Fig. 1From: 3D interpretation of helicopter-borne frequency-domain electromagnetic (HEM) data from Ramså Basin and adjacent areas at Andøya, NorwayBedrock map of Andøya (Henningsen and Tveten 1998) and location of geophysical surveys. Presently assumed western extent of Ramså Basin boundary is shown by green line. Location of various geophysical surveys and basement outcrops (see legends) are also marked. Red polygon shows a part of the HEM data chosen for quasi-3D inversionBack to article page