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GEOREF RECORD

Effect of subducting sea-floor roughness on fore-arc kinematics, Pacific Coast, Costa Rica

Donald M. Fisher, Thomas W. Gardner, Jeffrey S. Marshall, Peter B. Sak and Marino Protti
Effect of subducting sea-floor roughness on fore-arc kinematics, Pacific Coast, Costa Rica
Geology (Boulder) (May 1998) 26 (5): 467-470

Abstract

Fault kinematics and uplift in the Costa Rican fore arc of the Middle America convergent margin are controlled to a large extent by roughness on the subducting Cocos plate. Along the northwest flank of the incoming Cocos Ridge, seafloor is characterized by short wavelength roughness related to northeast-trending seamount chains. Onland projection of the rough subducting crust coincides with a system of active faults oriented at high angles to the margin that segment the fore-arc thrust belt and separate blocks with contrasting uplift rates. Trunk segments of Pacific slope fluvial systems typically follow these margin-perpendicular faults. Regionally developed marine and fluvial terraces are correlated between drainages and across faults along the Costa Rican Pacific coast. Terrace separations across block-bounding faults reveal a pattern of fore-arc uplift that coincides roughly with the distribution of incoming seamounts. Magnitude and distribution of Quaternary uplift along the Costa Rican Pacific coast suggests that, despite a thin incoming sediment pile, the inner fore arc shows an accumulation of mass--a characteristic that may be due to underplating of seamounts beneath the fore-arc high.


ISSN: 0091-7613
EISSN: 1943-2682
Coden: GLGYBA
Serial Title: Geology (Boulder)
Serial Volume: 26
Serial Issue: 5
Title: Effect of subducting sea-floor roughness on fore-arc kinematics, Pacific Coast, Costa Rica
Affiliation: Pennsylvania State University, Department of Geosciences, University Park, PA, United States
Pages: 467-470
Published: 199805
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 21
Accession Number: 1998-033590
Categories: Solid-earth geophysicsOceanography
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. geol. sketch map
N08°00'00" - N11°15'00", W86°00'00" - W82°30'00"
Secondary Affiliation: Trinity University, San Antonio, TX, USA, United StatesUniversidad Nacional, Heredia, CRI, Costa Rica
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 199813
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