165 documents found in 275ms
# 1
KTB, WG Geochemistry
Abstract: The qualitative and quantitative phase analyses were performed in the KTB field laboratory by x-ray powder diffraction using SIEMENS D 500 diffractometer. During early stages of the KTB project a new method for quantitative phase analysis was developed (see references below). The method is based on the comparison of the diffraction spectrum of the unknown sample with those of pure minerals. The powder diffraction data of the minerals are stored in a database built up of 250 natural minerals separated from various types of igneous and metamorphic rocks. The complete analyses (radiation: Cu K alpha, lambda: 1,5405Å, stepwidth: 0,01°, counting time 2 sec/step, angle 2-80°) was carried out automatically including computations. The results of this quantitative phase analysis were used e.g. to check thin section petrography (and vice versa) and to construct a \"mineralogical rock composition log\".
# 2
KTB, WG Geophysics
Abstract: In the laboratory, the gamma radiation is measured by a sodium iodtite (NaI) scintillation detector (cores and cuttings) and by a germanium (Ge) semiconductor detector (cuttings). The cuttings are measured in air tight Marinelli-beakers with a volume of 250 cm3. For the core measurements a special, automatically operating equipment with three NaI detectors is used. A description of this apparatus is given in Wienand et al. (1989). The principle of measurements with the Ge-detector is described by Bücker et al. (1991).The measured spectra are calibrated by a standard of Luvarovite (NIM-L, South African Bureau of Standards). The influence of the local terrestrial radiation on the measurements has been corrected. Especially for the core measurements a calibration procedure has been performed for geometric corrections (core diameter and length). In general, a measuring time of 12 h for the NaI-detector and 2 h for the Ge-detector was chosen.
# 3
KTB, WG Geophysics
Abstract: The thermal conductivity on cores is measured in two steps (see Pribnow 1994). First, one face end of the core is sawed and polished. The half space line source is pressed against this preparated face (without further contact medium like water) by a computerized device. The position of the heat source is varied in 15 degree intervals around one semicircle. At each position, 3 repeating measurements are performed. The line source azimuth of the lowest measured thermal conductivity is the strike of the foliation plane. On the other hand, the thermal conductivity is maximal parallel to that direction. This apparent paradox can be explained by the experimental method, because the measurement plane is perpendicular to the orientation of the line source (Pribnow 1994).In a second step a calotte plane perpendicular to the strike of foliation is prepared. A second series of thermal conductivity measurements in 15 degree intervals ...
# 4
KTB, WG Geochemistry
Abstract: Geochemical Analysis of Anions of Mud Samples of the KTB Main Hole HB1h.
# 5
KTB, WG Geochemistry
Abstract: Geochemical Analysis of Anions of Mud Samples of the KTB Main Hole HB1a.
# 6
KTB, WG Geophysics
Abstract: The thermal conductivity on cores is measured in two steps (see Pribnow 1994). First, one face end of the core is sawed and polished. The half space line source is pressed against this preparated face (without further contact medium like water) by a computerized device. The position of the heat source is varied in 15 degree intervals around one semicircle. At each position, 3 repeating measurements are performed. The line source azimuth of the lowest measured thermal conductivity is the strike of the foliation plane. On the other hand, the thermal conductivity is maximal parallel to that direction. This apparent paradox can be explained by the experimental method, because the measurement plane is perpendicular to the orientation of the line source (Pribnow 1994).In a second step a calotte plane perpendicular to the strike of foliation is prepared. A second series of thermal conductivity measurements in 15 degree intervals ...
# 7
KTB, WG Geochemistry
Abstract: In the complete KTB-VB and in in the KTB-HB down to a depth of 3003 m the gas phase was released and collected by twirl degassers attached in front of the mud shakers. This open system led to gas losses as well as air contamination. Therefore results obtained down to this depth have only qualitative character. After casing the KTB-HB to a depth of 3003 m a bypass system was installed at the BOP (blow-out preventer) 50 cm below the flow line. A constant part (about 100 l/min) of gas-bearing drill mud is pumped through the bypass directly to a twirl degasser which is isolated against atmosphere. To prevent air contamination or sucking off drill mud the pressure in the gas trap is balanced by charging argon. The released gas phase is completely sucked off and led through a heated hose (in order to prevent water condensation or freezing) to the logging unit and there parallel to the measuring systems gaschromatograph, mass spectrometer and radon logging device.
# 8
KTB, WG Geochemistry
Abstract: Cuttings were crushed in a tungsten carbide ball mill for 25 min; while core samples were crushed in a tungsten carbide jaw breaker and then processed in the same way as the chip material. The resulting powder samples (max 0.06 mm size) were dried at 105°C, 3 gr selected and mixed with 2.5% Moviol solution and finally pressed under 40 kN into alumina rings. These standardized pellets were used for both, XRD and XRF measurements.For the determination of major and trace elements a fully automated wavelenght-dispersive XRF device (SIEMENS SRS 303 AS) was used in the field laboratory. The standard measuring operation comprised 11 major elements (SiO2, TiO2, Al2O3, Fe2O3 total, MnO, MgO, CaO, Na2O, K2O, P2O5, S) and 12 traces (Rb, Sr, Y, Zr, Nb, Cr, Ni, Zn, V, Cu, Th, U). Element concentrations were calculated by setting up calibration curves computed with more than 40 international natural rock standards.
# 9
KTB, WG Geophysics
Abstract: In general, four-electrode devices are used to measure the resistivity on original (unprepared) cores and on mini cores drilled from these original cores. The in-phase and the out-of-phase signal is measured and therefore the complex resistivity is determined. All measurements are performed under surface conditions (room temperature and atmospheric pressure). Four point like electrodes are situated at the core surface along a semicircle in a plane perpendicular to the core axis. The two current electrodes are opposite to each other. The electrodes are in contact to the sample by a porous plastic material soaked with 0.1 molar NaCl solution. Voltage and current is measured by a lock-in-amplifier at 120 Hz frequency. Due to high contact resistances, only the magnitude of complex resistivity is used. By computer controlled rotating of the core and moving of the electrode arrangement along the cores z axis, resistivity as a function of azimuth and length is measured.
# 10
KTB, WG Geochemistry
Abstract: The qualitative and quantitative phase analyses were performed in the KTB field laboratory by x-ray powder diffraction using SIEMENS D 500 diffractometer. During early stages of the KTB project a new method for quantitative phase analysis was developed (see references below). The method is based on the comparison of the diffraction spectrum of the unknown sample with those of pure minerals. The powder diffraction data of the minerals are stored in a database built up of 250 natural minerals separated from various types of igneous and metamorphic rocks. The complete analyses (radiation: Cu K alpha, lambda: 1,5405Å, stepwidth: 0,01°, counting time 2 sec/step, angle 2-80°) was carried out automatically including computations. The results of this quantitative phase analysis were used e.g. to check thin section petrography (and vice versa) and to construct a \"mineralogical rock composition log\".
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