Mining
Antarctica, like all large land masses, contains some minerals as well as oil and gas from when it was a temperate continent.
The main problems in mining lie in the cold, the ice covering land and sea, drifting icebergs which could collide with platforms, remoteness from inhabited places and the sheer cost of operations. But it's an academic question because oil prospecting and extraction has been banned, effectively for ever, under the Madrid Protocol signed in 1991.
History of exploration
The current status of mining in the Antarctic is the result of a complex history involving a variety of disciplines - science (geology), economics and the politics of international agreements.
In the 1980s the question of possible mineral (including hydrocarbons - oil and gas) exploitation was addressed by the nations of the Antarctic Treaty. They negotiated an agreement called the Convention on the Regulation of Antarctic Mineral Resource Activities (CRAMRA) which would have regulated mining should it have ever been contemplated. CRAMRA did not come into force. Instead, the Protocol on Environmental Protection to the Antarctic Treaty (Madrid Protocol) was negotiated and it includes a ban on Antarctic mining.
CRAMRA excluded icebergs as a water source because the ice was seen as a renewable resource in contrast to mineral and hydrocarbons. This article addresses minerals and hydrocarbons separately.
Minerals
Geologists at work
Photo: D. McVeigh
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Minerals have been discovered in Antarctica as a result of general geological studies. The main minerals which are known are iron oxides and coal. Minor occurrences of many others are known but are of no comercial significance.
Antarctica, like all other continents, has at its core an ancient shield, East Antarctica, composed of rocks as old as almost 4 billion years - some of the oldest rocks known on Earth. (The age of the Earth is estimated to be 4.6 billion years and thus ancient Antarctic rocks can be studied to gain insight into processes active in the early days of the Earth's history). These most ancient rocks occur very well exposed in Enderby Land at the western extremity of the Australian Antarctic Territory.
Many other rock groups formed as sequences of volcanic rocks and sediments at 2.5 to 2.8 billion years ago, and others at 1.4 billion years. Many other ages also are known.
The ancient shield is not homogeneous but can be subdivided into clearly separable units (cratons). These cratons and the boundaries between them have been the locations of much activity as the cratons have moved against one another. In other continents, the same structure and similar age relationships are known. Most of the world's mineral resources come from these cratonic units and thus it is reasonable to expect that the Antarctic shield has the same mineral resource potential as other parts of the globe. However there are some features of Antarctica that reduce dramatically the chance of mineral availability.
Firstly, 98 per cent of the continent is overlain by ice, up to 4 kilometres thick and thus very little is accessible for exploration. In the Australian Antarctic Territory, the exposure is even lower; about 0.2 per cent is exposed (20 per cent of the area of Tasmania).
Secondly, many types of minerals which are important elsewhere on Earth cannot be expected in Antarctica.
A common way of commencing mineral exploration elsewhere is to pan for gold or heavy metals or minerals in rivers. More detailed exploration includes river water sampling to locate likely ore bodies. Antarctica does not have many rivers and those that do exist are very small, seasonal and drain very small areas. Thus heavy mineral 'placer' deposits are very unlikely. Similarly, because of the different oceanographic conditions and lack of beaches, heavy mineral beach sands, so important in Australia, will not be available.
Thirdly, certain mineral occurrences such as bauxite (the ore of aluminium), some iron ores, or even some nickel bearing laterites are formed by long term leaching of a parent rock so that virtually all of the parent is altered and dissolved away, leaving an insoluble residue, commonly soft. Antarctica does not have the weathering conditions (it is too cold), nor the dissolving power (water is almost absent), and glacial activity would remove anything soft or that formed in ages past.
