The ‘‘large sample method’’ of archeomagnetic dating was applied to Stromboli. 127 samples (10 sites) yielded paleofield directions with 95% confidence intervals less than 2. Coupled with a reference curve for secular variation in western Europe, these allow accurate dating of volcanic events. A lava flow underlying San Bartolo village gave a minimum age of AD 100 (±100); a lava overflow predating the last sector collapse was dated from 1350 (±60), suggesting the recent occurrence of highly hazardous events. Lava spatters and a hot avalanche high on the northern flank were emplaced during the XXth century; lava spatters on the lower flanks could date the onset of the stillongoing phase from AD 550 (±50). These results are different from those obtained in a recent study, probably because traditional paleomagnetic sampling cannot yield sufficient precision, considering the characteristics of the archeomagnetic secular variation curve. INDEX TERMS: 1503 Geomagnetism and Paleomagnetism: Archeomagnetism; 1522 Geomagnetism and Paleomagnetism: Paleomagnetic secular variation; 1560 Geomagnetism and Paleomagnetism: Time variations—secular and long term; 1594 Geomagnetism and Paleomagnetism: Instruments and techniques; 8419 Volcanology: Eruption monitoring (7280).
Recent eruptive history of Stromboli (Aeolian Islands, Italy) determined from high-accuracy archeomagnetic dating
S. ARRIGHI;ROSI, MAURO;
2004-01-01
Abstract
The ‘‘large sample method’’ of archeomagnetic dating was applied to Stromboli. 127 samples (10 sites) yielded paleofield directions with 95% confidence intervals less than 2. Coupled with a reference curve for secular variation in western Europe, these allow accurate dating of volcanic events. A lava flow underlying San Bartolo village gave a minimum age of AD 100 (±100); a lava overflow predating the last sector collapse was dated from 1350 (±60), suggesting the recent occurrence of highly hazardous events. Lava spatters and a hot avalanche high on the northern flank were emplaced during the XXth century; lava spatters on the lower flanks could date the onset of the stillongoing phase from AD 550 (±50). These results are different from those obtained in a recent study, probably because traditional paleomagnetic sampling cannot yield sufficient precision, considering the characteristics of the archeomagnetic secular variation curve. INDEX TERMS: 1503 Geomagnetism and Paleomagnetism: Archeomagnetism; 1522 Geomagnetism and Paleomagnetism: Paleomagnetic secular variation; 1560 Geomagnetism and Paleomagnetism: Time variations—secular and long term; 1594 Geomagnetism and Paleomagnetism: Instruments and techniques; 8419 Volcanology: Eruption monitoring (7280).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
