The UGOE along with UEG are currently involved in the conversion of the University’s natural gas power plant that supplies the campus with heating, into a geothermal power station. To do this, we must first understand what the subsurface looks like at around 5000m depth, as this is where we expect to reach the target temperature. From our current knowledge, we are expecting to find complexly deformed meta-sedimentary rocks, therefore one of the methods we are currently focusing on for this characterisation is an analogue study in the Harz Mountains, in central Germany. Using a combination of classical fieldwork and 3D and digital data acquisition, we can begin to understand the structures we are dealing with from the large scale (10-100m), down to the micro-scale.
UGOE in the Field
One of the main focuses over the summer period for UGOE was the collection of drone images from as many outcrops as possible. These drone images can be used in multiple different ways for data collection in both 2D and 3D. Over the course of two weeks in the Western Harz Mountains, our PhD student Katie Ford and Bachelor student Fabian Rehmann found 29 outcrops that showed a number of different deformational styles. The majority of which were then photographed using a DJI Phantom 4 drone. These images are then processed in Agisoft Metashape, which creates a 3D model from the photographs taken using the drone. These models can then be used for many purposes but the main focus is for the characterisation of the fracture network, how fractures interact with each other in different lithological and structural settings.
Another important aspect of fieldwork is sample taking. This allows us to analyse more closely the smaller scale structures as well as the details of what the rocks are actually composed of. We can do this by creating thin sections, which can be analysed under a microscope. Samples in the form of drill cores were also collected with colleagues from TuDa, for analysis of the petrophysical properties of the different rock types.