Strength of the geomagnetic field in the Cretaceous Normal Superchron: New data from submarine basaltic glass of the Troodos Ophiolite
Strength of the geomagnetic field in the Cretaceous Normal Superchron: New data from submarine basaltic glass of the Troodos Ophiolite
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DOI：
10.1029/2003gc000635
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发表时间：
2004-02
期刊：
影响因子：
3.7
通讯作者：
L. Tauxe;H. Staudigel
中科院分区：
文献类型：
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作者：
L. Tauxe;H. Staudigel
在这里，我们提出了新的paleointensity数据从39个采样点收集的淬火边缘枕状熔岩和岩脉暴露在Troodos蛇绿岩（1992马），形成于白垩纪正常超时（CNS），一个大约40万年的时期，地磁场逆转非常罕见，如果在所有。蒙特卡罗模拟表明，至少有25个估计是必要的一个合理的稳健估计的平均场强。我们的数据表明，偶极子强度相当于目前的电场，或接近CNS后平均值的两倍。本文所收集的57个数据点的偶极矩的平均值和标准差（81 ± 43 ZAm 2; Z = 1021）与DSDP 522站的长期古地震强度记录所预测的结果非常吻合。CNS的新数据集表明，在停止逆转的时间段内，磁场强度很强且稳定。此外，CNS数据与当前地磁场的相似性表明，它目前处于异常的极性稳定状态。
We present here new paleointensity data from 39 sampling sites collected from the quenched margins of pillow lavas and dikes exposed within the Troodos Ophiolite (∼92 Ma), formed during the Cretaceous Normal Superchron (CNS), a period of approximately 40 million years when the geomagnetic field reversed extremely infrequently if at all. Monte Carlo simulations suggest that a minimum of 25 estimates are necessary for a reasonably robust estimate for the average field strength. Our data suggest a dipole strength equivalent to the present field or nearly twice the post‐CNS average. The mean and standard deviation of the dipole moment (81 ± 43 ZAm2; Z = 1021) from the 57 data points compiled here agree remarkably well with those predicted from the long paleointensity record derived from DSDP Site 522. The new data set for the CNS suggests a picture of a strong and stable field during the period of time when it stopped reversing. Moreover, the similarity of the CNS data with the present geomagnetic field suggests that it is presently in a state of unusual polarity stability.