Rock-magnetic, paleomagnetic and paleointensity data from a lava flow erupted on 4 December 2021 in La Palma (Canary Islands, Spain)

The folder “1 Rock magnetic data VFTB La Palma” contains data in .txt format of IRM acquisition curves (extension .irm), hysteresis curves (extension .hys), backfield curves (extension .coe) and thermomagnetic curves (extension .rmp) obtained on a lava flow erupted on December 4th, 2021 in La Palma (Canary Islands, Spain). Extension .rmp files including Ms-T in their file name are for magnetisation vs. temperature measurements and those including k-T in their file name are for susceptibility vs. temperature measurements. Thermomagnetic and hysteresis measurements were first performed on original specimens and then again on the same specimens after having been heated. Files including “antes” in their filename are the original measurements and those including “despues” in their file name correspond to heated samples. All measurements were performed on a Variable Field Translation Balance (VFTB) in the paleomagnetic laboratory of the University of Burgos (Spain). Columns are separated by tabs. Data can be visualised and analysed with the RockMagAnalyzer 1.0 software (Leonhardt, 2006).

The folder “2 Rock magnetic data k_fd and IRM analysis” contains four files of IRM acquisition data for the analysis of coercivity spectra (CV2-4ir0.asc, CV2-4ir7.asc, CV2-17i0.asc, CV2-17i7.asc) and one file with low- and high-frequency (470 and 4750 Hz) susceptibility data (susceptibility.asc) obtained on a lava flow erupted on December 4th, 2021, in La Palma (Canary Islands, Spain). All files have an .asc extension containing characters in ASCII format.

IRM acquisition data: (i) File CV2-4ir0.asc: progressive IRM acquisition of sample CV02-04 with remanence measurement immediately after field application. (ii) File CV2-4ir7.asc: progressive IRM acquisition of sample CV02-04 with remanence measurement 7 minutes after field application. (iii) File CV2-17i0.asc: progressive IRM acquisition of sample CV02-17 with remanence measurement immediately after field application. (iv) File CV2-17i7.asc: progressive IRM acquisition of sample CV02-17 with remanence measurement 7 minutes after field application. Column 1: measurement number; column DEMAG: first step  (100mT) is zero value after AF demagnetisation at 100 mT, following values are IRM acquisition field steps in mT; columns CD, CI, ISD, ISI, RD, RI are declination and inclination values in sample, field corrected and bedding corrected coordinates; column M: magnetic moment in emu; column J: magnetisation in emu/g; columns X, Y, Z display magnetic moment X, Y and Z coordinates. As in IRM acquisition experiments the applied field was directed towards the sample z-axis, IRM values can be obtained by dividing column Z by the sample mass value (given in g), which is found under the tag “SIZE”.  Coercivity spectra analysis has been performed with the MAX UnMix software (Maxbauer et al., 2016).

File susceptibility.asc includes data from three low-frequency (LF) and three high-frequency (HF) susceptibility measurements performed on two samples.

The folder “3 Rock magnetic data FORC” contains three files with first order reversal curves data data obtained on three samples from a lava flow erupted on December 4th, 2021, in La Palma (Canary Islands, Spain). Data can be analysed using the FORCinel software (Harrison and Feinberg, 2008).

The folder “4 Paleomagnetic data La Palma” contains two folders with paleomagnetic thermal and alternating field demagnetisation data obtained on a lava flow erupted on December 4th, 2021, in La Palma (Canary Islands, Spain). Measurements were performed with a cryogenic magnetometer in the paleomagnetic laboratory of the University of Burgos (Spain). Data are in .txt format with the extension .rs3. Columns are separated by empty spaces. In AF measurements, a value of 100 must be subtracted from all AF demagnetisation steps to obtain the real AF-step value (i.e., a demagnetisation step of 165 really means 65 mT). Data can be visualised and analysed with the Remasoft software (Chadima and Hrouda, 2006).

