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Denali fault slip rates and Holocene-late Pleistocene kinematics of central Alaska

Geology

By:
, , , , , , and
DOI: 10.1130/G22361.1

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Abstract

The Denali fault is the principal intracontinental strike-slip fault accommodating deformation of interior Alaska associated with the Yakutat plate convergence. We obtained the first quantitative late Pleistocene-Holocene slip rates on the Denali fault system from dating offset geomorphic features. Analysis of cosmogenic 10Be concentrations in boulders (n = 27) and sediment (n = 13) collected at seven sites, offset 25-170 m by the Denali and Totschunda faults, gives average ages that range from 2.4 ?? 0.3 ka to 17.0 ?? 1.8 ka. These offsets and ages yield late Pleistocene-Holocene average slip rates of 9.4 ?? 1.6, 12.1 ?? 1.7, and 8.4 ?? 2.2 mm/yr-1 along the western, central, and eastern Denali fault, respectively, and 6.0 ?? 1.2 mm/yr-1 along the Totschunda fault. Our results suggest a westward decrease in the mean Pleistocene-Holocene slip rate. This westward decrease likely results from partitioning of slip from the Denali fault system to thrust faults to the north and west. ?? 2006 Geological Society of America.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Denali fault slip rates and Holocene-late Pleistocene kinematics of central Alaska
Series title:
Geology
DOI:
10.1130/G22361.1
Volume
34
Issue:
8
Year Published:
2006
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geology
First page:
645
Last page:
648
Number of Pages:
4