Study of Declination, Inclination and Absolute Paleointensity of the Short-Term Geomagnetic Behavior (i.e. Cryptochron C2r.2r-1, ca. 2.46 ± 0.13 Ma) Recorded at the Type Section of Halawa Valley, Koo’lau Volcano, Oahu, Hawaii, USA

摘要

A novel determination of the absolute paleointensity (P.I) of 28 flows that recorded Cryptochron C2r.2r-1 (ca. 2.46 ± 0.13 Ma) using the modified Thellier-Coe method was undertaken to understand the geomagnetic evolution of the paleofield during an excursion with the existence of less than 10 Kyrs. The successful PI determinations along the 120-meter sequential erupted flows indicate that within the truly transitional/excursional portion of the record there is a conspicuous decrease of the PI values ranging from 20 μT to low values of about 5 μT. These values are comparable to lows similar to polarity transitions of the geomagnetic field. At the base of the sequence , the record shows oscillations of the paleofied ranging from 120 μT and as low as ~10 μT with very variable changes of the non-transitional/excursional paleofield.