Rocks and Microscopy > Experimentally biocemented sand crossed polars by Ian Butler

Thin section of a 5mm diameter core of quartz sand which has been cemented using the ureolytic bacterium Sporosarcina Pasteurii. Porosity is picked out by blue dyed epoxy. The photographs have been taken using crossed polars. The loose material has been biocemented by calcite precipitation induced by the bacteria during ureolysis. Calcite crystals can be seen as small grains surrounding larger quartz sand grains and are picked out by their brigh white (high white) birefringence colours.
This gigapan is part of the production of demonstration materials for the CO2Solstock project which is supported by the EU as a Framework 7 Future Emerging Technologies Network. The specimen demonstrates the potential for microbial precipitation of calcite in porous media, with possible applications for engineering controlled permeability in geological environments.