Artículos PALEOMAG-UBUhttp://hdl.handle.net/10259.4/25612024-03-28T11:24:12Z2024-03-28T11:24:12ZRock Magnetism of Lapilli and Lava Flows from Cumbre Vieja Volcano, 2021 Eruption (La Palma, Canary Islands): Initial ReportsParés Casanova, Josep M.Vernet Tarrago, EvaCalvo Rathert, ManuelSoler, VicenteBógalo Román, Mª FelicidadÁlvaro, Anahttp://hdl.handle.net/10259/75972023-04-20T09:26:42Z2022-07-01T00:00:00ZRock Magnetism of Lapilli and Lava Flows from Cumbre Vieja Volcano, 2021 Eruption (La Palma, Canary Islands): Initial Reports
Parés Casanova, Josep M.; Vernet Tarrago, Eva; Calvo Rathert, Manuel; Soler, Vicente; Bógalo Román, Mª Felicidad; Álvaro, Ana
We present initial rock magnetic results for both lava flows and lapilli produced by the 2021
eruption of the Cumbre Vieja, La Palma (Canary Islands). Samples were taken during the eruption to
minimize early alteration and weathering of the rocks and tephra. Standard procedures included
progressive alternating field and thermal demagnetization, hysteresis curves, thermomagnetic experiments, progressive acquisition of isothermal remanent magnetization (IRM), and First-Order Reversal
Curves (FORCs). Overall, our observations, including low to medium unblocking temperatures,
isothermal remanent magnetization to 1 Tesla, and the abundance of wasp-waist hysteresis loops,
strongly suggest the presence of Ti-rich titanomagnetites as the main remanence carriers in both lava
flows and lapilli, in addition to some hematite as well. Whereas the former has been directly seen
(SEM), hematite is elusive with nonmagnetic-based methods. Rock magnetic data, on a Day plot, also
reveal that the magnetic grain size tends to be larger in the lava flows than in the lapilli.
2022-07-01T00:00:00ZHigh-resolution late Middle Pleistocene paleoclimatic record from the Galería Complex, Atapuerca archaeological site, Spain - An environmental magnetic approachBógalo Román, Mª FelicidadBradák, BalázsVillalaín Santamaria, Juan JoséCalvo Rathert, ManuelGonzález Martín, Manuel IvánHeller, F.Ortega Martínez, Ana IsabelParés Casanova, Josep M.http://hdl.handle.net/10259/63562023-01-01T23:42:05Z2021-01-01T00:00:00ZHigh-resolution late Middle Pleistocene paleoclimatic record from the Galería Complex, Atapuerca archaeological site, Spain - An environmental magnetic approach
Bógalo Román, Mª Felicidad; Bradák, Balázs; Villalaín Santamaria, Juan José; Calvo Rathert, Manuel; González Martín, Manuel Iván; Heller, F.; Ortega Martínez, Ana Isabel; Parés Casanova, Josep M.
The Galería Complex is a cave sediment succession at the Atapuerca paleoanthropological site (Burgos, Spain) that offers detailed environmental information about the late Middle Pleistocene, especially the period between marine oxygen isotope stages MIS10 and MIS7. Previous studies have reconstructed the chronology and detailed the environmental development of this key succession. We introduce rock magnetic climate proxies from the sedimentary units of the Galería succession that we correlate with the global climate record as represented by the marine oxygen isotope record. The cave sediment sequence consists of five infilling phases, four of which were sampled at high resolution across a 5 m thick composite profile. We propose a novel goethite climate proxy along with a frequently used ultrafine ferrimagnetic mineral proxy for paleoclimate reconstruction and detailed chronostratigraphic correlation with isotope stages and substages MIS10/MIS10-9, MIS9e-a and MIS8. The proxies reveal new paleoenvironmental information about paleoprecipitation and indicate that MIS9e was a humid (∼650 mm/year maximum annual precipitation) and intense interglacial in northern Spain that declined in steps into the globally weak glacial stage MIS8. MIS8 consisted of drier periods with 430–510 mm/year annual precipitation and at least one humid substage (600 mm/year).
2021-01-01T00:00:00ZAn Integrated Paleomagnetic, Multimethod- Paleointensity, and Radiometric Study on Cretaceous and Paleogene Lavas From the Lesser Caucasus: Geomagnetic and Tectonic ImplicationsCalvo Rathert, ManuelBógalo Román, Mª FelicidadMorales, J.Goguitchaichvili, AvtoLebedev, Vladimir A.Vashakidze, George T.García Redondo, NataliaHerrero, E.http://hdl.handle.net/10259/61172021-12-16T14:04:54Z2021-02-01T00:00:00ZAn Integrated Paleomagnetic, Multimethod- Paleointensity, and Radiometric Study on Cretaceous and Paleogene Lavas From the Lesser Caucasus: Geomagnetic and Tectonic Implications
Calvo Rathert, Manuel; Bógalo Román, Mª Felicidad; Morales, J.; Goguitchaichvili, Avto; Lebedev, Vladimir A.; Vashakidze, George T.; García Redondo, Natalia; Herrero, E.
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)).
2021-02-01T00:00:00ZPaleointensity Results From Pliocene Lavas of the Lesser Caucasus Obtained Using the Multispecimen Parallel Differential pTRM Method: A Comparison With Thellier- Thellier and IZZI DataSánchez Moreno, Elisa MaríaCalvo Rathert, ManuelGoguitchaichvili, AvtoVashakidze, George T.Camps, PierreMorales Contreras, Juan J.Vegas Tubía, NéstorLebedev, Vladimir A.http://hdl.handle.net/10259/61162021-12-16T14:06:47Z2021-04-01T00:00:00ZPaleointensity Results From Pliocene Lavas of the Lesser Caucasus Obtained Using the Multispecimen Parallel Differential pTRM Method: A Comparison With Thellier- Thellier and IZZI Data
Sánchez Moreno, Elisa María; Calvo Rathert, Manuel; Goguitchaichvili, Avto; Vashakidze, George T.; Camps, Pierre; Morales Contreras, Juan J.; Vegas Tubía, Néstor; Lebedev, Vladimir A.
We report paleointensity results obtained with the multispecimen method (MSP) over the Pliocene sequence of Apnia (Georgia) which records a polarity reversal. Paleointensity determinations with the multispecimen technique were performed on 12 flows with the original (MSP-DB) and the domain-state corrected (MSP-DSC) protocol. Eight MSP-DSC determinations passed the proposed quality criteria. To obtain highly reliable data through the agreement between intensity values from different methods, MSP results were combined with paleointensities from a previous study with Thellier-type methods and especially strict selection criteria (RCRIT) on same flows (Sánchez-Moreno et al., 2020). Application of this multimethod procedure resulted in three new paleointensities including both MSP and Thellier-type results and an additional one obtained with two different Thellier-type methods, yielding one paleointensity of 36.9 µT in the normal-polarity, and three paleointensities between 19.2 and 24.1 µT in the reverse-polarity section. Additionally, Thellier-type data have been reinterpreted in this study with more flexible criteria (TTP) and the results combined with the MSP data. As a result, four flows yield paleointensities including MSP and Thellier-type determinations and seven include paleointensities obtained with two different Thellier-type methods. Results range from 37.2 and 44.3 μT in the normal-polarity and from 12.5 to 24.6 μT in the reverse-polarity section. Comparison of results from the four flows yielding multimethod determinations applying RCRIT criteria with those from the same flows under TTP criteria yields no significant difference in paleointensity values and their experimental uncertainty. Thus, application of a multimethod approach supports the possibility of using TTP criteria.
2021-04-01T00:00:00Z