40Ar–39Ar dating of volcanogenic products from the AND-2A core (ANDRILL Southern McMurdo Sound Project, Antarctica): correlations with the Erebus Volcanic Province and implications for the age model of the core

• Published in: Bulletin of Volcanology
• Main Authors: Di Vincenzo, G., Bracciali, L., Del Carlo, P., Panter, K., Rocchi, S.
• Other Authors: Di Vincenzo, G.; Istituto di Geoscienze e Georisorse, CNR, Pisa, Italy, Bracciali, L.; Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy, Del Carlo, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia, Panter, K.; Department of Geology, Bowling Green State University, Bowling Green, OH, USA, Rocchi, S.; Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy, Istituto di Geoscienze e Georisorse, CNR, Pisa, Italy, Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy, Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia, Department of Geology, Bowling Green State University, Bowling Green, OH, USA
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer 2010
• Subjects: ANDRILL SMS; 40Ar–39Ar geochronology; Erebus volcanic province; McMurdo Sound; Lava clasts; Sedimentation rate; Tephra layers; Victoria Land Basin; 04. Solid Earth::04.04. Geology::04.04.02. Geochronology; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks; Antarctic; Mount Morning; Ross Sea; The Antarctic; Victoria Land; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/2122/6594; http://www.springerlink.com/content/h64rn2142gu83444/fulltext.html; https://doi.org/10.1007/s00445-009-0337-z

The AND-2A drillcore (Antarctic Drilling Program—ANDRILL) was successfully completed in late 2007 on the Antarctic continental margin (Southern McMurdo Sound, Ross Sea) with the aim of tracking ice proximal to shallow marine environmental fluctuations and to document the 20-Ma evolution of the Erebus Volcanic Province. Lava clasts and tephra layers from the AND-2A drillcore were investigated from a petrographic and stratigraphic point of view and analyzed by the 40Ar–39Ar laser technique in order to constrain the age model of the core and to gain information on the style and nature of sediment deposition in the Victoria Land Basin since Early Miocene. Ten out of 17 samples yielded statistically robust 40Ar–39Ar ages, indicating that the AND-2A drillcore recovered ≤230 m of Middle Miocene (∼128–358 m below sea floor, ∼11.5–16.0 Ma) and >780 m of Early Miocene (∼358–1093 m below sea floor, ∼16.0–20.1 Ma). Results also highlight a nearly continuous stratigraphic record from at least 358 m below sea floor down hole, characterized by a mean sedimentation rate of ∼19 cm/ka, possible oscillations of no more than a few hundreds of ka and a break within ∼17.5–18.1 Ma. Comparison with available data from volcanic deposits on land, suggests that volcanic rocks within the AND-2A core were supplied from the south, possibly with source areas closer to the drill site for the upper core levels, and from 358 m below sea floor down hole, with the “proto-Mount Morning” as the main source. Published 487-505 2.3. TTC - Laboratori di chimica e fisica delle rocce 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi JCR Journal reserved