Magnetic reversal history of Pleistocene sediments at Old Crow, northwestern Yukon Territory
Magnetic reversal history of Pleistocene sediments at Old Crow, northwestern Yukon Territory
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育空地区西北部老克劳更新世沉积物的磁反转历史
DOI：
10.1139/e82-077
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发表时间：
1982
影响因子：
1.4
通讯作者：
S. Robertson
中科院分区：
文献类型：
--
作者：
G. W. Pearce;J. Westgate;S. Robertson
位于北方育空地区未受冰川影响的部分，靠近老乌鸦的豪猪河河岸由约55 m的河流和湖泊砾石、砂、粉砂和粘土层间组成。 对这一序列进行了近距离采样，以进行古地磁分析，发现沉积物具有天然反磁化（NRM），其方向稳定，平均破坏性磁场为200-300 Oe（16-24 kA/m）。 因此，良好的古地磁数据，可以从沉积物已受到永久冻土条件下，虽然有些样品显示干扰的NRM方向的cryoturbation.Magnetic极性转换集中在17和26米以上的河流的水平和15个样品之间定义了一个相当长的时间间隔的反极性。 NRM在过渡期间的行为是复杂的，其180°的突然转换，但在相当长的时间内，倾角显示出非常不稳定的变化。这可能是由于混合在单一样品的C...
The banks of the Porcupine River near Old Crow in the unglaciated part of the northern Yukon consist of about 55 m of interbedded fluvial and lacustrine gravels, sands, silts, and clays. This sequence was sampled closely for palaeomagnetic analysis and the sediments were found to possess a natural remanent magnetization (NRM) that is stable in direction with mean destructive fields of 200–300 Oe (16–24 kA/m). Therefore, good palaeomagnetic data can be obtained from sediments that have been subjected to permafrost conditions, although some samples show disturbance of NRM directions by cryoturbation.Magnetic polarity transitions are centred at 17 and 26 m above river level and the 15 samples between them define an interval of reversed polarity of considerable duration. The behaviour of NRM during the transition periods is complex with declination switching abruptly by 180° but with the inclination displaying very erratic variation over a considerable time. This may be caused by mixing in single samples of c...