Low-temperature magnetic properties of andesitic rocks from Popocatepetl stratovolcano, Mexico
Por:
Kosterov A., Conte G., Goguitchaichvili A., Urrutia-Fucugauchi J.
Publicada:
1 ene 2009
Resumen:
To contribute to the growing database of magnetic properties of rocks and minerals at cryogenic temperatures, we have measured magnetization, low-field susceptibility, and hysteresis loops as a function of temperature between 2 K (10 K for hysteresis) and 300 K for twelve representative Samples from a Suite of volcanic rocks of predominantly andesitic composition erupted by the Popocatepetl stratovolcano, Mexico. High temperature susceptibility measurements have yielded Curie points (T(C)) mostly between 430 and 550 degrees C, two samples additionally containing a magnetic phase with T(C) of 300-320 degrees C, and one sample-with 140-170 degrees C. Hysteresis measurements at room temperature have revealed invariably the presence of a low-coercivity mineral with coercive force ranging from 10 to 20 mT. This Suggests that NRM of Popocatepetl rocks is carried by an intermediate titanomagnetite of composition between approximately TM04 and TM20. Thermal demagnetization of SIRM given at 2 K
Filiaciones:
Kosterov A.:
Center for Advanced Marine Core Research, Kochi University, B200 Monobe, Nankoku, Kochi 783-8502, Japan
Conte G.:
Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City 04510, DF, Mexico
Goguitchaichvili A.:
Univ Nacl Autonoma Mexico, Lab Interinst Magnetismo Nat, Inst Geofis, Morelia 58098, Michoacan, Mexico
Urrutia-Fucugauchi J.:
Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City 04510, DF, Mexico
Hybrid Gold
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