Atlantic volcanic margins; a comparative study

Author(s): Eldholm, Olav; Gladczenko, Tadeusz P.; Skogseid, Jakob; Planke, Sverre
Author Affiliation(s): Primary:
University of Oslo, Department of Geology, Oslo, Norway
Volume Title: Dynamics of the Norwegian margin
Volume Author(s): Nottvedt, Arvid, editor
Source: Dynamics of the Norwegian margin, edited by Arvid Nottvedt. Geological Society Special Publications, Vol.167, p.411-428. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0305-8719. ISBN: 1-86239-056-8 CODEN: GSLSBW
Note: In English. 99 refs.; illus., incl. sects., 3 tables, geol. sketch maps
Summary: Volcanic margins in the Atlantic Ocean reveal a series of common crustal units and structural features developed during continental extension and break-up. We suggest that four main crustal zones can be recognized on volcanic margins. This tectono-magmatic zonation implies a history of development where tectonic and magmatic styles and dimensions depend on the interaction of lithospheric and asthenospheric properties and dynamics. The amount of excess igneous activity depends on the temperature and fluid content of the asthenosphere along the incipient plate boundary and the dynamic history of the lithosphere during the rift phase. An adequate understanding of the margin history requires studies of the entire rift, i.e. the conjugate margins. We also note that the spectacular wedges of seaward-dipping reflectors observed along many rifted margins are only one of many igneous features originating during the process of break-up and initial sea-floor spreading. Probably, most passive rifted margins represent intermediate cases relative to the volcanic and non-volcanic end-members. A mantle plume impinging on lithosphere already under extension emplacing Large Igneous Province-type initial oceanic crust, including an extensive extrusive cover, is considered the most likely explanation for volcanic margins. Hydrocarbon resource evaluations of volcanic margins have to include their characteristic tectono-magmatic features and their consequences for vertical motion, erosion, sedimentation, thermal and burial histories, and maturation.
Year of Publication: 2000
Research Program: DSDP Deep Sea Drilling Project
ODP Ocean Drilling Program
Key Words: 16 Structural Geology; 29 Economic Geology, Energy Sources; Asthenosphere; Atlantic Ocean; Basalts; Boreholes; Conjugate faults; Continental break-up; Continental margin; Deep Sea Drilling Project; Extension tectonics; Faults; Flood basalts; Igneous rocks; Magmatism; Mantle; Mantle plumes; Ocean Drilling Program; Passive margins; Petroleum; Petroleum exploration; Plate boundaries; Plate tectonics; Sea-floor spreading; Tectonics; Volcanic features; Volcanic rocks
Coordinates: N600000 N800000 E0200000 W0300000
Record ID: 2002002442
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