Paleomagnetic studies on the lava pile between Skálavík and Álftafjörður, Northwest Iceland

Abstract

This paper focuses on the lava pile in the westernmost part of the south coast of the Ísafjarðardjúp fjord in the Northwest peninsula of Iceland, between Skálavík and Álftafjörður. New laboratory measurements on the paleomagnetism of over 60 lava flows in four profiles are utilized in the completion of a tentative polarity column for a composite section of 3.4 km thickness along Ísafjarðardjúp. The magnetic results which among other things document the occurrence of several excursions of the geomagnetic field, are consistent with other available data from the area. They also strengthen correlations with a composite section running south from Skálavík to Breiðafjörður. Some relevant previous studies on the Northwest peninsula are reviewed, with emphasis on the question whether the presence of the oldest lignite-containing sediments there is related to major volcano-tectonic events. Judging from the thickness of polarity zones, the rate of buildup of lavas below these sediments seems to have been of similar order of magnitude as elsewhere in Iceland.