Forum for Science, Industry and Business

Juvenile Shale Gas in Sweden - Tectonics and deep biosphere

Considering geological time scales, the occurrence of biogenic shale gas in Sweden´s crust is relatively young. An international team of geoscientists (led by Hans-Martin Schulz, German Research Centre for Geosciences GFZ) found that biogenic methane in the Alum Shale in South Sweden formed due to deglaciation around 12.000 years ago.

Fig. 1: Calcit crystals in the Alum Shale as indicators of methane formation (Photo: GFZ)

Fig. 2: Pores of nano-metre size in the Alum Shale filled by methane gas (Photo: GFZ)

Moreover, the formation processes were due to complex interactions between neotectonic activity and the occurrence of a deep biosphere. Applying a new hydrogeochemical modelling approach, the specific methane generation process was unravelled and quantified for the first time in Europe.

Around 300 million years ago the Variscan Mountain belt was formed in Central Europe. Its orogeny and uplift was coupled to extensional movements in today´s Northern Europe.

As a result, mafic magmas intruded the early Palaeozoic rock sequence and led to oil formation in the Alum Shale followed by its expulsion. Migrating bitumens impregnated the Alum Shale outside the area of thermal influence.

The melting of the up to three kilometers thick glaciers at the end of the last glaciation led to a beginning uplift of the formerly glaciated Baltic Sea region which still today rises by up to 10 mm per year. A consequence of this uplift tendency is the formation of fractures along which melting water migrated into the subsurface.

It is important to note that low contents of dissolved solids in formation water is a prerequisite for methanogenic microbes to convert soluble oil components into methane. Accordingly, methane is stored in black shale today and can be found up to approximately 100 meters depth.

Up to now, similar biogenic methane resources were exclusively known from North America which was glaciated as Northern Europe. The most prominent example is the Antrim Shale of Devonian age in Michigan.

Hans-Martin Schulz, Steffen Biermann, Wolfgang van Berk, Martin Krüger, Nontje Straaten, Achim Bechtel, Richard Wirth, Volker Lüders, Niels Hemmingsen Schovsbo, and Stephen Crabtree: „From shale oil to biogenic shale gas: Retracing organic–inorganic interactions in the Alum Shale (Furongian–Lower Ordovician) in southern Sweden.”, AAPG Bulletin, v. 99, no. 5 (May 2015), pp. 927–956, DOI: 10.1306/10221414014

Franz Ossing | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ
Further information:
http://www.gfz-potsdam.de/

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...