Rock-magnetic, paleomagnetic and multimethod paleointensity data from an upper Miocene lava flow sequence from São Vicente (Cape Verde)

Resumen

The folder “Praia Grande Paleomagnetism Data.zip” contains paleomagnetic thermal and alternating field demagnetisation data obtained on upper Miocene volcanic rocks from São Vicente (Cape Verde). Measurements were performed 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. Data can be visualised and analysed with the Remasoft software (Chadima and Hrouda, 2006). The folder “Praia Grande rock magnetism Data.zip” contains data in .txt format of IRM acquisition curves (extension .irm), hysteresis curves (extension .hys), backfield curves (extension .coe) and thermomagnetic magnetisation versus temperature curves (extension .rmp) obtained on upper Miocene volcanic rocks from São Vicente (Cape Verde). Measurements were performed 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 “Praia Grande Thellier-Coe Data.zip”contains paleointensity determination data obtained with the Thellier-Coe method on upper Miocene volcanic rocks from São Vicente (Cape Verde). Measurements were performed in 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 “Praia Grande Multispecimen.zip” contains paleointensity determination data on upper Miocene volcanic rocks from São Vicente (Cape Verde) obtained with the multispecimen method (Biggin and Poidras, 2006; Dekkers and Böhnel, 2006; Fabian and Leonhardt, 2010) at Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Geofísica, Unidad Michoacán, UNAM, Mexico. Two kinds of files can be found: Five .txt files (M0.txt, M1.txt, M2.txt, M3.txt, M4.txt) and five .jr6 files (M0.jr6, M1.jr6, M2.jr6, M3.jr6, M4.jr6). Both types of files are in .txt format. The .txt files directly provide the measurement data generated during the multispecimen experiments. The first columns of the .jr6 files display the following information: column 1: specimen name; column 2: experimental step (explanation below); columns 3, 4 and 5: three magnetisation components M(x), M(y) and M(z); column 6: exponent of the magnetisation components to obtain the magnetisation value in A/m. In the multispecimen experiments, the specimen-name (e.g. PRG1-3) can be divided in two parts, the first three characters indicate the sample (flow), the last character the specimen number (1 to 7). Eight different experimental steps (column 2) can be distinguished: NRM, A10, A20, A30, A40, A50, A60 and A70. They correspond to the measurement of the NRM and of steps in which fields of 10, 20, 30, 40, 50, 60 and 70 mT where respectively applied. Files M0 (.txt and .jr6) include only NRM measurements, files M1 include measurements of specimens heated with an applied field parallel to their NRM, files M2 include measurements of specimens heated with an applied field antiparallel to their NRM, files M3 include measurements of specimens heated in zero field and cooled down in an applied field parallel to their NRM, and files M4 include again include measurements of specimens heated with an applied field parallel to their NRM. <strong>REFERENCES</strong> 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. <em>Travaux Géophysiques</em>, 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 Leonhardt, R., 2006. Analyzing rock magnetic measurements; The RockMagAnalyzer 1.0 software.<em>Computers and Geosciences</em>, 32, 1420-1431. Leonhardt, R., Heunemann, C. and Krása, D., 2004. Analyzing absolute paleointensity determinations: Acceptance criteria and the software ThellierTool4.0. <em>Geochem. Geophys. Geosyst.</em>, Vol. 5, no. 12, doi.: 10.1029/2004GC000807. Monster, M.W.L., de Groot, L. V., Dekkers, M.J., 2015. MSP-Tool: A VBA-Based Software Tool for the Analysis of Multispecimen Paleointensity Data. Front. Earth Sci. 3, 1–9. https://doi.org/10.3389/feart.2015.00086