More about the Network
Carbon from the earth’s mantle originally gave rise to life, still contributes significantly to the planet’s total carbon budget, and holds scientific interest through its relationship to primordial carbon in meteorites as well as its role in shaping the geology of the crust. There is industrial interest in obtaining minerals from the carbon-rich igneous rocks, in particular carbonatites, originally liberated from the mantle. There is also concern about the geohazards of volcanism associated with carbonatites, which include the release of carbon monoxide gas as well as mass destruction. The large-scale release of carbon dioxide through such volcanic activity also has implications for climate change, which is itself a hot topic for scientific research.
An ESF Network in this field is particularly timely as many European researchers are already working in the area, and the underlying lithospheric structure and large scale regional geology are now much better understood. Successful programmes such as EUROPROBE have contributed to increased understanding of the processes involved in liberation of mantle carbon into the earth’s crust, but the field has suffered from the typical European problems of fragmentation and duplication of effort. However there has already been considerable success in uniting the European effort through several programmes, and in particular through the creation several years ago of an email list comprising petrologists, mineralogists and geochemists working in the field in nine European countries. This ESF Network is building on such foundations by creating more focused workshops bringing together scientists from a range of disciplines to work on a clearly defined series of objectives.
Europe is especially well placed for the study of mantle carbon processes, both because of its unusual concentration of relevant geological features and because recent advances lay sound foundations for a more comprehensive study. Until recently there has been almost no attempt to consider the role of carbon-rich volcanism in the broader global carbon dioxide cycle, which is perhaps surprising given the hugely increased interest in the earth’s carbon budget with the growing fears of global warming for example. However understanding of mantle carbon has only just improved sufficiently for it to begin to be incorporated into models of the global carbon cycle, so it is only really now that the potential is there for further progress. But greater multidisciplinary expertise is now needed to make such progress possible, in particular to resolve the fundamental problem of how carbon-bearing igneous rocks were formed. Scientific progress on this front has been slow.
Such progress will help answer some of the broader questions about how mantle carbon is related to global climate and mass extinctions, where Europe has already gained a substantial body of expertise from another programme called Impact.
A major question that this Network is attempting to answer is the extent of the contribution of the "hidden carbon reservoir", i.e. mantle carbon, to the total global carbon cycle. It is known to be a factor as mantle carbon can be detected in the crust and atmosphere, but there is little understanding of the processes involved in its transport, which would enable its significance in the total carbon cycle to be assessed more accurately. It is not yet certain for example whether steady state or catastrophic processes have played the biggest role in liberating carbon from the mantle. European scientists have been working on these problems, but in too great isolation from each other. For example very few earth scientists have been aware of the significance of recent discoveries of volcanic and oceanic carbonatite rocks in Europe. Carbonatites are rare igneous rocks with more than 50% of their mass comprising carbonate minerals. The volcanic ones are particularly interesting because they reveal how carbon is transported from the mantle to the crust, and perhaps released into the atmosphere as CO2.
News/Current Status
This Network is creating the links between relevant research groups and providing a foundation for further longer term programmes, perhaps within the ESF as well as individual countries, through a series of five workshops running between 2001 and 2003. The first in April 2001 will combine forces with a meeting of the EUG in Strasbourg, setting the scene by exploring all possible aspects of global and mantle carbon, while also emphasising the importance of recent developments about carbonatites through an adjoining field workshop.
The second workshop to be held in Finland possibly September 2001 will use European expertise to evaluate the potential for commercial exploitation of carbonatite deposits. Finland was chosen for the venue because one carbonatite is already mined for phosphate there.
Then the third workshop will be held late spring 2002 in Italy, chosen because newly discovered carbonatite rocks there have proved controversial. The arguments concern whether these rocks were transferred from the deeper mantle explosively or by gentler processes. Recent claims that such processes led to mass extinctions by being catastrophic will be examined.
The fourth workshop, to be held in Edinburgh late summer 2002, will then focus on the materials that carry mantle carbon through the crust to the surface. This conference will attract a wide variety of researchers, including mineralogists, geochemists, mineral physicists, petrologists, and metamorphic mineralogists, who are unlikely to have had previous contact with the Network.
The final fifth workshop, scheduled for May/June 2003 either in Cape Verde or the Canary Islands, will tackle the global issue of the location and timing of carbon transfer from mantle to crust. This will draw on the findings of the previous four workshops and highlight promising avenues for future research, possibly within a full five-year ESF programme.
