KTB Deep Crustal Lab of GFZ

The KTB Deep Crustal Laboratory of GFZ Potsdam (KTB-DL) is a worldwide unique research site for a wide variety of experiments, tests and measurements under in-situ borehole conditions. The constellation of two very deep boreholes in crystalline rocks close to each other (200 m) with easy accessibility and full technical infrastructure allows deep borehole experiments at reasonable costs. The KTB site is located in Windischeschenbach, Oberpfalz, Bavaria in southeastern Germany. Management, organization and most on-site services are provided by the 'Center for Scientific Drilling at GFZ (Wissenschaftliches Bohren - WB). High temperature and pressure (T > 170 °C, p > 65 MPa) in the boreholes offer ideal test beds for high-tech developments and testing of new scientific and technical methods.

The KTB-DL Site

During the KTB project (1987-1995) two deep boreholes were drilled, the so-called pilot hole (KTB-VB, 4 km) and the ultra deep main hole (KTB-HB, 9.1 km). Both wells are nearly completely cased. The VB is accessible to nearly bottom hole. At KTB is the unique constellation of two deep boreholes very close together at one site. The distance at surface between the two wells is only 200 m, figure 1. The KTB boreholes are situated in the crystalline metamorphic rocks of a Hercynian continental collision zone. The dominating rock types are paragneisses and metabasites. The rocks experienced at least two Palaeozoic metamorphic cycles and intense post-orogenic crustal stacking during upper Carboniferous and upper Cretaceous, figure 2. The boreholes are characterized by generally steeply dipping foliation, >60° and, below 5000 m, strong to extreme borehole wall breakouts. The KTB HB shows very low inclinations (< 2°) down to 7400 m, below the inclination reaches higher values as is in the entire VB (> 5°), figure 3. The platforms surrounding the two boreholes are completely paved and therefore accessible also with heavy trucks, figure 4.


Profile photo of  Dipl.-Geophys. Jochem Kück

Dipl.-Geophys. Jochem Kück
Centre for Scientific Drilling

Building A 69, room 306
14473 Potsdam
tel. +49 331 288-1087

Address KTB

Am Bohrloch 2
92670 Windischeschenbach

Website (Kopie 1)

further information to the data

Click on the left site "Data"