The folder “5 Thellier-Coe paleointensity data” contains paleointensity determination data obtained with the Thellier-Coe method on a lava flow erupted on December 4th, 2021 in La Palma (Canary Islands, Spain). Experiments were carried out at the paleomagnetic laboratory of the University of Burgos (Spain). Data are in .txt format with the extension .tdt separated by tabs. Data can be visualised and analysed with the ThellierTool software (Leonhardt et al.,2004).

The folder “6 Multispecimen paleointensity data” contains a file (CVC02_MSP_Am2.txt) with data of 3 paleointensity determinations from the Tajogaite volcano eruption on December 4th, 2021, in the island of La Palma (Canary Islands, Spain). These data were obtained with the multispecimen method (Biggin and Poidras, 2006; Dekkers and Böhnel, 2006; Fabian and Leonhardt, 2010) at the paleomagnetic laboratory of the University of Burgos (Spain). The data are in the "MSP generic format" for the online application Paleoinetnsity.org (Béguin et al., 2020), Multispecimen Protocol option. Each determination consists of five different heating steps (m0, m1, m2, m3 and m4) applied to 8 different specimens.

The folder “7 Tsunakawa-Shaw paleointensity” contains four folders with paleointensity determination data obtained with the Tsunakawa-Shaw method. The folder named “csv” contains the outcome of the best fit interpretation performed by the Jupyter notebook. The folder “d” contains the original demagnetization data obtained for each specimen. The folder “MagIC” contains the outcome compatible with MagIC software. The folder “plots” contains the outcome plots of the best fit interpretation in .pdf format. These experiments were carried out in the Paleomagnetism Laboratory at the Kochi Core Centre in Kochi University, Japan. Data can be visualised and analysed through Jupyter, using the “TS_analysis_G-cubed_r20230714_cvc02” available in the folder.

REFERENCES

Béguin, A., Paterson, G. A., Biggin, A. J., & de Groot, L. V. (2020).  Paleointensity org: an online, open source, application for the interpretation of paleointensity data. Geochemistry, Geophysics, Geosystems, 21, e2019GC008791, https://doi.org/10.1029/2019GC008791  .

Biggin, A., Poidras, T., 2006. First-order symmetry of weak-field partial thermoremanence in multi-domain ferromagnetic grains. 1. Experimental evidence and physical implications. Earth Planet. Sci. Lett. 245, 438–453. doi:10.1016/j.epsl.2006.02.035

Chadima, M. and Hrouda, F., 2006. Remasoft 3.0 a user friendly paleomagnetic data browser and analyzer. Travaux Géophysiques, XXVII, 20-21.

Dekkers, M.J., Böhnel, H.N., 2006. Reliable absolute palaeointensities independent of magnetic domain state. Earth Planet. Sci. Lett. 248, 507–516. doi:10.1016/j.epsl.2006.05.040

Fabian, K., Leonhardt, R., 2010. Multiple-specimen absolute paleointensity determination: An optimal protocol including pTRM normalization, domain-state correction, and alteration test. Earth Planet. Sci. Lett. 297, 84–94. doi:10.1016/j.epsl.2010.06.006

Harrison, R.J. and Feinberg, J.M. (2008), FORCinel: An improved algorithm for calculating first-order reversal curve distributions using locally weighted regression smoothing. Geochem. Geophys. Geosyst., 9, Q05016, doi:10.1029/2008GC001987.

Leonhardt, R., Heunemann, C. and Krása, D., 2004. Analyzing absolute paleointensity determinations: Acceptance criteria and the software ThellierTool4.0. Geochem. Geophys. Geosyst., Vol. 5, no. 12, doi.: 10.1029/2004GC000807.

Leonhardt, R., 2006. Analyzing rock magnetic measurements; The RockMagAnalyzer 1.0 software. Computers and Geosciences, 32, 1420-1431.

 Maxbauer, D.P., Feinberg, J.M., Fox, D.L., 2016. MAX UnMix: A web application for unmixing magnetic coercivity distributions. Comput. Geosci. 95, 140–145. https://doi.org/10.1016/j.cageo.2016.07.009