Natural Science Laboratory, Toyo University
Mejiro Gakuen High School
School of Earth Sciences, IHS, Kyoto University
National Institute of Polar Research
抄録(英)
Secondary magnetization produced during a thermal experiment in Thelliers' method was studied on 12 samples from the Mt. Riiser-Larsen area for that paleomagnetic data already been reported (N. ISHIKAWA and M. FUNAKI: Proc. NIPR Symp. Antarct. Geosci., 10, 79, 1997), and considered suitable for paleomagnetic study from the rock magnetic characteristics of samples. A remeasurement test of NRM on the same temperature step (NRM-check) as well as PTRM (PTRM-check) in air and in vacuum revealed secondary magnetization concerned with NRM and TRM which appeared at the same temperature, around 350℃, that would be explained by the oxidation of sulfide observed under a microscope. Secondary magnetization around 550℃ which appeared in air might also be caused by magneto-mineralogical change. These results are supported by the large variation of initial susceptibility around 300℃ and 550℃. Both the secondary magnetization of NRM and that of PTRM produced in vacuum were comparable to in air.