2007 年 2007 巻 27 号 p. 219-226
At Gerede Ardicli trench site on the North Anatolian Fault System (NAFS), ages of sedimentary beds cut by fault were estimated by archaeomagnetic method. The beds exposed on the trench walls were deposited under marsh conditions after 6th centuries (Okumura et al.,2003). The discrete samples were collected from 16 horizons analyzed after alternating field (AF) demagnetization for three components (declination, inclination, and intensity of remanent magnetization). As no geomagnetic secular variation data for archaeomagnetism was available in Turkey, the results were compared with those obtained in Bulgaria. C-14 ages (Okumura at al.,2002) and an archaeomagnetic age of the brick (Kanai at al.,2005) were used as the reference data to constrain the age ranges. Data for declination and normalized remanent magnetic intensities for seven horizons corresponds well to the Bulgarian data. Thus, age estimation based on archaeomagnetic study will provide us effective age constraint of paleoearthquakes.
