Publication Date:
2022-08-26
Description:
Abstract
Description:
This data collection provides digital access to data and publications of the KTB (German Continental Deep Drilling Program) project. KTB was a very detailed, long-term Earth science investigation on the structure, dynamics and formation of the Central European crust in Northeastern Bavaria, Germany (Harms, Kück 2016). With geophysical sounding and ultra-deep drilling it elucidated a crustal block at the border of a micro-continental collision zones amalgamated during the Caledonian and Variscan orogenies.
Major research themes were: i) the nature of geophysical structures and phenomena, ii) the crustal stress field and the brittle-ductile transition, iii) the thermal structure of the crust, iv) crustal fluids and transport processes, and v) structure and evolution of the central European Variscan basement.
KTB started in 1982 with pre-site selection studies and scientific objective definition followed in 1985 by site selection studies including shallow boreholes. From 1987 to 1990 a pilot borehole of 4000 m depth was drilled and fluid tests and borehole studies were conducted. In 1990 started drilling of a so-called superdeep main borehole of 9101 m depth that was reached in 1994. Again, the final drilling phase was concluded with large-scale fluid and seismic experiments.
The rocks drilled comprise metamorphic series of mafic volcanic, volcano-clastics as well as minor gabbroic to ultramafic rocks that are intercalated with leucocratic meta-sedimentary gneisses. They represent most likely a deeply subducted accretionary wedge mélange with a complex P-T-t history. The undisturbed bottom hole temperature is ~265°C.
Among the outstanding results are the following:
(1) A continuous profile of the complete stress tensor was obtained.
(2) Several lines of evidence indicate that KTB reached the present-day brittle-ductile transition.
(3) The drilled crustal segment is distinguished by large amounts of free fluids down to mid-crustal levels.
(4) The role of post-orogenic brittle deformation had been grossly underestimated.
(5) Steep-angle seismic reflection surveys depict the deformation pattern of the upper crust.
(6) High-resolution seismic images of the crust can be obtained with a newly developed technique of true-amplitude prestack depth migration.
(7) The electrical behavior of the crust is determined by secondary graphite (+/-sulfides) in shear zones. (after Emmermann und Lauterjung (1997)
Description:
Other
Description:
The data are ordered according to disciplines, wells and working groups and currently available via the original KTB site (https://data.icdp-online.org/sites/ktb/welcome.html). The DOI-referenced data publication of KTB data is in progress.
Scientific disciplines:
Borehole Measurements
Geology, Petrology, Tectonics
- Microscopy
- Lithological description of cores
- Lithological description of cuttings
- Tectonic elements
Geochemistry
- Gas analysis
- XRF, XRD analysis
- Infrared Spectrometry
- IC, ICP-AES
Petrophysics
- Density
- Porosity
- Electrical resistivity
- Natural gamma-ray activity
- Inner surface
- Permeability
- Relaxation
- Magnetic susceptibility
- Ultrasonic seismics
- Thermal conductivity
Rock Mechanics
- Compressive strength
- Tensile strength
Technical drilling parameter
Fluid/Hydraulic experiments
Hydrofrac/Seismic experiments
Keywords:
German Continental Deep Drilling Program
;
KTB
;
Bavaria
;
Windischeschenbach
;
field laboratory
;
downhole logging unit
;
geology
;
petrology
;
tectonics
;
geochemistry
;
petrophysics
;
rock mechanics
;
borehole measurements
;
drilling engineering
;
final experiments
;
hydrolaulic tests
;
presite surveys
;
dekorp iso89
;
EARTH SCIENCE 〉 SOLID EARTH 〉 EARTH GASES/LIQUIDS
;
EARTH SCIENCE 〉 SOLID EARTH 〉 GEOCHEMISTRY
;
EARTH SCIENCE 〉 SOLID EARTH 〉 GEOMAGNETISM
;
EARTH SCIENCE 〉 SOLID EARTH 〉 ROCKS/MINERALS/CRYSTALS
;
EARTH SCIENCE 〉 SOLID EARTH 〉 TECTONICS
;
In Situ/Laboratory Instruments 〉 Corers
Type:
Collection
,
Collection
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