Another related occurrence missing from Antarctica is supergene enrichment to produce a porous iron-rich surface material known as gossan. Gossans form over some ore bodies (and very often even where no valuable ore exists at depth) particularly where the ore body may be made of sulphides of iron with inclusions of copper, gold and others minerals such as at the original site of the Mt Lyell mine in Tasmania. The gossan is often a valuable guide to an ore body at depth and covers a larger area than the ore body. A feature of such supergene enrichments is that, as the parent rocks weather through water and other action the residual gossan is enriched (hence the name) in gold and some forms of copper, including native copper. These rocks are a good source of high economic short-term mining, providing the resource to develop the parent ore body. Such supergene enrichments are absent from Antarctica because of unfavourable weathering conditions and removal by moving ice.
Thus many kinds of ores mined elsewhere cannot be expected in Antarctica. Any mineral search in Antarctica would need to find the parent ore body directly - a search for small areas in an already very small area of outcrop.
Of course, it may be that, due to the unique oceanic conditions around Antarctica, as yet unknown mechanisms may be concentrating minerals. There is no evidence of this so far.
An argument often put forward to suggest that East Antarctica is mineral-rich is based on the fact that if continents are placed in their original places in the ancient supercontinent of Gondwana, parts lie against mineral rich ancient rocks of Western Australia. Unfortunately for those who use this argument, it is invalid. Along the south coast of Western Australia is the Albany-Fraser block which has almost totally defied concerted efforts to find much mineral wealth there.
The geological story of West (Lesser) Antarctica is very different but the mineral resource potential also is low. West Antarctica is much smaller than East Antarctica but has a higher proportion as outcrop. The history is much more recent, encompassing the last 200 million years, less than 10 per cent of the age of East Antarctica. The story relates to the evolution of the Southern Pacific Ocean margin, including New Zealand and South America.
The Antarctic Peninsula, the main exposed part of West Antarctica, was formed by complex process nearly 200 million years as Pacific (and possibly Atlantic) Ocean seafloor has been subducted (lead under) the Peninsula. This process has also occurred in New Zealand and along the west coast of South America. In the process, it formed the rich copper ores of Chile and thus the Peninsula has been put forward as a potential copper province. Unfortunately for the proponents of this idea, the facts do not support it. Copper in Chile does not occur all along the west coast but only in the northern part, north of the capital Santiago.
Let us look now at some specific mineral occurrences known in Antarctica.
Coal
Coal has been found in two regions in East Antarctica - the Transantarctic Mountains and Prince Charles Mountains. The two occurrences are quite different. Those in the Transantarctic Mountains are Triassic (200 million years which is roughly the same age as the sandstones in the spectacular cliffs around Sydney), and those in the Prince Charles Mountains are 250 million years (roughly the same age as the Collie or Hunter Valley coals).
One of the Antarctic Treaty nations decided to have an assessment made of the economic potential of the Transantarctic Mountains coal. The nation hired a consultant, from Australia as it happens, to examine the area and produce a report. The consultant went to Antarctica briefly and returned; his advice was not to waste money on having an appraisal done. The coal is low quality (high moisture, high ash content), thin and discontinuous. With ample supplies worldwide, there is no foreseeable economic value. Much better coals elsewhere on Earth are not yet exploited.
The Prince Charles Mountains coals are in a thicker, more continuous seams of quite good quality coal. If these seams were in Australia, close to a major user, they may be exploited.
In Antarctica, the coals are a long way from a market, very distant from any infrastructure (city, roads, ports, population) and are not of any economic significance in the foreseeable future.
Iron Ore
Boulders of Banded Iron Formation (BIF) are widespread in glacial debris of East Antarctica and it is clear that BIFs are common but mainly under the ice. At Mt Ruker in the Prince Charles Mountains, BIF is known in outcrops. BIFs are known from every continent (including the Pilbara region of Western Australia) and are a major source of the world's iron.
Most BIFs formed about 2 billion years ago when oxygen first started to accumulate in the atmosphere. The BIF at Mt Ruker is quite extensive and has been traced under the ice for over 100 kilometres using magnetic methods. Unfortunately for those who would exploit this resource, the Mt Ruker ore is very remote from infrastructure, but even if close to the infrastructure, it would not be exploited because it contains only about 35 per cent iron, unlike the Pilbara region where 60 per cent is the lowest grade mined. As with coal, there is no foreseeable use for this material.
