Deep-Sea Dreams vs. Land-Based Realities: Why Türkiye's Manganese is the Smarter Bet

A New Frontier of Resource Competition

The global economy is undergoing a seismic transformation driven by the transition to clean energy technologies. Lithium-ion batteries, wind turbines, solar panels, and electric vehicles require vast quantities of critical minerals such as cobalt, nickel, manganese, copper, and rare earth elements. These minerals, essential for decarbonization and electrification, have become the new strategic commodities of the 21st century.

In this race for critical raw materials, attention has increasingly turned to the seabed. Proponents of deep-sea mining argue that the abyssal plains of the world's oceans — particularly the Clarion-Clipperton Zone in the Pacific — contain billions of tons of polymetallic nodules rich in manganese, nickel, cobalt, and copper.

On April 24, 2025, President Donald J. Trump signed a historic Executive Order titled “Unleashing America's Offshore Critical Minerals and Resources,” aggressively positioning the United States to dominate seabed mineral exploration. The Executive Order called for:

• Accelerated permitting and exploration.

• Development of domestic seabed mineral processing.

• Strengthening of alliances to counter China's influence in critical mineral supply chains.

• Creation of strategic seabed mineral stockpiles.

The Order reflects a broader strategic shift among advanced economies toward securing critical mineral supply chains at all costs — even if it means venturing into the largely unknown and potentially fragile ecosystems of the deep ocean.

Yet beneath the surface optimism lies a sobering reality: deep-sea mining remains an unproven, risky, environmentally controversial, and extremely costly endeavor.

While policymakers dream of harvesting minerals from the ocean floor, an ancient ocean — the Tethys — has already left behind critical mineral riches accessible on land, in the Anatolian Peninsula of Türkiye.

In this article, we explore in depth:

• The promises and perils of deep-sea mining.

• The story of Nautilus Minerals and the Solwara 1 project: the world's first and most infamous failed deep-sea mining venture.

• The geological legacy of the Tethys Ocean, whose closure created mineral-rich deposits across Anatolia.

• A comprehensive comparison of deep-sea mining versus Türkiye's land-based manganese-nickel-cobalt deposits.

Ultimately, we argue that Türkiye’s Tethys-originated land deposits offer a far more logical, sustainable, and economically viable pathway to critical mineral security than gambling on the ocean floor.

Deep-Sea Mining: The Seductive Promise and Harsh Realities

The Theoretical Appeal of Deep-Sea Mining (DSM);

The seabed is often portrayed as an untouched frontier teeming with mineral wealth. Vast fields of polymetallic nodules cover millions of square kilometers, particularly in the Pacific Ocean’s Clarion-Clipperton Zone (CCZ). Nodules lie unattached on the seafloor, suggesting — in theory — that mining could be less disruptive than terrestrial mining.

Seafloor massive sulfides (SMS) around hydrothermal vents offer rich concentrations of copper, gold, silver, and zinc.
Cobalt-rich ferromanganese crusts on seamounts harbor valuable quantities of cobalt and rare earth elements.

DSM is positioned by its advocates as:

• A solution to supply-chain vulnerabilities, particularly vis-à-vis China's control over critical mineral refining.

• A potential way to decouple mineral extraction from human communities and reduce social conflicts associated with terrestrial mining.

• A futuristic method of ensuring resource availability for green technologies without deforestation, tailings dams, or land degradation.

In the abstract, DSM appears to promise a mineral bonanza without the terrestrial costs.

The Reality Check: Technical, Economic, and Environmental Risks

However, reality has been far less forgiving.

Technical Risks

• Operating at abyssal depths (~4,000-6,000 meters) demands highly complex, novel technologies for collecting, lifting, and processing seabed materials.

• No commercial deep-sea mining operation has yet been successfully conducted at scale.

• Pilot tests have revealed major challenges in equipment reliability, ore recovery, and handling sediment plumes.

Economic Risks

• Capital expenditures for a typical polymetallic nodule mining project are estimated at $1.5-2 billion USD — comparable to a major offshore oil field.

