TY - JOUR
T1 - Paleomagnetism of Holocene lava flows from the Reykjanes Peninsula and the Tungnaá lava sequence (Iceland)
T2 - implications for flow correlation and ages
AU - Pinton, Annamaria
AU - Giordano, Guido
AU - Speranza, Fabio
AU - Þórðarson, Þorvaldur
N1 - Publisher Copyright:
© 2017, Springer-Verlag GmbH Germany, part of Springer Nature.
PY - 2018/1/1
Y1 - 2018/1/1
N2 - The impact of Holocene eruptive events from hot spots like Iceland may have had significant global implications; thus, dating and knowledge of past eruptions chronology is important. However, at high-latitude volcanic islands, the paucity of soils severely limits 14C dating, while the poor K content of basalts strongly restricts the use of K/Ar and Ar/Ar methods. Even tephrochronology, based on 14C age determinations, refers to layers that rarely lie directly above lava flows to be dated. We report on the paleomagnetic dating of 25 sites from the Reykjanes Peninsula and the Tungnaá lava sequence of Iceland. The gathered paleomagnetic directions were compared with the available reference paleosecular variation curves of the Earth magnetic field to obtain the possible emplacement age intervals. To test the method’s validity, we sampled the precisely dated Laki (1783–1784 AD) and Eldgjà (934–938 AD) lavas. The age windows obtained for these events encompass the true flow ages. For sites from the Reykjanes peninsula and the Tugnaá lava sequence, we derived multiple possible eruption events and ages. In the Reykjanes peninsula, we propose an older emplacement age (immediately following the 870 AD Iceland Settlement age) for Ogmundarhraun and Kapelluhraun lava fields. For pre-historical (older than the settlement age) Tugnaá eruptions, the method has a dating precision of 300–400 years which allows an increase of the detail in the chronostratigraphy and distribution of lavas in the Tugnaá sequence.
AB - The impact of Holocene eruptive events from hot spots like Iceland may have had significant global implications; thus, dating and knowledge of past eruptions chronology is important. However, at high-latitude volcanic islands, the paucity of soils severely limits 14C dating, while the poor K content of basalts strongly restricts the use of K/Ar and Ar/Ar methods. Even tephrochronology, based on 14C age determinations, refers to layers that rarely lie directly above lava flows to be dated. We report on the paleomagnetic dating of 25 sites from the Reykjanes Peninsula and the Tungnaá lava sequence of Iceland. The gathered paleomagnetic directions were compared with the available reference paleosecular variation curves of the Earth magnetic field to obtain the possible emplacement age intervals. To test the method’s validity, we sampled the precisely dated Laki (1783–1784 AD) and Eldgjà (934–938 AD) lavas. The age windows obtained for these events encompass the true flow ages. For sites from the Reykjanes peninsula and the Tugnaá lava sequence, we derived multiple possible eruption events and ages. In the Reykjanes peninsula, we propose an older emplacement age (immediately following the 870 AD Iceland Settlement age) for Ogmundarhraun and Kapelluhraun lava fields. For pre-historical (older than the settlement age) Tugnaá eruptions, the method has a dating precision of 300–400 years which allows an increase of the detail in the chronostratigraphy and distribution of lavas in the Tugnaá sequence.
KW - Basaltic lava flows
KW - Dating
KW - Paleomagnetism
KW - Reykjanes peninsula
KW - Tungnaá lava sequence
UR - http://www.scopus.com/inward/record.url?scp=85038928384&partnerID=8YFLogxK
U2 - 10.1007/s00445-017-1187-8
DO - 10.1007/s00445-017-1187-8
M3 - Article
AN - SCOPUS:85038928384
SN - 0258-8900
VL - 80
JO - Bulletin of Volcanology
JF - Bulletin of Volcanology
IS - 1
M1 - 10
ER -