Publication Date:
2020-02-24
Description:
Absolute chronologies of active volcanoes and consequently timescales for eruptive behaviour and
magma production form a quantitative basis for understanding the risk of volcanoes. Surprisingly, the
youngest records in the geological timescale often prove to be the most elusive when it comes to isotopic
dating. Absolute Holocene volcanic records almost exclusively rely on 14C ages measured on fossil wood
or other forms of biogenic carbon. However, on volcanic flanks, fossil carbon is often not preserved, and
of uncertain origin when present in paleosols. Also, low 14C-volcanic CO2 may have mixed with atmospheric
and soil 14C-CO2, potentially causing biased ages. Even when reliable data are available, it is
important to have independent corroboration of inferred chronologies as can be obtained in principle
using the 40K/40Ar decay system. Here we present results of a 40Ar/39Ar dating study of basaltic
groundmass in the products from the Pleistocene e Holocene boundary until the beginning of the
historic era for the north-northeastern flank of Stromboli, Aeolian Islands, Italy, identifying a short phase
of intensified flank effusive activity 7500 500 a ago, and a maximum age of 4000 900 a for the last
flank collapse event that might have caused the formation of the Sciara del Fuoco depression. We expect
that under optimum conditions 40Ar/39Ar dating of basaltic groundmass samples can be used more
widely for dating Holocene volcanic events.
Description:
The mapping of Stromboli was supported by a grant to S. Calvari
(Project V2/01, 2005-2007, funded by the Istituto Nazionale di
Geofisica e Vulcanologia (INGV) and by the Italian Civil Protection).
The sample preparation was carried out by Roel van Elsas of the
Institute of Earth Sciences, VU. The new instrumentation in the
argon laboratory Institute of Earth Sciences, VU (instrument grant
for the CO2 laser, AGES extraction line) was supported by grants
from the ISES, VU-Energy conservation fund and the Institute of
Earth Sciences). This work was partly supported by INGV through
a research grant financed by MIUR-FIRB to G.N.
Description:
Published
Description:
223-232
Description:
3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
Description:
JCR Journal
Description:
reserved
Keywords:
geochronology
;
Stromboli geology
;
04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Permalink