• Commercial viability is highly sensitive to volatile global metal prices, regulatory uncertainty, and unproven production models.

• Potential royalties, benefit-sharing obligations under the United Nations Convention on the Law of the Sea (UNCLOS), and reputational risks increase financial unpredictability.

Environmental Risks

• Sediment plumes generated by mining activities could smother deep-sea ecosystems and propagate over hundreds of kilometers.

• Destruction of ancient habitats (e.g., abyssal sponge fields, hydrothermal vent communities) could lead to permanent biodiversity loss.

• Release of heavy metals from disturbed sediments could impact the mid-water column, a critical zone for global carbon cycling.

• Scientific consensus increasingly recognizes that deep-sea ecosystems recover extremely slowly, if at all, after disturbance.

Social and Legal Risks

• Numerous countries (France, Germany, Chile, Canada, and others) and over 800 marine scientists have called for a moratorium or precautionary pause on DSM.

• The legal framework governing the seabed beyond national jurisdictions — under the International Seabed Authority (ISA) — remains incomplete, further heightening investment risk.

Nautilus Minerals and the Collapse of the Deep-Sea Dream: A Cautionary Tale

If deep-sea mining were as easy, profitable, and sustainable as its proponents claim, Nautilus Minerals would have been the first great success story. Instead, it became the industry's most sobering cautionary example.

The Rise: The Solwara 1 Project

Founded in 1997 in Canada, Nautilus Minerals was the first company to seriously pursue commercial-scale deep-sea mining.
Its flagship project, Solwara 1, was located 1,600 meters below the Bismarck Sea, within Papua New Guinea’s Exclusive Economic Zone (EEZ).

Solwara 1 targeted Seafloor Massive Sulfide (SMS) deposits formed by hydrothermal vent activity — rich in copper (up to 7%), gold (up to 20 g/t), and silver.
By 2011, Nautilus had secured the world’s first commercial seabed mining license and appeared poised to inaugurate a new mining frontier.

The company projected that:

• It could mine high-grade ore without conventional underground operations.

• Seabed mining would be "greener" — no tailings dams, no displacement of communities.

• The technological hurdles were manageable through custom-built remotely operated vehicles (ROVs) and a specially designed production support vessel.

Investor excitement was palpable. Early shareholders included mining giants such as Anglo American and a significant equity stake from the Papua New Guinea (PNG) government itself.

Nautilus became a poster child for seabed mining’s future.

The Fall: Financial Collapse and Environmental Backlash

Reality soon intervened — harshly.

Technical Setbacks

• Construction of the specialized Production Support Vessel was delayed and plagued by cost overruns.

• Integration between seabed mining tools (cutters, suction heads) and lifting systems (riser pipes) faced unforeseen engineering complications.

• Testing of seabed equipment revealed challenges in maneuverability, reliability, and recovery of material in extremely difficult conditions.

Financial Instability

• Development costs spiraled beyond early estimates.

• Anglo American pulled out in 2018, writing off a $70 million investment.

• Nautilus was unable to secure replacement funding as investor confidence eroded.

• By February 2019, Nautilus sought creditor protection under Canada's Companies’ Creditors Arrangement Act (CCAA).

Community and Political Opposition

• Coastal communities in Papua New Guinea, fearing impacts on fisheries and ecosystems, organized legal challenges.

• The Alliance of Solwara Warriors, alongside environmental NGOs, mounted an effective public campaign highlighting the risks and uncertainties of the project.

• It was revealed that environmental impact assessments (EIAs) were incomplete, based on insufficient baseline data, and lacked independent scientific review.

Bankruptcy and Aftermath

• In August 2019, Nautilus entered liquidation.

• Its assets were sold for a fraction of their initial value to Deep Sea Mining Finance Ltd — a holding company tied to its former shareholders.

• The PNG government, which had invested approximately $125 million USD into the project, lost nearly all of it — a significant blow to its national budget.

