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To be able to test and calibrate the calculation of paleointensity data across multiple platforms and software bases, we have provided a data set of 20 paleointensity specimens with which users can test their software. The data set can be downloaded here.
The 20 specimens used for testing and calibration are drawn from the compilation of data from historical location compiled by Paterson et al. (2013). The data are from 12 studies and represent 15 localities or laboratory experiments (16 unique heating events). The methods and materials used are outlined in Table 1. The data from Selkin et al. (2000) and Shaar et al. (2010) are corrected for the effects of non-linear TRM and/or anisotropy. The non-linear TRM coefficients (i.e., $$A_1$$ and $$A_2$$) as well as the six unique elements required to construct the anisotropy tensors (i.e., $$s_{j=1\dots6}$$) are available as text files to download here.
| Sample name | Reference | Location | pTRM checks | pTRM tail checks | Additivity checks | Method | Material | Comment |
| 187A | Biggin et al. (2007) | Mt. Etna, 1979 | Yes | Yes | No | MW Coe | Basaltic lava | With AF cleaning |
| 283A | Biggin et al. (2007) | Mt. Etna, 1950 | Yes | Yes | No | MW Coe | Basaltic lava | |
| A-3-3 | Yamamoto et al. (2003) | Hawaii, 1960 | Yes | No | No | Coe | Basaltic lava | |
| AL2770-3b | Bowles et al. (2006) | East Pacific Rise, 1991/92 | Yes | No | No | Coe | SBG | |
| BR06-4F | Donadini et al. (2007) | Helsinki, 1906 | Yes | Yes | No | Coe | Brick | |
| C-4-4L | Yamamoto et al. (2003) | Hawaii, 1960 | Yes | No | No | Coe | Basaltic lava | With low temperature demagnetization |
| HEL2-2d | Donadini et al. (2007) | Helsinki, 1906 | Yes | Yes | No | Coe | Brick | |
| KF-3-1 | Tanaka et al. (2012) | Krafla, 1984 | Yes | No | No | Coe | Basaltic lava | |
| LV6C3A | Paterson et al. (2010b) | Láscar, 1993 | Yes | Yes | No | Coe | Andesitic clast | |
| m428b1 | Selkin et al. (2000) | Stillwater Complex | Yes | No | No | Coe | Anorthosite | Anisotropic TRM corrected |
| MCT | Muxworthy (1998) | N/A | No | Yes | No | Coe | Synthetic magnetite | Average grain size 22.5 μm |
| MSH6E13 | Paterson et al. (2010b) | Mt. St. Helens, 1980 | Yes | Yes | Yes | Coe | Dacitic clast | |
| P1MY | Muxworthy et al. (2011) | Parícutin, 1943 | Yes | Yes | No | Coe | Basaltic lava | |
| RD2358-4f | Pick and Tauxe (1993) | East Pacific Rise, 1990 | Yes | Yes | No | Coe | SBG | |
| RS25b | Shaar et al. (2010) | N/A | Yes | No | No | IZZI | Remelted copper slag | Anisotropic and non-linear TRM corrected |
| RS26a | Shaar et al. (2010) | N/A | Yes | No | No | IZZI | Remelted copper slag | Anisotropic and non-linear TRM corrected |
| RS26e | Shaar et al. (2010) | N/A | Yes | No | No | IZZI | Remelted copper slag | Anisotropic and non-linear TRM corrected |
| TS01-20A-2 | Yamamoto and Hoshi (2008) | Sakurajima, 1914 | Yes | Yes | No | Coe | Andesitic lava | |
| VM1F | Muxworthy et al. (2011) | Vesuvius, 1940 | Yes | Yes | No | Coe | Basaltic lava | |
| W3 | Krása et al. (2003) | N/A | Yes | Yes | Yes | Coe | Synthetic magnetite | Average grain size 0.5 μm |
A complete table of the standard paleointensity statistics and the details of the chosen best-fits for the above 20 specimens is available for download here. For the calculation of statistics that make a comparison with a known reference direction (e.g., $$\alpha'$$, or $$CRM(\%)$$) an arbitrary reference direction is used. This direction is Dec. = 90°, Inc = 45°, or $$\left[0, \frac{1}{\sqrt{2}}, \frac{1}{\sqrt{2}}\right]$$ in Cartesian coordinates. For the calculation of $$SCAT$$, $$\beta_{threshold}$$ is taken to be 0.1.
The paleointensity estimates along with the average, standard deviation and scatter for the 20 specimens are given in Table 2. This table is also available for download as an Excel spreadsheet here.
| Sample name | BExp (μT) | BAnc (μT) |
| 187A | 44.1 | 45.2 |
| 283A | 43.3 | 116.3 |
| A-3-3 | 36.2 | 35.6 |
| AL2770-3b | 35.8 | 26.0 |
| BR06-4F | 49.6 | 41.9 |
| C-4-4L | 36.2 | 36.1 |
| HEL2-2d | 49.6 | 49.5 |
| KF-3-1 | 52.1 | 44.1 |
| LV6C3A | 24.0 | 23.4 |
| m428b1 | 25.0 | 25.1 |
| MCT | 55.6 | 71.7 |
| MSH6E13 | 55.6 | 22.1 |
| P1MY | 45.0 | 30.1 |
| RD2358-4f | 37.0 | 85.7 |
| RS25b | 30.0 | 29.3 |
| RS26a | 60.0 | 63.3 |
| RS26e | 60.0 | 58.1 |
| TS01-20A-2 | 45.7 | 50.1 |
| VM1F | 44.0 | 74.0 |
| W3 | 60.0 | 60.7 |
| N | 20 | |
| m (μT) | 49.4 | |
| s (μT) | 24.2 | |
| δB(%) | 48.9 | |
| δBN(%) | 66.3 |
An example of the calculation of weighted average and standard deviation of the above described data set is given in the Excel spreadsheet available for download here. In this example, the weights are taken to be $$\frac{1}{\left(\sigma_B\right)^2}$$.
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