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Tectonic subsidence of the Lomonosov Ridge

Alexander N. Minakov and Yury Yu. Podladchikov
Tectonic subsidence of the Lomonosov Ridge
Geology (Boulder) (December 2011) 40 (2): 99-102


The Cenozoic sedimentary record revealed by the Integrated Ocean Drilling Program's Arctic Coring Expedition (ACEX) to the Lomonosov Ridge microcontinent in 2004 is characterized by an unconformity attributed to the period 44-18 Ma. According to conventional thermal kinematic models, the microcontinent should have subsided to >1 km depth owing to rifting and subsequent separation from the Barents-Kara Sea margin at 56 Ma. We propose an alternative model incorporating a simple pressure-temperature (P-T) relation for mantle density. Using this model, we can explain the missing stratigraphic section by post-breakup uplift and erosion. The pattern of linear magnetic anomalies and the spreading geometry imply that the generation of oceanic crust in the central Eurasia Basin could have been restricted and confined by non-volcanic thinning of the mantle lithosphere at an early stage (ca. 56-40 Ma). In response to a rise in temperature, the mantle mineral composition may have changed through breakdown of spinel peridotite and formation of less dense plagioclase peridotite. The consequence of lithosphere heating and related mineral phase transitions would be post-breakup uplift followed by rapid subsidence to the deep-water environment observed on the Lomonosov Ridge today.

ISSN: 0091-7613
EISSN: 1943-2682
Serial Title: Geology (Boulder)
Serial Volume: 40
Serial Issue: 2
Title: Tectonic subsidence of the Lomonosov Ridge
Affiliation: University of Bergen, Department of Earth Science, Bergen, Norway
Pages: 99-102
Published: 20111208
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 33
Accession Number: 2012-012622
Categories: Solid-earth geophysics
Document Type: Serial
Bibliographic Level: Analytic
Annotation: With GSA Data Repository Item 2012036
Illustration Description: illus. incl. sketch map
N87°50'60" - N87°55'60", E136°10'00" - E139°33'00"
Secondary Affiliation: University of Lausanne, CHE, Switzerland
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 201207
Program Name: IODPIntegrated Ocean Drilling Program
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