Paleomagnetic record and sediments flux since middle Miocene in the NE equatorial Pacific

Abstract

Deep-sea sediments in the Northeast equatorial Pacific have been gathered scientific interests as a vast reservoir of manganese nodule and rare earth elements, however their sedimentation environments through the geologic time are poorly understood. A 570 cm long sediment core was retrieved at 9°57’N and 131°42’W in 5,080 m water depth. To identify sedimentation age and periodical difference in sediments flux, paleomagnetic and rock-magnetic studies were carried out. Age constraints made by a combination of 10Be and paleomagnetic measurements. Successive AF demagnetization reveals eight times geomagnetic field reversals. In the reference geologic time scale, the eight reversal events correspond to the age of about 4.5 Ma. However, 10Be based age correction shows 13.4 Ma at 465 cm below seafloor (cmbsf). In addition, calculated sedimentation rates are changed in the range of 0.1 &#8211 2.44 mm/kyr.derstood. A 570 cm long sediment core was retrieved at 9°57’N and 131°42’W in 5,080 m water depth. To identify sedimentation age and periodical difference in sediments flux, paleomagnetic and rock-magnetic studies were carried out. Age constraints made by a combination of 10Be and paleomagnetic measurements. Successive AF demagnetization reveals eight times geomagnetic field reversals. In the reference geologic time scale, the eight reversal events correspond to the age of about 4.5 Ma. However, 10Be based age correction shows 13.4 Ma at 465 cm below seafloor (cmbsf). In addition, calculated sedimentation rates are changed in the range of 0.1 &#8211 2.44 mm/kyr.