• Local communities and global observers declared Solwara 1 a "textbook case" of how not to launch seabed mining.

Today, Nautilus serves as a stark reminder:

• Deep-sea mining is not merely a technological challenge; it is a multidimensional high-risk venture encompassing environmental, financial, regulatory, and social pitfalls.

Türkiye’s Ancient Ocean Legacy: Land-Based Manganese-Nickel-Cobalt Deposits from the Tethys Ocean

The Tethys Ocean: A Geological History

Over 250 million years ago, the supercontinents of Gondwana and Laurasia were separated by a vast body of water: the Tethys Ocean.
For tens of millions of years, the Tethys served as a cradle for hydrothermal activity, sedimentation, and the formation of deep-sea mineral deposits — much like today’s Clarion-Clipperton Zone.

During the late Mesozoic and early Cenozoic eras, powerful tectonic forces gradually closed the Tethys Ocean.
In this process:

• Fragments of ancient seafloor — including ophiolites (sections of oceanic crust) and radiolarian cherts (silica-rich deep-marine sediments) — were uplifted and emplaced onto continental margins.

• Hydrothermal and hydrogenous manganese deposits, originally formed on the ancient seabed, were preserved in the rocks now exposed across the Anatolian Peninsula.

Thus, the geological record of Türkiye holds within it the fossilized mineral wealth of an ancient deep-sea environment, now accessible on land.

The Manganese Deposits of the Yozgat Region

The Yozgat Province in central Türkiye offers a striking example of this geological legacy.

Extensive studies — including those you shared (Öksüz et al., Koçak et al.) — document manganese mineralizations at locations such as:

• Eymir

• Derbent

• Büyük Mahal

These deposits:

• Occur within Lower Cretaceous radiolarian cherts — the same type of silica-rich sediments hosting modern abyssal manganese nodules.

• Exhibit banded and lenticular textures, similar to deep-sea ferromanganese crusts and nodules.

• Are spatially associated with ophiolitic units — ancient slices of oceanic crust thrust onto land during Alpine orogenic (mountain-building) events.

The manganese ores display mineralogical assemblages characteristic of deep-sea origin:

• Primary minerals: Pyrolusite (MnO₂), Braunite (Mn₂⁺Mn₆³⁺SiO₁₂), Manganite (MnO(OH)), Magnetite (Fe₃O₄).

• Accessory minerals: Goethite (FeO(OH)), Psilomelane (BaMn₉O₁₆(OH)₄).

Importantly, geochemical studies reveal:

• High manganese content (MnO₂ > 40 wt%).

• Enrichments of nickel (Ni) and cobalt (Co) — two metals critical for battery technologies.

• Rare earth element (REE) signatures, including negative cerium anomalies, indicative of hydrogenous formation in an oxidizing marine environment.

These features closely mirror the mineralogical and geochemical profiles of modern deep-sea nodules — but crucially, the Anatolian deposits are on land, where they can be mined far more easily and responsibly.

Geological Mechanisms: Hydrothermal-Hydrogenous Formation

The formation process of these manganese deposits involves two intertwined mechanisms:

1. Hydrothermal Precipitation:

   • During mid-ocean ridge activity in the Tethys Ocean, hot, metal-rich fluids vented from the seafloor.

   • These fluids deposited manganese, iron, and trace metals onto the sediment-water interface.

2. Hydrogenous Accretion:

   • Slow precipitation of metals directly from seawater onto existing particles (chert, volcanic rocks) over millions of years.

   • This process enriched the deposits in nickel, cobalt, and rare earth elements.

Thus, the Yozgat manganese deposits represent ancient analogues of the hydrothermal-hydrogenous systems currently targeted for deep-sea mining.

Strategic Advantages of Türkiye’s Land-Based Deposits

Beyond geology, Türkiye’s Tethys-derived manganese deposits offer multiple strategic advantages:

• Accessibility: Located within a stable, well-connected region with modern infrastructure (roads, ports, energy).

