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Neotectonic analysis of upper klamath lake, oregon: New insights from seismic reflection data

Special Paper of the Geological Society of America

By:
, , ,
DOI: 10.1130/2009.2447(05)

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Abstract

We present marine high-resolution seismic reflection data from Upper Klamath Lake, Oregon, to discern the underlying structure and estimate Quaternary slip rates in this actively extending Basin and Range system. The sediment patterns and structures imaged on our seismic profiles reveal a complex geologic system that reflects a changing climate record, shallow water conditions, growth faulting, contrasting sediment sources, and high slip rates. We observe that Upper Klamath Lake is a sedimentsaturated environment, and sediment accumulation rates are therefore controlled by basin subsidence rather than sediment supply. Published slip rates for Holocene extension are greater than our determined late Quaternary slip rates, assuming reasonable rates of deposition. The apparent increased Holocene fault-slip rates may be in part an artifact of long recurrence intervals between major earthquakes, with recent seismicity accommodating long-term strain. The quantity of observed faults below the lake is at least an order of magnitude greater than those mapped outside the lake, suggesting that many hidden faults throughout the region may be unaccounted for when estimating Basin and Range extension rates. Copyright ?? 2009 The Geological Society of America. All rights reserved.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Neotectonic analysis of upper klamath lake, oregon: New insights from seismic reflection data
Series title:
Special Paper of the Geological Society of America
DOI:
10.1130/2009.2447(05)
Issue:
447
Year Published:
2009
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Special Paper of the Geological Society of America
First page:
71
Last page:
82
Number of Pages:
12