PSV10: A Global Data Set for 0-10 Ma Time-Averaged Field and Paleosecular Variation Studies
PSV10: A Global Data Set for 0-10 Ma Time-Averaged Field and Paleosecular Variation Studies
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DOI：
10.1002/2017gc007318
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发表时间：
2018-05-01
影响因子：
3.5
通讯作者：
Jarboe, N. A.
中科院分区：
文献类型：
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作者：
Cromwell, G.;Johnson, C. L.;Jarboe, N. A.
来自离散火山遗址的全球分布的古地磁数据以前曾被用于统计研究古分子变化和时间平均场的结构。我们提出了一种新的数据汇编PSV10，它是从过去10 Ma记录的高质量古方向中挑选出来的，包括81项研究的2,401个地点。我们要求使用现代化的实验室和加工方法，每个现场至少有四个样品，以及现场内的费舍尔精度参数，k(W)，50。确定显著构造效应或明确以过渡场状态为目标的研究被排除在外，从而减少了过渡时间间隔的过度抽样。此外，我们使用了两种方法，利用地质证据将短期序列相关性的影响降至最低。PSV10适合用于新的全球地磁和古地磁研究，因为它极大地改善了站点的空间覆盖，特别是在赤道和高纬度地区。VGP扩散是纬度相关的，当没有施加VGP截止点时，南半球的值明显高于相应的北纬地区。在整个数据集中，10度纬度槽的平均倾角异常范围在+32度到-7.52度之间，最大的负值出现在赤道和中北纬地区。新的0-5 Ma TAF模式(LN3和LN3-SC)基于PSV10的正常极性数据，表明在磁赤道附近和美洲、印度洋和亚洲高纬度径向通量增加的地区观测到了场结构的非纬向变化。
Globally distributed paleomagnetic data from discrete volcanic sites have previously been used for statistical studies of paleosecular variation and the structure of the time-averaged field. We present a new data compilation, PSV10, selected from high-quality paleodirections recorded over the past 10 Ma and comprising 2,401 sites from 81 studies. We require the use of modern laboratory and processing methods, a minimum of four samples per site, and within-site Fisher precision parameter, k(w), 50. Studies that identify significant tectonic effects or explicitly target transitional field states are excluded, thereby reducing oversampling of transitional time intervals. Additionally, we apply two approaches using geological evidence to minimize effects of short-term serial correlation. PSV10 is suitable for use in new global geomagnetic and paleomagnetic studies as it has greatly improved spatial coverage of sites, especially at equatorial and high latitudes. VGP dispersion is latitudinally dependent, with substantially higher values in the Southern Hemisphere than at corresponding northern latitudes when no VGP cutoff is imposed. Average inclination anomalies for 10 degrees latitude bins range from about +32 degrees to -7.52 degrees for the entire data set, with the largest negative values occurring at equatorial and mid-northern latitudes. New 0-5 Ma TAF models (LN3 and LN3-SC) based on selections of normal polarity data from PSV10 indicate a Non-zonal variations in field structure are observed near the magnetic equator and in regions of increased radial flux at high latitudes over the Americas, the Indian Ocean, and Asia.