Magnetic Susceptibility of Mini-Cores of the KTB Pilot Hole VB1a

The magnetic susceptibility is measured by an inductive AC device (BARTINGTON). The sample is placed inside a coil which generates an alternating magnetic field. The applied frequency is 460 Hz (cuttings, 25.4 mm mini cores), 565 Hz (cores) or 1470 Hz (15 mm mini cores) respectively. A shift in the oscillator frequency is a measure for the magnetic susceptibility of the sample. The applied magnetic field strength is 80 A/m (RMS) and appr. 2 times the total earth magnetic field strength in the KTB area (=38 A/m). The measurement field is lower than the field which is necessary for magnetic saturation and allows therefore to measure the initial susceptibility. The used sensors are insensitive to the electrical conductivity of the samples. Except the determination of the temperature dependent susceptibility, all measurements are done under surface conditions (room temperature and atmospheric pressure).

磁化率通过感应式交流设备（BARTINGTON）完成测量。将样品置于产生交变磁场的线圈内部。施加的交变磁场频率分别为460 Hz（岩屑、25.4 mm微型岩芯）、565 Hz（岩芯）及1470 Hz（15 mm微型岩芯）。振荡器频率的偏移量可用于表征样品的磁化率。施加的磁场强度为80 A/m（均方根值，RMS），约为KTB区域地球总磁场强度（38 A/m）的2倍。该测量磁场低于磁饱和所需的场强，因此可用于测定样品的初始磁化率。所用传感器对样品的电导率不敏感。除温度相关磁化率的测定外，其余所有测量均在地表条件（室温及大气压力）下完成。