Reliability of palaeomagnetic poles from sedimentary rocks
文献类型：期刊论文
| 作者 | Vaes, Bram3; Li, Shihu1,2; Langereis, Cor G.3; van Hinsbergen, Douwe J. J.3 |
| 刊名 | GEOPHYSICAL JOURNAL INTERNATIONAL
 |
| 出版日期 | 2021-05-01 |
| 卷号 | 225期号:2页码:1281-1303 |
| 关键词 | Palaeomagnetic secular variation Palaeomagnetism Statistical methods Inclination shallowing E/I correction |
| ISSN号 | 0956-540X |
| DOI | 10.1093/gji/ggab016 |
| 英文摘要 | Palaeomagnetic poles form the building blocks of apparent polar wander paths and are used as primary input for quantitative palaeogeographic reconstructions. The calculation of such poles requires that the short-term, palaeosecular variation (PSV) of the geomagnetic field is adequately sampled and averaged by a palaeomagnetic data set. Assessing to what extent PSV is recorded is relatively straightforward for rocks that are known to provide spot readings of the geomagnetic field, such as lavas. But it is unknown whether and when palaeomagnetic directions derived from sedimentary rocks represent spot readings of the geomagnetic field and sediments arc moreover suffering from inclination shallowing, making it challenging to assess the reliability of poles derived from these rocks. Here, we explore whether a widely used technique to correct for inclination shallowing, known as the elongation-inclination (E/I) method, allows us to formulate a set of quality criteria for (inclination shallowingcorrected) palaeomagnetic poles from sedimentary rocks. The E/I method explicitly assumes that a sediment-derived data set provides, besides flattening, an accurate representation of PSV. We evaluate the effect of perceived pitfalls for this assumption using a recently published data set of 1275 individual palaeomagnetic directions of a >3-km-thick succession of similar to 69-41.5 Ma red beds from the Gonjo Basin (eastern Tibet), as well as synthetic data generated with the TK03.GAD field model. The inclinations derived from the uncorrected data set are significantly lower than previous estimates for the basin, obtained using coeval lavas, by correcting inclination shallowing using anisotropy-based techniques, and by predictions from tectonic reconstructions. We find that the E/I correction successfully restores the inclination to values predicted by these independent data sets if the following conditions arc met: the number of directions N is at least 100, the A95 cone of confidence falls within a previously defined A95(min-max) reliability envelope, no negative reversal test is obtained and vertical-axis rotation differences within the data set do not exceed 15 degrees. We propose a classification of three levels (A, B and C) that should be applied after commonly applied quality criteria for palaeomagnetic poles are met. For poles with classification 'A', we find no reasons to assume insufficient quality for tectonic interpretation. Poles with classification 'B' could be useful, but have to be carefully assessed, and poles with classification 'C' provide unreliable palaeolatitudes. We show that application of these criteria for data sets of other sedimentary rock types classifies data sets whose reliability is independently confirmed as 'A' or 'B', and that demonstrably unreliable data sets are classified as 'C', confirming that our criteria are useful, and conservative. The implication of our analysis is that sediment-based data sets of quality 'A' may be considered statistically equivalent to data sets of site-mean directions from rapidly cooled igneous rocks like lavas and provide high-quality palaeomagnetic poles. |
| WOS关键词 | APPARENT POLAR WANDER ; GEOMAGNETIC SECULAR VARIATION ; RED-BEDS ; MAGNETO-BIOSTRATIGRAPHY ; PALAEOSECULAR VARIATION ; REMANENT MAGNETIZATION ; LATITUDE DEPENDENCE ; EASTERN TIBET ; GONJO BASIN ; INCLINATION |
| 资助项目 | Netherlands Organisation for Scientific Research (NWO)[865.17.001] ; Royal Society-K. C. Wong International Fellowship[NF 170033] |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000646866900035 |
| 出版者 | OXFORD UNIV PRESS |
| 资助机构 | Netherlands Organisation for Scientific Research (NWO) ; Netherlands Organisation for Scientific Research (NWO) ; Netherlands Organisation for Scientific Research (NWO) ; Netherlands Organisation for Scientific Research (NWO) ; Royal Society-K. C. Wong International Fellowship ; Royal Society-K. C. Wong International Fellowship ; Royal Society-K. C. Wong International Fellowship ; Royal Society-K. C. Wong International Fellowship ; Netherlands Organisation for Scientific Research (NWO) ; Netherlands Organisation for Scientific Research (NWO) ; Netherlands Organisation for Scientific Research (NWO) ; Netherlands Organisation for Scientific Research (NWO) ; Royal Society-K. C. Wong International Fellowship ; Royal Society-K. C. Wong International Fellowship ; Royal Society-K. C. Wong International Fellowship ; Royal Society-K. C. Wong International Fellowship ; Netherlands Organisation for Scientific Research (NWO) ; Netherlands Organisation for Scientific Research (NWO) ; Netherlands Organisation for Scientific Research (NWO) ; Netherlands Organisation for Scientific Research (NWO) ; Royal Society-K. C. Wong International Fellowship ; Royal Society-K. C. Wong International Fellowship ; Royal Society-K. C. Wong International Fellowship ; Royal Society-K. C. Wong International Fellowship ; Netherlands Organisation for Scientific Research (NWO) ; Netherlands Organisation for Scientific Research (NWO) ; Netherlands Organisation for Scientific Research (NWO) ; Netherlands Organisation for Scientific Research (NWO) ; Royal Society-K. C. Wong International Fellowship ; Royal Society-K. C. Wong International Fellowship ; Royal Society-K. C. Wong International Fellowship ; Royal Society-K. C. Wong International Fellowship |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/101239]  |
| 专题 | 地质与地球物理研究所_岩石圈演化国家重点实验室 |
| 通讯作者 | Li, Shihu |
| 作者单位 | 1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 2.Univ Lancaster, Lancaster Environm Ctr, Lancaster LA1 4YQ, England 3.Univ Utrecht, Dept Earth Sci, NL-3584 CS Utrecht, Netherlands |
| 推荐引用方式 GB/T 7714 | Vaes, Bram,Li, Shihu,Langereis, Cor G.,et al. Reliability of palaeomagnetic poles from sedimentary rocks[J]. GEOPHYSICAL JOURNAL INTERNATIONAL,2021,225(2):1281-1303. |
| APA | Vaes, Bram,Li, Shihu,Langereis, Cor G.,&van Hinsbergen, Douwe J. J..(2021).Reliability of palaeomagnetic poles from sedimentary rocks.GEOPHYSICAL JOURNAL INTERNATIONAL,225(2),1281-1303. |
| MLA | Vaes, Bram,et al."Reliability of palaeomagnetic poles from sedimentary rocks".GEOPHYSICAL JOURNAL INTERNATIONAL 225.2(2021):1281-1303. |
入库方式： OAI收割
来源：地质与地球物理研究所
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