https://cir.cenieh.es/handle/20.500.12136/41 Fri, 24 Jul 2026 22:47:12 GMT 2026-07-24T22:47:12Z https://cir.cenieh.es/handle/20.500.12136/3338 Title: Early Sri Lankan coastal site tracks technological change and estuarine resource exploitation over the last ca. 25,000 years Authors: Amano, Noel; Faulkner, Patrick; Wedage, Oshan; Clarkson, Chris; Amila, Dambara; Val Blanco, Miren del; Jurkenas, Dovydas; Kapukotuwa, Alexander; López, Gloria I.; Parés, Josep María; Pathmalal, M. M.; Smith, Tam; Wright, Martin; Roberts, Patrick; Petraglia, Michael; Boivin, Nicole Abstract: The island of Sri Lanka was part of the South Asian mainland for the majority of the past 115,000 years, and connected most recently during the Last Glacial Maximum via the now submerged Palk Strait. The degree to which rising sea levels shaped past human adaptations from the Pleistocene and into the mid to late Holocene in Sri Lanka has remained unclear, in part because the earliest reliable records of human occupation come from the island's interior, where cave sites have revealed occupation of tropical forest ecosystems extending back to 48 thousand years (ka). The island's earliest known open-air sites are all much younger in date, with ages beginning at 15 ka and extending across the Holocene. Here we report the earliest well-dated open-air coastal site in Sri Lanka, Pathirajawela, which records human occupation back to ca. 25,000 years ago. We show that humans at Pathirajawela consistently adapted to changing ecosystems linked to sea level transgression and coastal evolution from the Last Glacial Maximum into the Holocene. The presence of anthropogenic shell midden deposits at the site from ca. 4.8 ka, focused almost exclusively on a single taxon, indicates intensification of estuarine resource exploitation, as humans responded to opportunities presented by the formation of new coastal ecosystems. Fri, 01 Nov 2024 00:00:00 GMT https://cir.cenieh.es/handle/20.500.12136/3338 2024-11-01T00:00:00Z https://cir.cenieh.es/handle/20.500.12136/3312 Title: Reliability of the paleomagnetic signal recorded in a lava flowerupted on 4 December 2021 in La Palma (Canary Islands, Spain) Authors: Calvo-Rathert, Manuel; Vernet, Eva; Parés, Josep María; Soler, Vicente; Sánchez-Moreno, Elisa-María; Bógalo, María-Felicidad; Carrancho, Ángel; Yamamoto, Yuhji; RodrÍguez-Méndez, Lidia Abstract: Summary A basaltic lava flow erupted from the Tajogaite volcano on December 4th, 2021, in La Palma (Canary Islands, Spain) was sampled to find out to what extent reliable and correctinformation on both intensity and direction of the Earth's magnetic field can be obtained from the paleomagnetic 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. Paleomagnetic experiments showed a strong viscous overprint in many samples. Nevertheless, the mean paleomagnetic 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 paleointensity 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$\mu$T (IGRF-13). However, paleointensities of 60\% 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 paleointensity result B = (36.9 $\pm$ 2.0) $\mu$T in good agreement with the expected field intensity. Mon, 01 Jan 2024 00:00:00 GMT https://cir.cenieh.es/handle/20.500.12136/3312 2024-01-01T00:00:00Z https://cir.cenieh.es/handle/20.500.12136/3364 Title: Registro arqueomagnético de baldosas de viviendas afectadas por la erupción de 2021 del volcán Tajogaite (La Palma, Canarias) Authors: Carrancho, Á.; Calvo Rathert, M.; Parés, Josep María; Soler, V.; Vernet, E.; Bógalo, M.F.; Sánchez Moreno, E.M. Abstract: La erupción en 2021 del volcán Tajogaite en la isla de La Palma (Canarias) arrasó cultivos, casas y otras propiedades. El objetivo de esta investigación es determinar si la lava generó cambios distinguibles en el registro magnético original de baldosas de viviendas afectadas por la colada. Esto tiene interés no sólo para evaluar el impacto de erupciones volcánicas en contextos similares, sino que también permite contrastar el método ya que las condiciones y fecha de la erupción son conocidas. Se recogieron baldosas orientadas de varias viviendas distinguiendo dos tipos según su color (grises y rojas). El principal portador de la magnetización es magnetita escasamente substituida con contribuciones variables de hematites, según el tipo y color de baldosa. Ambos tipos de baldosas son altamente magnéticas y exhiben diagramas de desmagnetización estables y univectoriales. Únicamente se han identificado termorremanencias parciales con máximas temperaturas de desbloqueo de entre 400 – 500 ºC en alguna baldosa gris. La dirección arqueomagnética obtenida en ambos tipos de baldosas es similar a la esperada, aunque parece haber cierta infraestimación en la inclinación. Se están realizando análisis de anisotropía de la TRM para determinar si hay algún efecto al respecto y corregirlo. También se están realizando análisis de arqueointensidad absoluta mediante el método Thellier-Coe con el fin de evaluar si estos materiales han registrado fielmente la intensidad del campo magnético terrestre. Se demuestra cómo el calentamiento a alta temperatura de la lava sobre estas baldosas ha generado una nueva TRM que reseteó su magnetización original. No obstante, la identificación ocasional de pTRMs es un método efectivo para determinar la última temperatura de recalentamiento. Description: Ponencia presentada en: XI Congreso Geológico de España Sun, 01 Dec 2024 00:00:00 GMT https://cir.cenieh.es/handle/20.500.12136/3364 2024-12-01T00:00:00Z https://cir.cenieh.es/handle/20.500.12136/2937 Title: Environmental Reconstruction from the Identification of Magnetic Minerals in the Upper Sedimentary Infill of the Gran Dolina Cave (Burgos, Spain) Authors: D’Arcangelo, Serena; Martín-Hernández, Fátima; Parés, Josep María Abstract: The cave system in the Sierra de Atapuerca holds one of the most important archaeological sites for the understanding of early human occupation in Europe. Among the different cavities and galleries, the Gran Dolina cave yielded a new hominin species coined as Homo antecessor of an Early Pleistocene age. Encouraged by our previous results in Gran Dolina, we carried out a study to extend and deepen our rockmagnetic investigation of the paleoenvironmental reconstruction of the upper Gran Dolina cave based on experiments that include composition, relative concentration, and grain size of the magnetic iron oxides present in the sediments. Based on the rockmagnetic experiments, we identified magnetite, hematite, goethite, and possibly maghemite in changeable amounts along the profile, which allows us to complement the existing shortage in the literature on the palaeoenvironmental reconstruction of the site. We tentatively interpret the rockmagnetic changes recorded in the cave sediments in terms of glacial/interglacial conditions, furnishing the base for a better understanding for the formation conditions of this unprecedented archaeological site. Sat, 01 Apr 2023 00:00:00 GMT https://cir.cenieh.es/handle/20.500.12136/2937 2023-04-01T00:00:00Z