Distribution of crustal types in Canada Basin, Arctic Ocean

Details

• Journal Title:
  Tectonophysics
• Personal Author:
  Chian, D. ; Jackson, H.R. ; Hutchinson, D.R. ; Shimeld, J.W. ; Oakey, G.N. ; Lebedeva-Ivanova, N. ; Li, Q. ; Saltus, R.W. ; Mosher, D.C.
• NOAA Program & Office:
  NESDIS (National Environmental Satellite, Data, and Information Service) ; NCEI (National Centers for Environmental Information)
• Description:
  Seismic velocities determined from 70 sonobuoys widely distributed in Canada Basin were used to discriminate crustal types. Velocities of oceanic layer 3 (6.7–7.1 km/s), transitional (7.2–7.6 km/s) and continental crust (5.5–6.6 km/s) were used to distinguish crustal types. Potential field data supports the distribution of oceanic crust as a polygon with maximum dimensions of ~ 340 km (east–west) by ~ 590 km (north–south) and identification of the ocean–continent boundary (OCB). Paired magnetic anomalies are associated only with crust that has oceanic velocities. Furthermore, the interpreted top of oceanic crust on seismic reflection profiles is more irregular and sometimes shallower than adjacent transitional crust. The northern segment of the narrow Canada Basin Gravity Low (CBGL), often interpreted as a spreading center, bisects this zone of oceanic crust and coincides with the location of a prominent valley in seismic reflection profiles. Data coverage near the southern segment of CBGL is sparse. Velocities typical of transitional crust are determined east of it. Extension in this region, close to the inferred pole of rotation, may have been amagmatic. Offshore Alaska is a wide zone of thinned continental crust up to 300 km across. Published longer offset refraction experiments in the Basin confirm the depth to Moho and the lack of oceanic layer 3 velocities. Further north, toward Alpha Ridge and along Northwind Ridge, transitional crust is interpreted to be underplated or intruded by magmatism related to the emplacement of the High Arctic Large Igneous Province (HALIP). Although a rotational plate tectonic model is consistent with the extent of the conjugate magnetic anomalies that occupy only a portion of Canada Basin, it does not explain the asymmetrical configuration of the oceanic crust in the deep water portion of Canada Basin, and the unequal distribution of transitional and continental crust around the basin.
• Keywords:
  Continental Crust Ocean Bottom Continental Crust Ocean Bottom Arctic Ocean Canada Basin Earth-Surface Processes Geophysics Oceanic Crust Potential Field Data Seismic Reflection Wide Angle Reflection/Refraction

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• Source:
  Tectonophysics, 691, 8-30
• DOI:
  https://doi.org/10.1016/j.tecto.2016.01.038
• Document Type:
  Journal Article
• Place as Subject:
  Canada Basin
• Rights Information:
  Accepted Manuscript
• Rights Statement:
  The NOAA IR provides access to this content under the authority of the government's retained license to distribute publications and data resulting from federal funding. While users may legally access this content, the copyright owners retain rights that govern the reproduction, redistribution, and re-use of this work. The user is solely responsible for complying with applicable copyright law.
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha-512:a201f4446b741bc73fbc05b488838c7c9acd22ad116e399edd7c8dfb4ce8829d44b7febe63c054684c3915e71d654add75c8dc6101a89283de69a55460afd54f
• Download URL:
  https://repository.library.noaa.gov/view/noaa/45587/noaa_45587_DS1.pdf
• File Type:
  [PDF - 48.75 MB ]