October 27, 2025
News and notes
A path in the Bush, Fall 2025
This week, before going on to discuss the geology and mineral resources of Mauritius, we will first look at some news items I thought were interesting. If you enjoy my blogs, bookmark the site and check Monday mornings rather than relying on social media postings which can get lost in the shuffle.
Comments
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Geopolitics
What could go wrong? Chinese Nationals Arrested In Georgia For Attempting To Buy Black Market Uranium.
Trump strikes deals on trade, critical minerals in Southeast Asia.
The big winners from the Australia-US critical minerals deal.
Ukraine Strikes Russia’s Fourth-Largest Refinery, Disrupting 80,000 bpd.
Pipeline to Egypt: Energean Signs Gas Transmission Deal for Israel’s New Pipeline.
With new export controls on critical minerals, supply concentration risks become reality.
Supply chain independence: China Moves to Break Free from Its Last U.S. Dependencies with a €1.4 Billion High-Purity Quartz Discovery.
Research and News
Software and petrology: Constraining the Impact of Post-Entrapment Crystallization Correction Algorithms on Melt Inclusion Compositions and Petrological Interpretations With MagmaPEC.
U-Pb Zircon Ages of the Knight Peak Outflow Sheet and Lava Sequence, Mogollon-Datil Volcanic Field, New Mexico, USA: Implications for Magmatism and Extension in the Southeastern Basin and Range Province in the October 2025 edition of New Mexico Geology.
Geophysics: Radial Anisotropy Beneath the Continental U.S. From Surface Wave Phase Velocities.
Low-Temperature (100°C–300°C) Magnetite Production in Variably Serpentinized Lherzolites.
Adventurers and hikers can now download the new USGS topographic maps for free.
The magnetosphere is changing: Core field changes from eleven years of Swarm satellite observations; Science Alert summary here.
Planetary Geology
Plate Tectonics
Geophysics and plate geometry: A Magnetotelluric Study of Mantle Heterogeneities Beneath the Northeastern United States.
Mapping a subduction zone: Seismic Imaging of the Transition From Normal to Flat Subduction in Southern Peru by Full Waveform Inversion of Teleseismic Waves.
Wilson cycle: A Recipe for Exotic Continental Fragment Formation: Key Constraints From Numerical Rift Models.
Symmetry versus asymmetry of rifted margins: The role of mechanical anisotropy.
A 3D Velocity Model for the European Alps: New Insights Into the Crustal Structure.
Morphometric Evidence for Cenozoic Intraplate Reactivation in NW Uruguay.
Paleontology
Central Asian radiation of modern large-mammal faunas in Miocene.
Geochemistry and paleontology: Species-Specific Offsets in Manganese Incorporation in Hyaline Foraminiferal Calcite Across a Gradient of Seawater [Mn].
Middle Miocene (Badenian) fishes from the north-west of the Fore-Carpathian Basin.
Dinosaurs in New Mexico thrived until the very end, study shows; referenced papers here and here.
An Early Cretaceous Record of the Mawsoniid Coelacanth Axelrodichthys from Niger.
Small, enigmatic alligatoroid from the Middle Eocene Clarno Formation, John Day Fossil Beds, Oregon.
Ancient ‘salt mountains’ in southern Australia once created refuges for early life.
A global coral phylogeny reveals resilience and vulnerability through deep time.
A new insect boring in fossil wood from the Iranian Upper Cretaceous.
Ore Deposit and Petroleum Geology
Mining and Energy
Ontario Investing $1 Billion to Build Small Modular Reactors at Darlington.
Annual report: Australia’s Energy Commodity Resources 2025.
Ooh shiny: Rare half-pink rough diamond with 'astounding' weight of 37.4 carats discovered in Botswana.
Australia's first fluorite mine faces 'deep opposition' from Kimberley traditional owners.
Access to export markets: How One Pipeline Turned Canada Into a Global Energy Power.
Canada Nears a Historic Clean-Energy Breakthrough: A Nuclear Reactor That Consumes Its Own Waste.
Energy: Canadian Province Moves to Limit AI Power Use, Ban Crypto Mining.
Falling prices: Russia’s Coal Collapse Marks The End Of Fossil Fuels’ Post-War Illusion.
