Dawson tephra, a widespread 29‐ka marker bed, in a marine core from Patton Seamount off the Alaska Peninsula and its potential marine–terrestrial correlation. (18th December 2019)

• Record Type: Journal Article
• Authors: Aoki, Kaori
• Other Names: Abbott Peter M. guestEditor.; Jensen Britta J.L. guestEditor.; Lowe David J. guestEditor.; Suzuki Takehiko guestEditor.; Veres Daniel guestEditor.
• Is Part Of: Journal of quaternary science. Volume 35:Number 1/2(2020)
• Page Start: 93
• Page End: 101
• Publication Date: 2019-12-18
• Subjects: Dawson tephra -- Heinrich Stadial -- late Pleistocene -- marine sediment -- MIS3/2; Geology, Stratigraphic -- Quaternary -- Periodicals; Paleontology -- Quaternary -- Periodicals; 551.79
• DOI: 10.1002/jqs.3176
• Languages: English
• ISSNs: 0267-8179

Abstract

ABSTRACT: A tephra layer with normal grading in the sub‐bottom depth interval 119–122 cm in marine core SO202‐27‐6 was collected on Patton Seamount in the northeast North Pacific Ocean. Based on the geochemistry of volcanic glass shards determined by a wavelength dispersive electron probe micro‐analyser and an X‐ray fluorescence analyser, this layer is correlated to the Dawson tephra, a widespread late Pleistocene time marker tephra in Alaska and the Yukon. The age of the Dawson tephra in the core is 29.03 ± 0.178 ka (1 sigma) based on a published age model. The Dawson tephra is revealed to have been deposited in the transition from marine isotope stage 3 to 2, i.e. the last stage of Heinrich Stadial 3 derived from the ice‐rafted debris signal. According to the correlation between Greenland (NGRIP ice core) and this core, the Dawson tephra occupies the record immediately before inter stadial 4 in the δ 18 O stratigraphy of NGRIP. The Dawson tephra on Patton Seamount includes lithic fragments, which suggests that it was deposited not only by fall‐out but also in part via another mechanism, such as icebergs from the Cordilleran ice sheet or seasonal sea ice.