Final published version
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Widespread tephra dispersal and ignimbrite emplacement from a subglacial volcano (Torfajökull, Iceland)
AU - Moles, J.D.
AU - McGarvie, Dave
AU - Stevenson, J.A.
AU - Sherlock, S.C.
AU - Abbott, P.M.
AU - Jenner, F.E.
AU - Halton, A.M.
PY - 2019/6/1
Y1 - 2019/6/1
N2 - The tephra dispersal mechanisms of rhyolitic glaciovolcanic eruptions are little known, but can be investigated through the correlation of eruptive products across multiple depositional settings. Using geochemistry and geochronology, we correlate a regionally important Pleistocene tephra horizon-the rhyolitic component of North Atlantic Ash Zone II (II-RHY-1)-and the Thórsmörk Ignimbrite with rhyolitic tuyas at Torfajökull volcano, Iceland. The eruption breached an ice mass > 400 m thick, leading to the widespread dispersal of II-RHY-1 across the North Atlantic and the Greenland ice sheet. Locally, pyroclastic density currents traveled across the ice surface, depositing the variably welded Thórsmörk Ignimbrite beyond the ice margin and ~30 km from source. The widely dispersed products of this eruption represent a valuable isochronous tie line between terrestrial, marine, and ice-core paleoenvironmental records. Using the tephra horizon, estimates of ice thickness and extent derived from the eruption deposits can be directly linked to the regional climate archive, which records the eruption at the onset of Greenland Stadial 15.2. © 2019 Geological Society of America.
AB - The tephra dispersal mechanisms of rhyolitic glaciovolcanic eruptions are little known, but can be investigated through the correlation of eruptive products across multiple depositional settings. Using geochemistry and geochronology, we correlate a regionally important Pleistocene tephra horizon-the rhyolitic component of North Atlantic Ash Zone II (II-RHY-1)-and the Thórsmörk Ignimbrite with rhyolitic tuyas at Torfajökull volcano, Iceland. The eruption breached an ice mass > 400 m thick, leading to the widespread dispersal of II-RHY-1 across the North Atlantic and the Greenland ice sheet. Locally, pyroclastic density currents traveled across the ice surface, depositing the variably welded Thórsmörk Ignimbrite beyond the ice margin and ~30 km from source. The widely dispersed products of this eruption represent a valuable isochronous tie line between terrestrial, marine, and ice-core paleoenvironmental records. Using the tephra horizon, estimates of ice thickness and extent derived from the eruption deposits can be directly linked to the regional climate archive, which records the eruption at the onset of Greenland Stadial 15.2. © 2019 Geological Society of America.
KW - Geochronology
KW - Thorium compounds
KW - Volcanoes
KW - Depositional setting
KW - Eruption deposits
KW - Greenland Ice Sheet
KW - North Atlantic
KW - Pyroclastic density currents
KW - Regional climate
KW - Tephra dispersal
KW - Widespread tephra
KW - Ice
U2 - 10.1130/G46004.1
DO - 10.1130/G46004.1
M3 - Journal article
VL - 47
SP - 577
EP - 580
JO - Geology
JF - Geology
SN - 0091-7613
IS - 6
ER -