RT info:eu-repo/semantics/article
T1 An Integrated Paleomagnetic, Multimethod- Paleointensity, and Radiometric Study on Cretaceous and Paleogene Lavas From the Lesser Caucasus: Geomagnetic and Tectonic Implications
A1 Calvo Rathert, Manuel
A1 Bógalo Román, Mª Felicidad
A1 Morales, J.
A1 Goguitchaichvili, Avto
A1 Lebedev, Vladimir A.
A1 Vashakidze, George T.
A1 García Redondo, Natalia
A1 Herrero, E.
K1 Caucasus
K1 Cretaceous
K1 K-Ar dating
K1 Paleointensity
K1 Paleomagnetism
K1 Rock magnetism
K1 Magnetismo
K1 Magnetism
K1 Geología
K1 Geology
K1 Física
K1 Physics
AB Sixteen rhyolitic and dacitic Cretaceous and Paleocene-Eocene lavas from the Lesser Caucasus have been subjected to paleomagnetic and multimethod paleointensity experiments to analyze the variations of the Earth's magnetic field. Paleointensity experiments were performed with two methods. Thellier-type experiments with the IZZI method on 65 specimens (nine flows) yielded 15 successful determinations and experiments with the multispecimen method on 14 samples (seven flows) yielded two successful determinations. The joint analysis of the results obtained with both methods produced a mean FuK = (19.9 ± 3.7) µT for upper Cretaceous and FPg = (20.7 ± 3.3) µT for Paleogene sites. Low virtual axial dipole moments for the Cretaceous (3.4 × 1022 Am2) and Paleogene (3.5 × 1022 Am2) samples support the idea of a lower average dipole moment during periods of stable polarity of the Earth magnetic field. Mean flow paleomagnetic directions did not match expected upper Cretaceous to Paleogene directions calculated from the European Apparent Polar Wander Path. While inclination results roughly agreed with expected values, a group of sites showed nearly North-South paleodeclinations (D = 1.1° ± 14.2°), and another group displayed eastward deviated paleodeclinations (D = 72.9° ± 26.6°). These results suggest the occurrence of nearly vertical-axis rotations, probably as a result of continental collision since Oligocene. In addition to paleomagnetic and palaeointensity analyses, new K-Ar absolute age determinations have been performed on three of the studied sites, yielding Late Cretaceous ages (78.7 ± 1.7, 79.7 ± 1.6, and 83.4 ± 1.8 Ma (2σ)).
PB American Geophysical Union (AGU)
SN 2169-9313
YR 2021
FD 2021-02
LK http://hdl.handle.net/10259/6117
UL http://hdl.handle.net/10259/6117
LA eng
NO Project PID2019-105796GB-100/AEI/10.13039/501100011033 (Agencia Estatal de Investigación, Spain). M. Calvo-Rathert acknowledges funding from the Fulbright Commission and the Spanish Ministry of Science, Innovation, and Universities for a research stay at Hawaii University at Manoa. A. Goguitchaichvili acknowledges financial support from UNAM-PAPIIT no. IN101920. N. García-Redondo acknowledges financial support from Junta de Castilla y León and the European Research Development Fund (ERDF). EHB acknowledges financial support for laboratory maintenance and measurements to SOEST-HIGP and National Science Foundation grants. These is SOEST 11143 and HIGP 2420 contribution.
DS Repositorio Institucional de la Universidad de Burgos
RD 24-abr-2024