Study of Declination, Inclination and Absolute Paleointensity of the Short-Term Geomagnetic Behavior (i.e. Cryptochron C2r.2r-1, ca. 2.46 #177;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.