论文部分内容阅读
详细的古地磁及岩石磁学研究表明磁铁矿和赤铁矿是宝鸡古土壤层S7和黄土层L8的特征剩磁的主要载磁矿物,在稳定的正反极性期间,这两种磁性矿物携带的剩磁方向完全一致。然而,在地磁漂移事件或者松山-布容(M-B)极性转换的过程中,这两种载磁矿物有时携带的剩磁方向不同。高分辨率的磁性地层结果证实宝鸡古土壤层S7和黄土层L8能记录300~500年的短期地球磁场极性倒转事件。经与日本大阪湾高分辨率的海洋沉积物中记录的同期短期极性倒转事件相比,估算宝鸡剖面土壤层S7和黄土层L8的天然剩磁锁定深度小于5~8cm。
Detailed paleomagnetic and rock magnetism studies show that magnetite and hematite are the major magnetites of the characteristic remanence of the ancient soil layer S7 and the loess L8 in Baoji. During the stable positive and negative polarities, the two magnetic Remaining magnetic minerals carry the direction of the same. However, during the geomagnetic drift event or Matsunaga-Matsubara (M-B) polarity transition, the two magnetospheric minerals sometimes carry residual magnetization in different directions. The high-resolution magnetic stratum results confirm that the Baoji paleosol layer S7 and the loess layer L8 can record short-term earth magnetic field polarity reversal events of 300-500 years. Comparing with the short-term polarity reversal events recorded in high-resolution marine sediment of Osaka Bay, Japan, the natural remanence locking depth of soil layer S7 and loess layer L8 in Baoji section is less than 5 ~ 8cm.