Detail of MeasurementNatural remanent magnetization (NRM):
During the measurement of NRM, a cylindrical specimen is manually rotated 6 times in the sample holder in proportion to the direction for each measurement, and each measurement is stacked with 40 spines.
Curie temperature:
The powdered 0.1000g rock specimen was heated up from room temperature to 700 degrees C and cooled down in the magnetic field of 0.8 T under 10-3 Pa in vacuum. Heating and cooling rate was 150 ~ 180 degrees C /h.
Density and porosity
Three densities, i.e. dry weight in the air, wet weight in the water and the wet weight in the air were measured by a balance. There are many ways for drying the specimens, i.e. left in the room on the higher floor than the third or fourth one for a long period, or air conditioned completely for more than two months in the laboratory and in the vacuum chamber for more than 30 hours. But the heating process was not applied because we are afraid it might cause a change of the condition of NRM. Wet weight in the water was measured in the water that was purred and deioninized by an active carbon and an ion exchange resin. Wet weight in the air was measured just after the specimen was wiped off. Density and porosity can be calculated easily by these three weights. Water temperature was compensated at 3.95 degrees C.
