Open AccessTephrochronology and Provenance of an Early Pleistocene (Calabrian) Tephra From IODP Expedition 374 Site U1524, Ross Sea (Antarctica)
Author(s) -
Di Roberto A.,
Scateni B.,
Di Vincenzo G.,
Petrelli M.,
Fisauli G.,
Barker S. J.,
Del Carlo P.,
Colleoni F.,
Kulhanek D. K.,
McKay R.,
De Santis L.
Publication year - 2021
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2021gc009739
Subject(s) - geology , tephra , sanidine , tephrochronology , rhyolite , geochemistry , pleistocene , provenance , volcano , caldera , pumice , paleontology , volcanic rock , biotite , quartz
We present a full characterization of a 20 cm‐thick tephra layer found intercalated in the marine sediments recovered at Site U1524 during International Ocean Discovery Program (IODP) Expedition 374, in the Ross Sea, Antarctica. Tephra bedforms, mineral paragenesis, and major‐ and trace‐element composition on individual glass shards were investigated and the tephra age was constrained by 40 Ar‐ 39 Ar on sanidine crystals. The 40 Ar‐ 39 Ar data indicate that sanidine grains are variably contaminated by excess Ar, with the best age estimate of 1.282 ± 0.012 Ma, based on both single‐grain total fusion analyses and step‐heating experiments on multi‐grain aliquots. The tephra is characterized by a very homogeneous rhyolitic composition and a peculiar mineral assemblage, dominated by sanidine, quartz, and minor aenigmatite and arfvedsonite‐riebeckite amphiboles. The tephra from Site U1524 compositionally matches with a ca. 1.3 Ma, rhyolitic pumice fall deposit on the rim of the Chang Peak volcano summit caldera, in the Marie Byrd Land, located ca. 1,300 km from Site U1524. This contribution offers important volcanological data on the eruptive history of Chang Peak volcano and adds a new tephrochronologic marker for the dating, correlation, and synchronization of marine and continental early Pleistocene records of West Antarctica.