Roland Dreesen

Carbon dioxide sequestration in the Campine Basin and the adjacent Roer Valley Graben (North Belgium): an inventory

Abstract The Campine Basin offers a variety of potential CO2 storage sites. Within the Roer Valley Graben area Triassic Buntsandstein rocks have an estimated CO2 storage capacity of several hundred million tons. Mesozoic shales and younger sediments provide adequate sealing. Westphalian D sandstones may possess storage opportunities in the southern graben area, and the karstified/dolomitized parts of the Dinantian carbonates in the western sub-basin have an estimated CO2 storage capacity of 130 × 106 tons. In places, the Dinantian reservoirs may be combined with carbonate reservoirs in the underlying Devonian strata. Sealing is provided by Namurian shales and Westphalian coals and shales. Along the western and southern edge of the basin the Dinantian reservoir is sealed by Cretaceous chalks and marls. Besides aquifers, the available coal qualifies for CO2 storage. Six Six methane target areas contain a producible enhanced coalbed methane (ECBM), volume of 53–79 × 109m3. This provides a minimum CO2 sequestration potential of 400 × 106 tons. ECBM development factors include the sedimentological setting of the coal sequence as well as changes in porosity, permeability and stress conditions induced by former mining activities. The CO2 storage capacity in abandoned coalmines is limited. Nevertheless, CO2 storage in the abandoned mines may be an option when it is combined with coalmine methane extraction or ECBM production in neighbouring areas.

The Geological and Cultural Heritage of the Caledonian Stavelot-Venn Massif, Belgium

The Stavelot-Venn inlier (also called as the Stavelot-Venn Massif) exposes a thick series of sedimentary rocks that have been intensely deformed and fractured by two succeeding orogenies (Caledonian and Hercynian). In addition, the Massif has been metamorphised into greenschists (at least at its southern border), subsequently cut by a large collapse structure (the Graben of Malmedy) and is still subjected to vertical tectonic movements. The geology of the Massif is quite distinct from that of the surrounding Devonian-Carboniferous strata. The rocks that built it, as well as their complex geological histories, created a particular landscape that is of great biological and geological interest; this has led to the creation of the High Fens Natural Park. Its subcrop encloses many peculiarities of regional, international or even global importance: e.g. manganese and molybdenum mineral deposits, slightly mineralised and ferruginous waters and sharpening stones made of ‘coticule’. The building stones extracted from the Massif (slates, quartzites) and from its borders (arkoses, sandstones) provide a characteristic look to the built environment and to other smaller heritage objects. Some relicts of the former mining activities have been used for touristic purposes (e.g. the slate quarry of Recht, the Museum of the Coticule); others have evolved into natural sanctuaries for rare or even exceptional faunas and floras, while some others have been deliberately abandoned to evolve freely. The conservation of the extensive peat bogs of the High Fens receives international attention and support. Clusters of ‘viviers’ (ramparted and closed remnants of Pleistocene lithalsas) within this peat bog landscape are unique witnesses of subarctic conditions that ruled here during the youngest ice age. The cities of Spa and Chevron are true cities of water: the former is internationally renowned, having given its name to the famous and popular spa. The natural and geological heritage assets of the Stavelot-Venn Massif are thus multiple and interrelated: stunning landscapes, interesting former mining activities, exceptional ecosystems, excellent mineral waters and attractive local building stones. However, a holistic project integrating all of the latter components has still to be launched and is waiting for regional, national and international support. The Massif is well positioned between Belgium and Germany and covers different administrative units, offering excellent opportunities for creating a cross-border Geopark.