Geology of Paraguay Basin. These tholeiites were erupted in the Early Cretaceous in association with the initial opening of the South Atlantic. The Cretaceous volcanism did also created minor outcrops of potassic alkaline volcanics in a graben structure developed between Asunción and Villarrica and in Amambay Department. Cretaceous volcanism did also left small units of sodic alkaline rocks in Misiones Department in southern 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
History of Paraguay (to 1811) those of the Jesuits. Tensions between the natives and the Europeans grew steadily during the last years of the 18th century. Almost no archaeological research has been done in Paraguay, and the pre-Columbian history of the country is amazingly documented. What is certain is that the eastern part of the country was occupied by Guaraní Indians for at least 2 years before the Spanish conquest. Evidence indicates that those indigenous inhabitants developed a fairly sophisticated level of political autonomy, with quasi-sedentary, multivillage chiefdoms. The recorded history of Paraguay began indirectly in 1516 with the failed expedition of Juan Díaz de