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Paleointensity determination from São Miguel (Azores Archipelago) over the last 3ka
Language
English
Obiettivo Specifico
OSA1: Variazioni del campo magnetico terrestre, imaging crostale e sicurezza del territorio
Status
Published
JCR Journal
JCR Journal
Peer review journal
Yes
Title of the book
Issue/vol(year)
/234 (2014)
Pages (printed)
1-14
Issued date
June 16, 2014
Abstract
Paleointensity data from the Atlantic Ocean are rare. We present new paleointensity data from São Mig- uel (Azores Islands, Portugal) based on 20 paleomagnetic sites from 13 lava flows emplaced over the last 3000 years. Ten lava flows are radiocarbon dated, whereas three flows were paleomagnetically dated and one site was dated using stratigraphic relations. All the samples, previously investigated to recover paleo- directions, were subjected to IZZI experiments. Importantly, the new data are internally consistent, agree with Moroccan and European datasets, and offer new constraints for global geomagnetic field models. Some of the ages of the paleomagnetically dated lava flows have been revised based on the intensity data presented here. The inferred Virtual Axial Dipole Moments (VADMs) range from 68.2 to 163.5 ZAm2. A peak in field strength with an estimated age of around 600 BC is well supported by two sites from the same flow (Furna), and is comparable to the high intensity values found in Portugal for the same age and the earlier field peak at about 1000 BC in the Levant. A gradient in VADM values with latitude from northwestern Africa and across Europe between 100 and 1000 AD is confirmed as well as its absence from between 0 to 100 AD.
Type
article
File(s)
No Thumbnail Available
Name
4. DiChiara et al._Pi Azores_PEPI_14.pdf
Type
main article
Size
2.99 MB
Format
Adobe PDF
Checksum (MD5)
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