TY JOUR TI Intraplate magmatism of the De Long Islands: A response to the propagation of the ultraslow-spreading Gakkel Ridge into the passive continental margin in the Laptev Sea KW intraplate magmatism KW continental margin KW Gakkel Ridge KW Laptev Sea KW basaltic magmatism. JO Russian Journal of Earth Sciences AU Silantyev, S.A. AU Karpenko, S.F. AU Kostitsyn, Y.A. AU Bogdanovskii, O.G. AU Fedorov, P.I. PY 2004 IS 6 PB Geophysical Center of the Russian Academy of Sciences