Paleomagnetism from Deception Island (South Shetlands archipelago, Antarctica), new insights into the interpretation of the volcanic evolution using a geomagnetic model

• Published in: International Journal of Earth Sciences
• Main Authors: Oliva-Urcia, Belén, Gil Peña, Inmaculada, Maestro González, Adolfo, López Martínez, Jerónimo, Galindo Zaldívar, Jesús, Soto Marín, Ruth Lourdes, Gil Imaz, Andrés, Rey, J., Pueyo Anchuela, Óscar
• Other Authors: Plan Español de I+D+i, España
• Format: Other/Unknown Material
• Language: English
• Published: Springer 2020
• Subjects: Paleomagnetic dating; Volcanism; Caldera; Quaternary; Bransfield Strait; Antarctic Peninsula; Antarctic; Bransfield Trough; Deception Island; Estrecho; isla Decepción; islas Shetland del Sur; Shetland del Sur; Antarc*; Antarctica; Antártida
• Online Access: https://hdl.handle.net/20.500.12468/725; https://doi.org/10.1007/s00531-015-1254-3

Deception Island shows the most recent exposed active volcanism in the northern boundary of the Bransfield Trough. The succession of the volcanic sequence in the island is broadly divided into pre- and post-caldera collapse units although a well-constrained chronological identification of the well-defined successive volcanic episodes is still needed. A new paleomagnetic investigation was carried out on 157 samples grouped in 20 sites from the volcanic deposits of Deception Island (South Shetlands archipelago, Antarctic Peninsula region) distributed in: (1) volcanic breccia (3 sites) and lavas (2 sites) prior to the caldera collapse; (2) lavas emplaced after the caldera collapse (10 sites); and (3) dikes cutting pre- and the lowermost post-caldera collapse units (5 sites). The information revealed by paleomagnetism provides new data about the evolution of the multi-episodic volcanic edifice of this Quaternary volcano, suggesting that the present-day position of the volcanic materials is close to their original emplacement position. The new data have been combined with previous paleomagnetic results in order to tentatively propose an age when comparing the paleomagnetic data with a global geomagnetic model. Despite the uncertainties in the use of averaged paleomagnetic data per volcanic units, the new data in combination with tephra occurrences noted elsewhere in the region suggest that the pre-caldera units (F1 and F2) erupted before 12,000 year BC, the caldera collapse took place at about 8300 year BC, and post-caldera units S1 and S2 are younger than 2000 year BC. Departamento de Geología y Geoquímica, Universidad Autónoma de Madrid, España Instituto Geológico y Minero de España, España Departamento de Geodinámica, Universidad de Granada, España Instituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas, España Instituto Andaluz de Ciencias de la Tierra, Universidad de Granada, España Unidad de Zaragoza, Instituto Geológico y Minero de España, España Área de ...