Paraguay River 98% of the country's inhabitants. As such the river is considered perhaps the key geographical feature of the country with which it shares its name. Some after flowing through the middle of Paraguay, at the confluence with the Pilcomayo River and passing the Paraguayan capital city, Asunción, the river forms the border with Argentina, flowing generally south-southwesterly for another before it reaches its end, joining with the Paraná River. The Paraguay River is the second major river of the Rio de la Plata Basin, after the Paraná River. The Paraguay's drainage basin, about , covers a vast area that includes
Geology of Paraguay Geology of Paraguay The country of Paraguay lies geologically at the borderzone between several cratons. Due to thick Cenozoic sediment cover and regolith development few outcrops are available in Paraguay. East of Paraguay River that Precambrian and Early Paleozoic crystalline basement crop out mainly in the heights of Caapucú and Apa. The geological processes that have shaped Paraguay's bedrock and sedimentary basins are diverse including rifting, marine sedimentation, metamorphism, eruption of flood basalts and alkaline potassic volcanism. Caapucú High (formerly called "Precámbrico Sur" and "Saliente del Pilar") is the Northwesternmost outcrop of Río de la Plata Craton. The rocks found