Holocene tephra from the Chukchi-Alaskan margin, Arctic Ocean: Implications for sediment chronostratigraphy and volcanic history

Abstract

Developing chronologies for sediments in the Arctic Ocean and its continental margins is an important but challenging task. Tephrochronology is a promising tool for independent age control for Arctic marine sediments and here we present the results of a cryptotephra study of a Holocene sedimentary record from the Chukchi Sea. Volcanic glass shards were identified and quantified in sediment core HLY0501-01 and geochemically characterized with single-shard electron microprobe and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). This enabled us to reveal a continuous presence of glass shards with identifiable chemical compositions throughout the core. The major input of glasses into the sediments is geochemically fingerprinted to the ~3.6 ka Aniakchak caldera II eruption (Alaska), which provides an important chronostratigraphic constraint for Holocene marine deposits in the Chukchi-Alaskan region and, potentially, farther away in the western Arctic Ocean. New findings of the Aniakchak II tephra permit a reevaluation of the eruption size and highlight the importance of this tephra as a hemispheric late Holocene marker. Other identified glasses likely originate from the late Pleistocene Dawson and Old Crow tephras while some cannot be correlated to certain eruptions. These are present in most of the analyzed samples, and form a continuous low-concentration background throughout the investigated record. A large proportion of these glasses are likely to have been reworked and brought to the depositional site by currents or other transportation agents, such as sea ice. Overall, our results demonstrate the potential for tephrochronology for improving and developing chronologies for Arctic Ocean marine records, however, at some sites reworking and redistribution of tephra may have a strong impact on the record of primary tephra deposition.

Chronostratigraphy and spatial distribution of magnetic sediments in the Chukchi and Beaufort seas since the last deglaciation

“…Based on geochemical composition (including major, trace and rare earth elements), both dacitic and andesitic populations of glasses have similar patterns to bulk analyses of dacitic and andesitic tephras of the Aniakchak II eruption in southern Alaska ((Ponomareva et al . ); V. Ponomareva, pers. comm., 2016).…”

“…a BP prominent Kamchatka KS 2 eruption in 01JPC is consistent with an early Holocene hiatus in this core (Ponomareva et al . ). Furthermore, a similar hiatus of several ka duration has been identified in a well‐dated sediment record from the Herald Canyon at the western (Siberian) part of the Chukchi margin (Pearce et al .…”

“…The correlation of the physical and magnetic parameters measured on the piston-cores (PC) and their companion trigger weight cores (TWC) suggests that about 110, 10 and Table 2. Ages from radiocarbon analyses (cores 02PC and 03PC) and cryptotephra identification (Ponomareva et al 2017). Radiocarbon ages were calibrated ages using the CALIB version 7.1 software (Stuiver & Reimer 1986; http://calib.org) and the Marine13 calibration curve (Reimer et al 2013).…”

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

“…In particular, the Old Crow tephra (124 ± 10 ka; Westgate et al , ; Preece et al , ), Dawson tephra (ca. 30 ka; Froese et al , ; Jensen et al , ), and Aniakchak II (3572 ± 4 cal bp ; Pearce et al, ; Ponomareva et al , ) are significant widespread tephras in this area.…”

Miocene to Holocene Marine Tephrostratigraphy Offshore Northern Central America and Southern Mexico: Pulsed Activity of Known Volcanic Complexes

“…Wide areal distribution across sedimentary facies boundaries, near‐instantaneous emplacement, unambiguous chemical compositions, and the presence of minerals suitable for radio‐isotopic dating make the deposits of volcanic eruptions to excellent stratigraphic marker beds in terrestrial and marine sediments. Furthermore, they provide constraints on the temporal evolution of both the volcanic source region and the ash‐containing sediment facies (e.g., Kutterolf, Freundt, Peréz, et al, ; Kutterolf, Freundt, & Peréz, ; Kutterolf, Freundt, Schacht, et al, ; Kutterolf, Liebetrau, et al, ; Kutterolf et al ; Ponomareva et al, , , ; Schindlbeck, Kutterolf, Freundt, Alvarado, et al, ; Schindlbeck, Kutterolf, Freundt, Andrews, et al, ; Schindlbeck, Kutterolf, Freundt, Straub, et al, ).…”