April 27, 2026

Geology and Mineral Resources – Papua New Guinea

Introduction

Figure 1 – Papua New Guinea
Credit: Creative Commons Attribution-Share Alike 3.0 Licence

The Independent State of Papua New Guinea (PNG) is a country of 10,185,363 people (2024 census) comprising the eastern half of the island of New Guinea in Oceania. PNG has an area of 462,840 square kilometres and includes a large mainland with hundreds of Melanesian offshore islands in. PNG has a land border with the Indonesian territory of Western New Guinea. The country has maritime borders with Australia to the south and the Solomon Islands to the east.

PNG is a relatively poor country with a per capita GDP (PPP) of $3,760 and a medium Human Development Index of 0.576.The country’s population is largely rural and the economy is mostly subsistence agriculturewith most of the capital investment concentrated in natural resources such as mining and petroleum (see below).

In 2024, the top exports of PNG were natural gas, gold, copper ore, crude petroleum, and palm oil. The top destinations were China, Japan, Australia, South Korea, and Taiwan. In 2024, the top imports of PNG were refined petroleum, rice, delivery trucks, excavation machinery, and motor vehicles including parts and accessories. The top origins were Australia, China, Singapore, Malaysia, and Japan.

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

Geology

Figure 2 – Tectonic Framework of PNG
Credit: Eric Gaba, Creative Commons Attribution-Share Alike 2.5 Generic license

Tectonically, the island of New Guinea sits on the northern edge of the Australian Plate where it forms a convergent boundary with the Pacific Plate and a host of smaller microplates including:

• The Woodlark microplate (WL), which is bounded to the north by the New Britain Trench and the South Solomon Trench, to the southeast by the active Woodlark seafloor spreading center, and to the southwest by a convergent boundary with the Australian Plate.

• The South and North Bismarck microplates: the Bismarck Sea is a back-arc basin with respect to the New Britain arc and is divided into the North Bismarck (NBS) and South Bismarck (SBS) microplates.

• The Manus microplate (MN) squeezed between the South and North Bismarck microplates

• The Caroline microplate in north-central New Guinea and extending under the Pacific Ocean.

• The Solomon Sea microplate (SS), between the Woodlark plate, the South Bismark Plate and the Pacific Plate.

• The Maoke microplate (MO), to the west of the Woodlark plate; west of the Maoke plate is the Bird's Head microplate (BH).

It’s all very complex and reflects a complex tectonic history. A very good paper that describes the tectonic framework of New Guinea is: “Suzanne L. Baldwin, Paul G. Fitzgerald, Laura E. Webb. 2012. Tectonics of the New Guinea Region. Annual Review Earth and Planetary Sciences. 40:495-520. https://doi.org/10.1146/annurev-earth-040809-152540”, which you can also download from here.

Figure 3 – Geology of New Guinea
Credit: Figure 1 in Misztela et al, 2022

Figure 3, above,  summarizes the geology of New Guinea

• The oldest rocks on the island are Paleozoic and Proterozoic basement complexes and sediments.

• Next in age are the Paleozoic aged deposits in the Papuan Fold Belt that were folded during the Mesozoic Era.

• The Papuan Basin is made up sediments ranging in age from Paleozoic to Cenozoic in age.

• The Cretaceous and younger deposits of the Aure Fold Belt were deformed from the Miocene to the present.

• In places, the Paleozoic basement is overlain by Mesozoic aged sediments.

• Tectonic activity has deformed some of the Mesozoic and Cenozoic into metamorphic rocks.

• Ophiolites are found in the Papuan Ultramafic Belt.

• Volcanic rocks – ocean floor basalts, volcanic arc deposits, and diorite intrusions – range in age from Cretaceous to Neogene.

• Various Miocene aged sediments, especially limestone.

This is only scratches the surface of the geological complexity of New Guinea. A good place to start further reading is: Davies H.L., 2012, The geology of New Guinea - the cordilleran margin of the Australian continent, Episodes 2012;35:87-102, https://doi.org/10.18814/epiiugs/2012/v35i1/008.

