Crustal structure of the East Siberian Continental Margin, Podvodnikov and Makarov basins based on refraction seismic data (TransArctic 1989–1991)

• The c. 1500 km long refraction and shallow reflection seismic profile, TransArctic 1989–1991 from the East Siberian shelf northwards across the Podvodnikov and Makarov basins, provide a four layer model of the crust: Layer I (Vp=1.7–3.8 km/s) of sedimentary formations of late Mesozoic and Cenozoic age; Layer II (Vp=5.0–5.4 km/s) of older sedimentary rocks on the shelf and possibly also mafic volcanics in the basins; Layer III (Vp=5.9–6.5 km/s) and Layer IV (Vp=6.7–7.3 km/s) of crystalline crust. The East Siberian margin has c. 40 km thick continental crust, mainly composed of layers III and IV, both c.15 km thick. Beneath the Podvodnikov Basin, the Moho depth varies from c. 20 km bsl at southern and northern ends to c. 30 km bsl at the centre beneath the Arlis Gap; it probably was formed by longitudinal extension of continental crust during the late Mesozoic. The edge of the Alpha-Mendeleev Ridge, separating the Podvodnikov and Makarov basins, has a crustal thickness of c. 25 km, mainly composed of layers III and IV. The deep Makarov Basin is probably composed of oceanic crust, 8–12 km thick, but includes spurs of continental crust, rifted off the Lomonosov Ridge.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Geofysik (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Geophysics (hsv//eng)

Nyckelord

refraction seismic

reflection seismic

crustal structure

Arctic Ocean

Amerasia Basin

East Siberian Margin

Podvodnikov Basin

Makarov Basin

Geofysik med inriktning mot seismologi

Geophysics with specialization in Seismology

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