2026-09-09T12:00:28Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/112712026-01-23T01:05:43Zcom_10259.4_2560com_10259_5086com_10259_2604col_10259.4_2561

Calvo Rathert, Manuel Sánchez Moreno, Elisa María Herrero-Bervera, Emilio Vashakidze, George T. Morales, Juan Ignacio . Goguitchaichvili, Avto Solé, Jesús Pérez-Rodríguez, Nayeli Kavsadze, Manana 2026-01-22T13:17:13Z 2026-01-22T13:17:13Z 2026 1880-5981 https://hdl.handle.net/10259/11271 10.1186/s40623-025-02333-3 1880-5981 A paleomagnetic and paleointensity study has been performed on 28 basaltic flows from a sequence in the Lesser Caucasus. Two radiometric determinations yielded 3.45 ± 0.23 Ma in its lower and 3.43 ± 0.19 Ma in its upper part. Paleomagnetic determinations in the lower section (14 flows) yielded an anomalous direction D = 252.8°, I = 43.1°, (α95 = 3.7°), reflecting a transitional record. In the upper section (14 flows), a reverse polarity direction D = 185.8°, I = − 53.1°, (α95 = 2.3°) was obtained. Analysis of the scatter in paleomagnetic directions suggests that the stable anomalous direction observed throughout the lower section might have persisted for several centuries. Thellier–Coe paleointensity experiments on 165 specimens produced only 7 successful determinations. Very low paleointensity values below 10 μT were obtained in the lower, and stronger ones (35 and 50 μT) in the upper flows. Application of a pTRM-check correction to the data resulted in an important increase of successful determinations (78) and a significant intra- and inter-flow coherence of results, confirming very low paleointensities in the lower section and stronger ones in the upper flows. 20 paleointensity determinations with the multispecimen method produced results in 16 samples (13 flows). A multimethod analysis combining results of both methods yielded paleointensities between 5.4 and 12.5 μT in the lower flows, reflecting a transitional field. The upper flows produced a mean paleointensity B = 40.9 ± 9.4 μT. The sequence seems to record the C2An.3n–C2An.3r (Gauss–Mammoth) reversal at 3.330 Ma. Work funded by project PID2024-159094NB-I00 (Spanish Agencia Estatal de Investigación AEI/10.13039/501100011033 and ERDF), project BU037P23 (Junta de Castilla y León and the European Research and Development Fund), and the Shota Rustaveli National Science Foundation of Georgia (SRNSFG) (Grant No. FR-22–19681—Volcanic facies architecture of lava flows and associated interflow horizons from Javakheti Volcanic Province– South Georgia). application/pdf eng Springer Earth Planets Space. 2026, V. 78, n. 1, 10 https://doi.org/10.1186/s40623-025-02333-3 Atribución 4.0 Internacional http://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess Paleomagnetism Paleointensity Rock-magnetism Polarity transition Caucasus Paleomagnetism Geofísica Geología histórica Paleomagnetismo Geophysics Historical geology Paleomagnetism A record of a stable transitional VGP in a Pliocene lava flow sequence from the Lesser Caucasus info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Earth, Planets and Space 78 1