Topography of the PPSRNP varies from flat terrain to rolling hinterlands, from hills to mountain peaks. The landscape is split at the center by a limestone or karst formation known as the St. Paul limestone. The main peaks are Mt. St. Paul (1,028m), Cleopatra’s Needle (1,500m) at the east and Mt. Bloomfield (870m) on the west. Park is underlain by rock formations consisting of recent alluvium, sandstone and shale. The recent alluvium is made up of transported clay, silt and pebbles.
The limestone or karst formation is estimated to be 20 million years old, is 11 km long, average 4 km in width, and covers an area of around 35 sq. /km, The PPUR host a unusually high number of 11 minerals including the rare mineral “ Serrabrancaite” or manganese phosphate.