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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:49 |
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Conference: Bucharest University Faculty of Physics 2010 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Paleomagnetic study of the Quaternary Racos volcanic structure
Authors:
Andreea Craiu (1,2), C. Panaiotu (1)
Affiliation:
(1) University of Bucharest, Faculty of Physics, P.O. Box MG-11, RO-077125 Bucharest-Magurele, Romania,
(2) National Institute for Earth Physics, P.O. Box MG-2, 077125, Bucharest-Magurele, Romania
E-mail
atugui@infp.ro
Keywords:
paleomagnetism, rockmagnetism, Cobb Mountain geomagnetic event, Quaternary lava flows, East Carpathians
Abstract:
The alkali basaltic volcanism in the Persani Mountains (46°N, 25.2°E), although of modest extensions (ca. 22x8 km), represents an important Quaternary alkali basaltic province inside the Carphatians and south-eastern Europe. In this study we present new paleomagnetic and rockmagnetic results from the Racos Quarry, one of the most important volcanic structures from this complex. Both existing K-Ar ages and the new Ar-Ar ages in progress suggest that the age of this volcanic structure is around 1.2 Ma. Detalied rockmagnetic measurements (field and temperature dependence of the magnetic susceptibility, hysteresis properties and FORC diagrams) and AF and thermal demagnetizations were performed to constrain magnetic mineralogy and the structure of the natural remanent magnetization. The distribution of the Virtual Geomagnetic Poles (VGP) is clustering in the central part of the Indian Ocean. This distribution is compatible with the VGP path recorded by various sedimentary records of the Cobb Mountain geomagnetic event (around 1.9 Ma). These are the first results obtained from volcanic rocks which can be used to constrain the beginning and duration of reversed – normal polarity transition during the Cobb Mountain geomagnetic event.
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