• Lower Operational Costs: Open-pit or shallow underground mining methods are feasible, dramatically cheaper than abyssal mining.

• Environmental Control: Land mining allows for proper environmental impact assessments, rehabilitation, and monitoring — none of which are reliably possible 6,000 meters below the ocean.

• Faster Project Development: Regulatory frameworks for land-based mining are clear and established in Türkiye, unlike the uncertain international seabed regime.

• Geopolitical Stability: Türkiye’s position as a bridge between Europe and Asia enhances supply chain security and diversification.

In essence, Türkiye offers the benefits of deep-sea minerals — without the abyssal risks.

Side-by-Side Strategic Comparison: Deep-Sea Mining vs. Türkiye’s Tethys-Origin Land-Based Manganese Deposits

Now that we have explored both the emerging ambitions around deep-sea mining (DSM) and the ancient mineral legacy of Türkiye’s Anatolian Peninsula, it is time to directly and systematically compare the two approaches.

Below is a comprehensive strategic comparison, taking into account the critical dimensions of technical feasibility, economic costs, environmental risks, social factors, and long-term sustainability.

Why the Smart Future Lies in Türkiye’s Ancient Lands, Not the Abyss

As nations urgently search for solutions to secure critical minerals essential for the green energy transition, two fundamentally different pathways present themselves:

• One ventures into the unknown, seeking to mine the deepest parts of the Earth’s oceans — a realm of immense environmental, technical, and regulatory uncertainty.

• The other embraces the legacy of ancient oceans that already gifted humanity mineral wealth, now preserved on land — accessible, studied, and manageable.

After carefully examining both options, the choice becomes clear: Türkiye’s Tethys Ocean-derived land-based manganese, nickel, and cobalt deposits represent a vastly superior opportunity compared to deep-sea mining.

Türkiye: Harnessing the Gifts of the Ancient Tethys Ocean

Türkiye's geological history offers a natural solution to today's critical mineral demands.
The closure of the ancient Tethys Ocean during the Alpine orogeny preserved manganese-rich mineralizations in the ophiolitic complexes and radiolarite cherts across the Anatolian Peninsula.

These deposits:

• Mirror the mineralogy and geochemistry of modern deep-sea nodules — rich in manganese, nickel, and cobalt.

• Reside on stable continental landmasses, where exploration, mining, and environmental stewardship are practical and proven.

• Benefit from Türkiye’s strategic geographic position, strong infrastructure, and established mining expertise.

Rather than speculating billions of dollars on experimental technologies in fragile ocean ecosystems, countries and companies can invest more wisely in Türkiye’s accessible critical mineral resources — with lower cost, lower risk, faster timelines, and greater environmental responsibility.

Deep-Sea Mining: A High-Stakes Gamble with Planetary Consequences

The allure of deep-sea mining rests on an enticing but deeply flawed narrative: that we can unlock mineral riches without consequence.

The truth is sobering:

• Technological barriers remain formidable. No full-scale commercial deep-sea mining has yet succeeded.

• Economic models are precarious, vulnerable to fluctuating metal prices, high operating costs, and uncertain regulatory regimes.

• Environmental impacts are poorly understood but potentially catastrophic — threatening ancient marine ecosystems and vital carbon sinks.

• Public opinion is increasingly turning against seabed mining, with calls for moratoriums from governments, scientists, and global brands.

The fate of Nautilus Minerals — once the bright star of the seabed mining industry, now a cautionary tale of collapse — underscores the real dangers of overestimating technological capabilities while underestimating environmental and social risks.

Final Word: A Future Built on Solid Ground

The green transition demands metals — but it also demands wisdom. We stand at a crossroads: between disrupting Earth’s final ecological frontiers, or wisely harvesting the mineral gifts already bequeathed to us by ancient oceans now uplifted onto dry land. In choosing terrestrial critical minerals, we choose prudence over peril, sustainability over speculation, and resilience over recklessness.

The smarter, safer, and more strategic choice is clear.
The future of critical minerals lies not beneath the abyss, but beneath our very feet.