Cerro Autana as other table-top mountains in the region is the remains of a large sandstone plateau that once covered the granite basement complex between the north border of the Amazon Basin and the Orinoco, between the Atlantic coast and the Rio Negro. The table-mountain topography is formed as water percolates along joints and bedding planes, the siliceous cement dissolves, quartzite disaggregates and large blocks collapse which accumulate in the foot of the scarps. The percolating water forms large and intricate cave systems, which frequently emerge in the scarp zone as high waterfalls.