Paleontology

With its complex geology, you might expect there to be some fossils in PNG. A few have been found, many are so-called megafauna from the Quaternary. Here are some examples:

Protemnodon tumbuna

Figure 4 - Protemnodon tumbuna reconstruction
Credit: Apokryltaros at English Wikipedia, 
Creative Commons Attribution 3.0 Unported license

A giant kangaroo, Protemnodon tumbuna was one of many species of the genus, Protemnodonthat lived during the Quaternary Period in Australia and New Guinea. T. F. Flannery, M. J. Mountain, and K. P. Aplin published their discovery of Protemnodon tumbuna in 1983, from fossils found in the Nombe rock shelter in PNG. A new species of Protemnodon from was New Guinea was described in 2022.

Thylacinus cynocephalus

Figure 5 - Thylacinus cynocephalus reconstruction
Credit: Henry Constantine Richter (1821–1902), public domain

The thylacine (Thylacinus cynocephalus), also called the Tasmanian tiger or Tasmanian wolf, lived throughout Australia and New Guinea during the Pleistocene and persisted in Australia until the last specimen died in a zoo in Tasmania. A predator, examples of fossil thylacines were found in the Nombe rock shelter in 1990. Some people claim that it still exists in PNG.

Hulitherium tomasetti

Figure 4 - Hulitherium tomasetti Restoration
Credit: Peter Schouten
Creative Commons Attribution 4.0 International license

Hulitherium tomasetti was a large zygomaturine marsupial that lived in New Guinea during the Pleistocene. First found by a Roman Catholic priest, Fr. Berard Tomasetti, the fossils of H. tomasetti were first described scientifically in 1986 by T. F. Flannery and M. Planefrom fossils found in swamp sediments in Pureni, Southern Highlands Province. H. tomasetti was the largest mammal yet known from the Quaternary of New Guinea.

Mineral Resources

Figure 7 – Gold, Mount Kare, Porgera, Auagum Range, Western Highlands, Papua New Guinea
Credit: Daderot, Creative Commons CC0 1.0 Universal Public Domain Dedication

According to the latest USGS Minerals Yearbook for Papua New Guinea, the mineral industry of PNG includes the production of metallic minerals, industrial minerals, and fuel minerals. The latest statisitcs on production from the USGS are here.

Industrial and Metallic Minerals

• The only industrial mineral production in PNG is a cement plant in Lae, Morobe Province.

• Chromium, cobalt, and nickel are mined at the Ramu Mine in Madang Province, Ramu Nickel & Cobalt Management (MCC) Co., Ltd. website here (in Chinese).

• Copper, gold and silver are mined at the Kainantu Mine in the Eastern Highlands and at the Ok Tedi open pit mine in the Western Province.

• Gold and copper are mined at the Sinivit open pit mine in East New Britain Province.

• Gold and silver are mined at the Hidden Valley open pit mine in Morobe Province; and at the Porgera open pit mine in Enga Province.

• Gold alone is mined at the Tolukuma Hill open pit mine in Central Province; at the Lihir open pit in Niolam Island, New Ireland Province; and at the Simberi Island open pit mine in New Ireland Province.

Petroleum and Natural Gas

Figure 8 - Map of Oil And Gas Projects and Pipelines in Papua New Guinea
Credit: Figure 9 in Mosusu et al, 2023, CC BY 4.0

PNG is developing its oil and gas resources, and there is great potential for more development. Major fields include the Agogo Field, Gobe Field, Kutubu Field, and the Moran Field. PNG is also developing a liquid natural gas export facility near Port Moresby, National Capital Region.

Summary

Figure 9 – Fishing in Vunapope, East New Britain, PNG
Credit: Tarotastic, Creative Commons Attribution 2.0 Generic license

PNG has a great potential for further mineral and oil / gas development. Some people hope that it will significantly increase the standard of living for the people of PNG, especially oil and gas development. Others question if such development is desirable. However, for geoscientists, there are lots of potential opportunity.

Politically, PNG has had its problems, perhaps not surprising for a country with 839 indigenous languages and at least that many ethnic groups. The Australian government advises travellers to PNG to exercise a high degree of caution due to high levels of crime, tribal violence and civil unrest.

Pay your money and take your chances.

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.