It has been said that if the Mt Ruker iron ore and Prince Charles Mountains coal occurred together next to a major market such as Chicago, they would be usable.
Chromium
One region in East Antarctica - the Dufek Massif - has been identified as a possible source of chromium, but the case is very weak. The Dufek Massif is a large area where, 170 million years ago, there was an intrusion of magma (molten rock below ground level) which cooled and crystallised where it now is. The intrusive event had very widespread effects, extending from South Africa, through the Transantarctic Mountains to Tasmania and Kangaroo Island (but not the Australian mainland) to form the rocks of the Tasmanian Central Highlands and such areas as the Organ Pipes on Mt Wellington. In most areas the rocks are 350 meters thick and lay flat with a vertical columnar structure (hence Organ Pipes). In the Dufek Massif, while part of the same intrusion, the rock differs in being several kilometres thick, thus requiring a much longer time to cool and crystallise.
It has been proposed that the long crystallisation allowed chromium oxide to crystallise and sink, forming an exploitable layer of chromite at the base of the magma chamber. No such chromite layer has been seen, nor drilled for. The potential is purely hypothetical.
Chromite is plentiful, even if not exploited, elsewhere on Earth. There is no reason why anyone should need to venture to Antarctica to exploit it (if it exists).
Seafloor Manganese Nodules
In many areas of the world oceans there is a dense layer (sometimes a pavement) of black, manganese and iron oxides, usually made of nodules about golf-ball size or a little larger. They also contain more valuable elements such as copper, nickel and cobalt.
Such nodules or pavements occur near Antarctica. The value of this material has not yet proved commercial by seafloor mining or dredging anywhere, let alone near Antarctica. There is a systematic change in value making tropical nodules considerably more valuable than polar nodules. Thus the Antarctic nodules, while not formally evaluated, would appear to be the least valuable of the nodule occurrences. Even where they are richest elsewhere on Earth, they have not proved commercial.
In Summary, there is no mining in Antarctica at present and it is prohibited by international law anyway. With the legal situation and the abundance of minerals presently available more cheaply elsewhere, it is difficult to imagine anyone wanting to mine in Antarctica in the foreseeable future.
Minerals, as discussed here, are non-renewable resources and the question is sometimes raised that we will one day run out elsewhere - and need to go to Antarctica as a source. There may be some cases where this will prove to be so, although it is difficult to identify any mineral resource for which this could be true. The world runs on an economic basis and when any resource becomes too expensive, cheaper alternatives usually are found. There also is a major effort to make things recyclable nowadays. Look at the family car. There have been major changes in recent years in the materials used to manufacture a car. Much is now fibreglass rather than metal and most can, and will, be recycled.
Hydrocarbons
Hydrocarbons - oil and gas - are dominantly the product of maturation of organic material incorporated in sediments that accumulate in the ocean, lakes and river systems. Approximately 1 per cent of sediments is organic matter - remains of plant and animal material, very dominantly from plant material.
Land plants have strengthening fibres (wood) and waxy covering (cuticle) to prevent them from drying out. Aqueous plants - algae and unicellular plants of the phytoplankton - do not need this strengthening or coating and, as a result, land and aqueous plants have a different chemistry, leading to different products of maturation.
As a gross generalisation (with many exceptions) sediments deposited in lakes and the sea (in an aqueous environment) give rise to oil (perhaps with a little gas) whereas those deposited in major river systems (similar to the sediments forming in the channel country of central Australia) give rise to gas. This generalisation holds true for the gas of the Northwest Shelf (Triassic river sediments) and oil in Barrow Island (Cretaecous marine) and Gippsland Basin (Tertiary marine).
