RT info:eu-repo/semantics/article
T1 Reliability of the palaeomagnetic signal recorded in a lava flow erupted on 4 December 2021 in La Palma (Canary Islands, Spain)
A1 Calvo Rathert, Manuel
A1 Vernet Tarrago, Eva
A1 Parés Casanova, Josep M.
A1 Soler, Vicente
A1 Sánchez Moreno, Elisa María
A1 Bógalo Román, Mª Felicidad
A1 Carrancho Alonso, Ángel
A1 Yamamoto, Yuhji
A1 Rodríguez Méndez, Lidia
K1 Palaeointensity
K1 Rock and mineral magnetism
K1 Palaeomagnetism
K1 Oceanic hotspots and intraplate volcanism
K1 Paleomagnetismo
K1 Paleomagnetism
K1 Paleontología
K1 Paleontology
K1 Magnetismo
K1 Magnetism
K1 Arqueología
K1 Archaeology
AB A basaltic lava flow erupted from the Tajogaite volcano on 4 December 2021, in La Palma (Canary Islands, Spain) was sampled to find out to what extent reliable and correct information on both intensity and direction of the Earth's magnetic field can be obtained from the palaeomagnetic signal recorded in a lava flow which erupted under known conditions. Samples were taken every few centimetres across a flow up to a total of 27 oriented cores. Palaeomagnetic experiments showed a strong viscous overprint in many samples. Nevertheless, the mean palaeomagnetic direction obtained agrees well with the actual value from IGRF-13. Rock magnetic experiments were performed to obtain additional information about the quality and reliability of the results and the reasons for unsuccessful determinations. Analysis of mostly irreversible thermomagnetic curves showed that the carriers of remanence were magnetite and titanomagnetite of low and/or intermediate Curie-temperature. Hysteresis parameter ratios showed a pronounced variability across the flow. Analyses of frequency dependent susceptibility, IRM acquisition coercivity spectra and FORCs showed a noticeably presence of very low coercivity grains (multidomain and superparamagnetic-single domain boundary). Multimethod palaeointensity experiments were performed with the Thellier-Coe, multispecimen and Tsunakawa-Shaw methods. Only three of 25 cores from the flow yielded successful Thellier-Coe determinations, in agreement with the expected field value of 38.7 μT (IGRF-13). However, palaeointensities of 60 per cent of the specimens agree with the expected value performing an informal analysis without considering criteria thresholds. Four of six Tsunakawa-Shaw determinations performed on samples from the flow yielded correct results, but three multispecimen determinations providing apparently successful determinations largely underestimate the expected field intensity. Combination of three Thellier-Coe and four Tsunakawa-Shaw successful determinations yields a multimethod palaeointensity result B = (36.9 ± 2.0) μT in good agreement with the expected field intensity.
PB Oxford University Press
SN 0956-540X
YR 2024
FD 2024
LK http://hdl.handle.net/10259/10167
UL http://hdl.handle.net/10259/10167
LA eng
NO This work was funded by project PID2019-105796GB-100/AEI/10.13039/501100011033 (Spanish Agencia Estatal de Investigación), project BU037P23 (Junta de Castilla y León and the European Research and Development Fund, ERDF) and JSPS KAKENHI Grant No. 21H01171. We thank Antonio González (Cabildo de La Palma) for his invaluable support and help during our visit to the island of La Palma. We also wish to thank Dr Eugenio Fraile Nuez (IEO-CSIC) for providing us the submarine lava flow samples. We also wish two thank two anonymous reviewers for helpful comments.
DS Repositorio Institucional de la Universidad de Burgos
RD 15-mar-2025