Remanence magnetic records of the recent 130 000 years from the sediments in Nansha area, South China Sea

Abstract

Two hundred and eighty-one samples, collected from drilling core NS93-5 located in the Nansha area of the South China Sea, were used to study the magnetic characteristics of the sediments in the sea. Detailed rock magnetic results show that the magnetic minerals of the sediments were dominated by ferrimagnetic minerals such as magnetite, and a small contribution of hematite and maghematite also existed. The sediments recorded three negative values of remanence magnetic inclination at the depth: 191 206 cm, 232 248 cm, and 292 308 cm. The corresponding ages of these negative values were 65.87 68.7 ka B.P., 73.4 80.8 ka B.P. and 108.4 113.6 ka B.P., respectively, according to stratigraphy of oxygen isotope, ¹⁴C, and the age of a volcanic ash layer. The negative value during 108.4 113.6 ka B.P. may be the record of a Blake event in the sediments of the Nansha area.