The Maturation Process
For maturation to occur and useful hydrocarbons to be generated, the organic matter needs to be buried and subjected to raised temperatures for geological time. Normally, burial to 3 kilometres or so is needed and a temperature of 80-200C. If temperatures get higher than 120C, oil breaks down to gas and even aqueous sediments then produce gas. If the temperature exceeds 200C for any significant time, even the gas changes and methane (the dominant part of natural gas) reacts with steam to produce carbon dioxide. At this point the gas is of little commercial value and geologists would recommend that drilling stop if evidence of these temperatures is found.
Most oil and gas occurs in geologically young rocks, 160 million years or younger. While older oil and gas exists, the comments here ignore them because they are rare in the Antarctic, are of such a type as to be unlikely sources, or because they have been strongly folded and heated since formation and any possible hydrocarbons destroyed.
Onshore Antarctica can be ignored as a potential source of oil or gas because so little outcrop is known, and what is known is older, highly deformed rocks that have been subject to high temperatures We should then look at the situation offshore where we require enough sediment thickness to have been deposited in a basin form. We know little of the geometry of Antarctic sediments. There has been reconnaissance offshore geophysical study and we have a very rough idea of basin configuration for much of the Antarctic margin, but there are large areas for which almost nothing is known.
The potential for offshore oil or gas is closely linked to sediments formed as the supercontinent Gondwana broke up millions of years ago.
It is clear that in many areas, sedimentary basins formed and that sediment thickness is enough that exploration would occur if the situation existed anywhere else on Earth. Very little is known of the geometry, composition or structure of these sediments.
There has been no attempt at commercial drilling and the only drilling that has been done has been for scientific purposes by the Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP) and by specific projects in the Ross Sea. These all have avoided any circumstance where oil or gas would be predicted, for safety and environmental reasons.
Deep Sea Drilling Project activity in the early 1970s did encounter traces of gas in the Ross Sea and drilling ceased. No other drilling-based oil or gas shows are known from the Antarctic.
In Bransfield Strait, on the western side of the Antarctic Peninsula, German surface sediment sampling recovered thermogenic hydrocarbons (generated by heat), probably modern organic material modified by high heat flow over a modern seafloor spreading centre where heat flow from below is high.
Onshore Antarctica has sedimentary basins but they are under thick ice and they have not been delineated adequately nor is much known of the rocks that fill them.
In summary, all other continents have oil and gas and it is likely that the Antarctic does also, but little is known of the hydrocarbon potential and there is very little incentive to pursue the matter because the economics of exploitation are decidedly negative. Also, the parts of other continents that were adjacent to Antarctica have not proved very productive and perhaps this would reduce the incentive to explore.
Economics
Even if the rocks around Antarctica do contain oil or gas, it is highly unlikely that they could ever be exploited commercially. It has been estimated by reliable authorities that oil would have to cost well over US$200 per barrel (42 US gallons, 35 imperial gallons or 160 litres) were it to be found in viable quantities. In the last two years, the normal price per barrel has been US$60, about a quarter the cost of getting it from Antarctica.
In known sources, there is certainly several decades of reserves and thus no pressure to develop Antarctic oil. The situation for gas makes Antarctic exploitation even less likely.
Before Antarctic hydrocarbons become commercial, another economic hurdle has to be overcome. Oil shale is becoming become economically viable and opens up a vast potential resource much cheaper than Antarctic hydrocarbons. Perhaps solar and wind power (also nuclear) become more attractive.
Thus it is highly unlikely that there will be any genuine interest in exploiting Antarctic hydrocarbons in the foreseeable future for economic reasons. In addition there is an international agreement to ban such activities.
Non-economic reasons, such as a major war or the desire to have secure emergency resources regardless of cost, could put pressure on all Antarctic resources but since the World War II the world's diplomats have been very successful in preventing such pressures from emerging. The Antarctic Treaty has been one of the most successful of those agreements. The only reasons for development could be either to ensure a supply at whatever cost or to show that it can be done. There seems to be no justification for either approach at present.
