Directions of the low-T and high-T components an the difference of the declination of ODP Site 124-770B (Table 1)

Experiments with thermal demagnetization of the samples from Site 770 of Ocean Drilling Leg 124 indicate that the samples have two magnetic components. An assumption that the low-temperature component, which is removed between 100°C and 200°C, is the secondary magnetization acquired in Brunhes normal chron, gives a core orientation. The oriented high-temperature component directions were tightly clustered around a pair of antipodal directions. The change of declination of the high-temperature component shows that the Celebes Sea was rotated counterclockwise about 60° during Eocene and Oligocene time.

对大洋钻探第124航次770站位的样品开展热退磁（thermal demagnetization）实验，结果显示样品存在两类磁组分（magnetic components）。研究提出假设：在100℃至200℃区间内被移除的低温磁组分（low-temperature component），为布容正向极性时（Brunhes normal chron）形成的次生磁化（secondary magnetization），该假设可用于岩心定向（core orientation）。经定向处理的高温磁组分（high-temperature component）方向紧密聚集于一对反极方向（antipodal directions）周围。高温磁组分的磁偏角（declination）变化表明，西里伯斯海（Celebes Sea）在始新世与渐新世时期发生了约60°的逆时针旋转。