Australia: “Earth’s biggest iron deposit” : 55-billion-ton find puts remote region in the global spotlight.
Environmental Geology and Hydrogeology
Coastal Hydrogeology in an Age of Rising Seas; abstracts from the GSA 2025 conference.
Groundwater seepage: Scientists discover hidden underground oases beneath the shrinking Great Salt Lake.
Leaked tritium reveals the source of 137Cs from the Fukushima Daiichi Nuclear Power Plant to the ocean; Phys.org summary here.
Glaciers and Climate Change
Tidewater cycle drives alpine glacial sediment plume geochemistry.
Ancient climate change: Late Miocene Arctic warmth and terrestrial climate recorded by North Greenland speleothems.
Volcanoes, Earthquakes and Geohazards
Volcanoes
The United States Geological Survey (USGS) Volcano Observatories are not reporting because of the US government shutdown; there is, however, the Cascades Volcano Observatory Weekly Update.
Volcano-Tectonic Crisis of Mayotte (2018–2022): A Deformation Model for Geodetic Applications.
Earthquakes
Differentiating Frictionally Locked Asperities From Kinematically Coupled Zones.
M 5.9: Costa Rica Shaken by a Quake with No Injuries Reported; USGS summary here.
Rupture of solidified ancient magma that impeded preceding swarm migrations led to the 2024 Noto earthquake; Japan Times summary here.
Free Geology Books and Other Stuff
Free geology books can be downloaded from these sites:
OreZone Readers and Experts Telegram Channel; the Ore Zone channel also shows employment opportunities for geologists.
The Groundwater Projecthas many groundwater geology books for free download; also they now have a Free Online Learning Module: Pumping Test Analysis.
Free Groundwater Modeling Course – HydroGeoCenter.
From Western Australia: Carbonatite, lamprophyre and host rocks in the northern Aileron Province.
Two volumes of Geology of Indonesia now can be accessed for FREE/GRATIS. The books can be accessed from: vol 1 https://lnkd.in/eH6Gcka4; vol 2 https://lnkd.in/egTYmpjk.
Brett Davis’ book on veins in a deforming rock mass: “The Veining Bible”; also at this site.
From the Mineralogical Society of America: Handbook of Mineralogy.
Upcoming Events
2025 Kentucky Geological Survey Geoscience Open House; October 28, 2025.
Free online course: November 4 – 5, Principles of U-Pb geochronology, Instituto de Geología, UNAM; registration deadline November 3.
November 3 – 4, 2025 Central Canada Mineral Exploration Convention 2025 Victoria Inn Hotel & Convention Centre, 1808 Wellington Avenue, Winnipeg, Manitoba R3H 0G3, Canada.
5th International Professional Geology Conference (IPGC), November 5 to 7, 2025, Zaragoza, Spain.
Saskatchewan Geological Open House, December 1 to 3, 2025, Delta Bessborough Hotel, Saskatoon; Registration for the 2025 Conference now open.
GAC-MAC 2026 St. John's NL, St. John's Convention Center, May 25-28, 2026.
Society of Petroleum Engineers Distinguished Lecturer Schedule.
The Geological Society: Events & Courses.
International Union of Geological Sciences calendar of geoscience events.
“Geology Hour” Online, evenings on the 3rd Monday of the Month from the Geological Society of the Oregon Country.
October 27, 2025
Geology and Mineral Resources – Mauritius
Introduction
Figure 1a –
Mauritius
Credit:
CIA
World Factbook, public
domain
Figure 1b – Location
of Mauritius
Credit:
CIA
World Factbook, public
domain
A former British and French colony, the Republic of Mauritius is an island country of 1,310,504 people in the Indian Ocean, east of Madagascar. The country has an total area of 2,040 square kilometres and includes the main island of Mauritius together with Agalega, Cargados Carajos Shoals (Saint Brandon), and Rodrigues Island. Mauritius, together with its smaller territories, is part of a larger geographic entity, the Mascarene Islands, which also includes the French Department of Réunion.
