Raymond’s Geology Blog
May 4, 2026

Geology and Mineral Resources – Paraguay

Introduction

Figure 1 – Paraguay
Credit: Mapsland, Creative Commons Attribution-Share Alike 3.0 Licence

The Republic of Paraguay is a landlocked country of 7,439,863 people in South America. The country has an area of 406,752 square kilometres and borders on Bolivia to the northwest and north, Brazil to the northeast and east, and Argentina to the southeast, south, and west. Oceangoing trade can reach Paraguay via the Paraná–Paraguay Waterway which leads to the Rio de la Plata and the Atlantic Ocean.

Paraguay is a moderately wealthy country with a per capita GDP (PPP) of $23,350 and a high Human Development Index of 0.756. Paraguay’s economy is based upon agricultural production, export of agricultural commodities, and general trade, especially importing goods from China for re-export to nearby Brazil. Another important export is electrical power to Brazil from the Itaipu Hydroelectric Project. Much of the trade that goes on within Paraguay is in the informal economy, and for a long time Paraguay was renowned for illicit trade in drugs and weapons. In 2024, the top exports of Paraguay were soybeans, electricity, beef (both frozen and fresh), and soybean meal. The top destinations for exports were Brazil, Argentina, Chile, the United States, and Taiwan (Chinese Taipei). In 2024, the top imports of Paraguay were refined petroleum, telephones, cars, pesticides, and computers. The top origins for imports were China, Brazil, United States, Argentina, and Chile.

For more details on the country, check out the Wikipedia and Grokipedia articles on the country.

Geology

Figure 2 – West Gondwana during the Triassic Period
Credit: Woudloper, Creative Commons Attribution-Share Alike
3.0 Unported, 2.5 Generic, 2.0 Generic and 1.0 Generic license

Paraguay sits on the South American tectonic plate. The country also overlies parts of Río del la Plata Craton, Río Tebicuary Craton, and Río Apa Craton. Overall, the geology of Paraguay consists of:

Figure 3 – Geological Map of Paraguay
Credit: Figure 6 in M. A. G. Villalba, 2021, CC BY 4.0

The oldest deposits in Paraguay are the Mesoproterozoic aged rocks of the Río Apa Craton, the Río Tebicuary Craton, and the Itapucumí Group. The outcrops of the Río Tebicuary Craton in southern Paraguay are sometimes considered the northernmost extension of the Río de la Plata Craton and are called the Caapucú High. The rocks of the Caapucú High are a suite consisting of porphyritic granite, orthogneiss, paragneiss, amphibolite, migmatite, talc schist, and rhyolite dykes.

The outcrops of the Río Apa Craton in north-central Paraguay are also called the Apa High. The deposits of the Apa High include Proterozoic aged granite, metasediment, mafic gneiss and intrusions of pegmatitic granite.

Overlying the Apa High deposits are rocks of the Neoproterozoic to Silurian aged Itapucumí Group. The Itapucumí Group comprises, from base to top, siliciclastic rocks (Vallemi Formation), succeeded by limestones and dolostones (Camba Jhopo and Tagatiya Guazu formations), and which in turn are overlain by marls and mudstones (Cerro Curuzu Formation). Overall, the group represents three depositional sequences deposited in a large rimmed carbonate platform. The Itapucumí Group includes Ediacaran aged shelly fossils and treptichnids

Next in age are the Neoproterozoic to Cambrian, Ordovician, and Silurian aged deposits of the Caapucú Suite which overly the Río Tebicuary Craton and extend into Brazil. These are a mix of sedimentary and volcanic rock.

In central and western Paraguay is the Phanerozoic aged Chaco Basin. The Chaco Basin was formed in a sequence of sedimentary deposition that began in the Neoproterozoic and continued into the Quaternary. The deposits transition from marine to continental sediments and include evaporites in the final phases.

In eastern Paraguay, much of the Phanerozoic geology is part of the Paraná Basin. The intracratonic Paraná Basin consists of sedimentary deposits spanning in age from the Paleozoic to the Cenozoic.

Overlying the sedimentary rocks of the Parana Basin are extensive basaltic flows of the Paraná Large Igneous Province (PLIP), Jurassic-Cretaceous age. The PLIP were deposited during the opening of the South Atlantic Ocean. Also called the Paraná and Etendeka Traps, the rocks of the PLIP consist of tholeiitic basalt and a variety of silicic volcanic deposits such as ignimbrite, quartz latite, and pyroclastic deposits.

Paleontology

Fossils found in Paraguay range in age from the Ediacaran to the Pleistocene, quite a range in time. Lets look at a few of them.

Corumbella werneri

Figure 4 - Corumbella werneri
Credit: Abner Santos, Creative Commons Attribution 4.0 International license

Corumbella werneriwas a sessile animal that lived at the end of the Neoproterozoic during the Ediacaran Period. It’s fossils have been found as burrows in the mud that later became rock. In Paraguay, the Corumbella werneri was found in the Tagatiya Guazu Formationof the Itapucumí Group.

Arenorthis paranaensis

Figure 5 – Examples of Arenorthis including Arenorthis paranaensis
Credit: Figure 5 in Bendetto et al, 2013

Arenorthis paranaensiswas a brachiopod that lived during the Hirnantianstage of the Ordovician Period in what is now the Parana Basin of Paraguay. Arenorthis paranaensiswas first identified in the Eusebio Ayala Formation and published in Bendetto et al, 2013.

Stegomastodon sp.

Figure 6 – Stegomastodon sp. Skeleton
Credit: WolfmanSF, public domain

Stegomastodon sp. was a gomphothere elephant that lived throughout the Americas during the Pliocene and Pleistocene. Bones of Stegomastodon sp. were found in 2008 in Colonia Paratodo in the Paraguayan Chaco region.

Mineral Resources

Figure 7 – Strontiochevkinite specimen from Paraguay
Credit: David Hospital, Creative Commons Attribution-Share Alike 4.0 International licence

According to the USGS Minerals Yearbook for Paraguay, mineral production in Paraguay is pretty much limited to industrial minerals - cement and lime production for construction – and local refining of iron and steel.

The Uranium Energy Corp has a project to mine and refine titanium in the Alto Parana region, but there are concerns that the project may not go forward.

For oil and gas exploration, there appears to be good potential in the Chaco and Parana basins, but the petroleum industry of the country remains underdeveloped.

Summary

Figure 8 - Sunset in the Mbatoví Eco Reserve Paraguay
Credit: Eco reserva Mbatoví, Creative Commons Attribution-Share Alike 4.0 International licence

Paraguay has often been a destination for people to escape from issues they may be having in their own country. Some have principled reasons to get away, such as the Mennonites who just wanted to be left alone. If you look at the map of Colonia Paratodo, you will notice some German sounding place names. This is because Mennonites, many from Manitoba, settled the area in the 20th Century.

Other people have fled to Paraguay to escape criminal prosecution in their own country. With its weak public institutions some people have been able to buy safe haven in Paraguay.

For geoscientists, while there appears to be great potential for mineral development in Paraguay, especially in the Chaco and Parana basins. However, those weak public institutions and endemic corruption may make it difficult to operate in the country. So it might be a while before exploration geologists can send Postcards from Paraguay.

Standard Caveat

J. Robert Oppenheimer on freedom and scientific inquiry

The purpose of my weblog postings is to spark people's curiosity in geology. Don't entirely believe me until you've done your own research and checked the evidence. If I have sparked your curiosity in the subject of this posting, follow up with some of the links provided here. If you want to, go out into the field and examine some rocks on your own with the help of a good field guide. Follow the evidence and make up your own mind.

In science, the only authority is the evidence.