HERITAGE

Geology and landscapes

Landscapes have a history. They reflect the history of the Earth and of humankind. We take a look at this past and at a present that shapes a certain "vision" of the future.

Paysage géologique de la région d’Atar, dans l’Adrar, en Mauritanie. © BRGM-im@gé/Nicolas Baghdadi
Geological landscape in the Atar region of Adrar, in Mauritania. © BRGM-im@gé/Nicolas Baghdadi

Nature and the structure of the subsoil, the interaction between the mantle and the lithosphere, and the shifting movements of tectonic plates have all fashioned landscapes.The principal mountain ranges are testimony to areas where two continental plates or an oceanic and continental plate have collided.

Climate too leaves its mark just about everywhere, whether in the recent volcanic activity in the Giant's Causeway in Antrim (Northern Ireland), the marks left by glaciers in the ancient crystalline base of the Norwegian fjords or the sumptuous colours of the Permian landscapes of the Gorges de Cian in France. The fascinating history revealed by these landscapes is attracting the attention of increasing numbers of people in the current climate of concern about the environment and nature. The European Geoparks network brings together 32 of these sites of considerable cultural and patrimonial interest.

Local geology also determines the nature of the construction materials that are available and that in turn lend a distinctive appearance to towns and their monuments as well as to rural architecture. One of the challenges of modern building conservation policy is to rediscover the sites from which the ornamental stone used in the local architecture was originally taken. "It is the job of an expert to identify the materials used so many centuries ago to build a particular cathedral or monument and then find the site of origin. One must also hope that some of these materials can still be used so that the elements can be obtained to conserve and restore the heritage. In addition to their cultural value, one should not forget that these riches also represent an economic asset by virtue of the tourism they generate," explains Patrice Christmann, general secretary of EuroGeoSurveys (1).

Digging down

For centuries now humankind has also shaped landscapes. Restanques, the terraces bordered by low walls of dry stones so typical of the Provencal landscape, are an example of this. They served a practical purpose, namely to protect the soils - a valuable resource - from erosion. The subsoils also soon attracted interest, their exploration leaving other marks on the landscape. To find ore and minerals buried in the Earth's crust, early industry dug galleries descending to great depths. Once the resources were exhausted or became too expensive to mine, most of the mining companies closed their pits. The considerable demand of our modern societies for construction materials (2), coupled with the extraordinary increase in power of our mechanical devices, have also transformed the natural environment creating spectacular open-cast quarries or vast expanses stripped for the extraction of alluvial gravel deposits.

Legislation - especially European legislation - is fortunately compelling operators to restore these sites when mining or quarrying stops. Today many bathers swim in lakes that were once gravel pits. These former industrial sites can even be of greater ecological value than when in their original state and form new biotopes, such as wetlands originating in zones where sand and gravel were formerly extracted.

Attacking the mountains

To meet the growing demand for metals and minerals, the mining industry is today attacking on a large scale deposits located in remote mountain areas previously regarded as inaccessible due to their relief and absence of means of communication. Unlike plains with sediment deposits, mountain ranges with their particular geology provide sources of minerals - gold, copper, silver, zinc, tungsten, etc. - created when these mountains formed at the base of former oceanic plate sub duction zones.

The degree to which these activities can scar the landscape has not failed to cause concern and the lunar-like appearance of certain former mining areas speaks for itself. The damage can nevertheless be temporary if the mining companies adhere to the principles of corporate social responsibility. If not, the result can be a change to ecosystems and loss of biodiversity. The problems created can be of all kinds, including interference with the quantity and quality of water resources, concentrations of toxic sludge charged with heavy metals, loss of vegetation cover, reduced diversity of species, and changes to the topography.

Patrice Christmann believes that "public policy must, on one hand, ensure that the conditions are created for the rational exploitation of geological resources (energy, minerals, underground water, etc.) and, on the other hand, establish a legal framework (coupled with a system of financial guarantees to prevent the environmental and social impact of illconceived mining) that is binding on operators who do not commit themselves to voluntary actions."

For the rest, at the human level, the impact on societies living in these areas can be dramatic, especially in the developing countries. The social and economic effects - if fairly distributed - certainly benefit local communities (jobs, development of local skills across a wide rage of occupations, new infrastructure and creation of services, purchase of land, reduced isolation, etc.). However, it is not always certain that the ecological and social balance will ultimately prove positive given the upheavals caused by the rapid development of mining or oil activities among populations formerly living in a balanced relationship with their environment.

"Contrasting ‘good' nature with ‘evil' industry does not help the debate in a world that we know to be lacking resources. The real question is rather how to use existing resources more effectively and what policies to develop at global level (the EU alone only having a relative influence), while respecting the quality of life," stresses the EuroGeoSurveys General Secretary.

The new ‘goldrushes'

Another cause for concern is the development of artisanal mining, which is very common in developing countries in Africa, Central and South America, and the Asia Pacific that are rich in precious minerals. This sustenance activity is of growing importance (more than 30 000 persons worldwide) and practised by poor and often itinerant communities. The direct and indirect consequences can be particularly damaging at a number of levels, including deforestation, the intensive use of mercury (harmful to health) in gold mining, child labour, prostitution and AIDS. The World Bank and UK Department for International Development (DFID) have initiated an international effort to counter these situations (3).

"It is to be hoped that the policy of securing the EU's non-energy resources, as currently being drawn up, will give the Commission the necessary means of action and will permit a review of European development aid policy in which the words ‘geology' and ‘mineral resources' are currently absent. The EU imports massive amounts of resources from the developing countries whose institutions and human resources are too weak to ensure a rational use of their resources that is compatible with the principles of sustainable development," concludes Patrice Christmann.

Christine Rugemer

  1. The Association of the European Geological Surveys - www.eurogeosurveys.org

  2. 2,5 - 3 billion tonnes a year, a mass of about 1 km3 of rock, are extracted from the EU.

  3. In particular through the CASM (Communities, Artisanal and Small Scale Mining).

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