.svg)
Figure 2 – Chagos
Archipelago and Mauritius
Credit:
Yashveer
Poonit, WikiForMen,
Creative
Commons Attribution-Share
Alike 3.0 Unported license
Mauritius also claims the Chagos Archipelago and has been in a territorial dispute with the United Kingdom over the Archipelago since 1965. The Chagos Archipelago includes the strategic naval base of Diego Garcia and, until very recently, the U.K. has been loathe to give up ownership of the islands. However, as of October 20, 2025, the U.K. government has ceded the Chagos Archipelago to the Republic of Mauritius.
Mauritius enjoys a moderately high standard of living with a per capita GDP (PPP) of $33,954 and a very high Human Development Index of 0.806. Mauritius has a diversified economy, based on tourism, textiles, sugar, and financial services. For more details on the country, check out the CIA World Factbook on Mauritius as well as the Wikipedia article.
Geology
Figure 3 – Track of the Réunion Hotspot Chain, Credit: Figure 1 in Torsvik et al, 2013
Mauritius is a volcanic island that owes it origin to the Réunion Hotspot and the tectonic forces that drove the Indian subcontinent northeastward from Gondwana towards the Eurasian Plate during the Late Cretaceous Epoch and into the Eocene Epoch. These same tectonic movements are responsible for the volcanic rocks underlying the Chagos Archipeligo, the Maldive Islands and the Deccan Traps in India. Overall, the volcanic rocks originating in the Réunion Hotspot form part of the Deccan Large Igneous Province.
Figure 4 – Geology of
Mauritius
Credit:
Figure 1 in Paul,
White, & Blichert-Toft, 2005
Recent studies divide the volcanic rocks of Mauritius into three categories:
The Older Series, dated at 8.9 million years ago (Mya) to 4.7 Mya.
An Intermediate Series, dated at 3.5 to 1.9 Mya and,
A Younger Series, dated at 113 ± 7 thousand years ago (Kya) to 14 ± 3 Kya.
The Older Series volcanic rocks in Mauritius were extruded in two phases: a shield-building phase consisting of picrobasalt flows and agglomerate; and a second stage composed of feldsparphyric basalt, hawaiite, mugearite, and trachytic intrusive rocks. The Intermediate Series consists of olivine-phyric alkali basalt, basanite, and nephelinite while the Younger Series consists predominantly of potassium-poor alkaline olivine basalts with subordinate basanite.
Mineral Resources
Figure 5 – Salt
Production, Tamarin,
Mauritius
Credit:
Arne Müseler, Creative
Commons Attribution-Share
Alike 3.0 Germany license
The mineral industry of Mauritius is limited to locally produced building materials – crushed stone, sand and gravel – and sea salt. Sea salt is produced at evaporation ponds near the west coast town of Tamarin.
The most recent complete USGS report on the mineral industry in Mauritius is from 2014. The most recent production statistics on the Mauritian mineral industry are from 2022.
While there are few potential mineral deposits to develop onshore Mauritius, there are at least two possible offshore development possibilities: petroleum and polymetallic nodules.
In 2012, the Mauritian government passed a bill to regulate petroleum exploration in their economic zone. However, although Mauritius and the Seychelles have an agreement to regulate their Joint Management Area on the Mascarene Plateau, there has been little actual petroleum exploration. The story about polymetallic nodules is similar. While there has been some discussion on deep-sea mining and the Mauritanian government has reiterated its claim to the resources within their economic zone, there is no publicly available information on deep-sea mining near Mauritius. As I discussed in my posting on the Marshall Islands, there is little to stop pirate operators from simply dredging up polymetallic nodules and disappearing.
Figure 6, below, links to an interactive mineral occurrence map for Mauritius.
Figure 6 – Interactive
Mineral Occurrence Map of Mauritius
Credit:
©Mindat.org
Summary
Figure 7 – Blue Bay,
Mauritius
Credit:
Z thomas,
Creative
Commons Attribution-Share
Alike 4.0 International license
That winds it up for this look at the geology and mineral industry of Mauritius. The potential for future development seems to be limited. There could be petroleum and/or natural gas offshore of Mauritius, but so far there seems to little interest. Polymetallic nodules from deep-sea mining are another possibility, but it is entirely possible that the extraction of these nodules will do little for the inhabitants of Mauritius.
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.