to onshore basement tectonic elements as interpreted from side-looking airborne radar imagery: Remote Sensing for Exploration Geology, 4th Thematic Conference, Proceedings, Environmental Research Institute of Michigan, p. 31-47.

References

Landforms of Gabon Ravines {{Gabon-geo-stub