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Beryllium‐10 surface exposure dating of glacial successions in the Central Alaska Range
Author(s) -
Dortch Jason M.,
Owen Lewis A.,
Caffee Marc W.,
Li Dewen,
Lowell Thomas V.
Publication year - 2010
Publication title -
journal of quaternary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.142
H-Index - 94
eISSN - 1099-1417
pISSN - 0267-8179
DOI - 10.1002/jqs.1406
Subject(s) - moraine , glacial period , geology , outwash plain , glacier , pleistocene , glacial landform , quaternary , landform , terminal moraine , range (aeronautics) , surface exposure dating , geomorphology , sedimentary depositional environment , mountain range (options) , paleontology , physical geography , archaeology , geography , materials science , composite material , structural basin , financial economics , economics
Glacial landforms and outwash terraces in the Nenana River valley, Reindeer Hills and Monahan Flat in the central Alaska Range were dated with 60 10 Be exposure ages to determine the timing of Late Pleistocene glaciation. In the Nenana River valley, glaciation occurred at 104–180 ka (Lignite Creek glaciation), ca. 55 ka (Healy glaciation), and ca. 16 ka (Carlo Creek phase); glaciers retreated in the Reindeer Hills and Monahan Flat by ca. 14 ka and ca. 13 ka, respectively. The Carlo Creek moraine is similar in age to at least six other moraines in the Alaska Range, Ahklun Mountains and Brooks Range. The new data suggest that post‐depositional geological processes limit the usefulness of 10 Be methods to the latter part (≤60 ka) of the late Quaternary in central Alaska. Ages on Healy and younger landforms cluster well, with the exception of Riley Creek moraines and Monahan Flat‐west sites, where boulders were likely affected by post‐depositional processes. Copyright © 2010 John Wiley & Sons, Ltd.