The Fangst Group - Ile Formation
The Ile Formation (Upper Toarcian to Aalenian) is defined at the base of a generally upwards coarsening sequence from siltstone to sandstone, often associated with more carbonate beds. The sediments of the Ile Fm are deposited in tidal or shoreline environments. The upper boundary is defined by the mudstones of the Not Fm. The Ile Fm is present over most of Haltenbanken, with a general thickening to the west and marked thinning to the northeast.
The thickness in the type well (6507/11-3) is 64.5m and 72m in the reference well (6407/1-3). The thickness of the Ile Fm varies between 50 and 100m over most of the Haltenbanken-Trænabanken area.
Sandstone dominated successions of similar age have been reported from shallow boreholes and sea bottom sampling in the eastern part of the Trøndelag Platform. The succession is thinner, however, ranging from 30 to 60m. The formation is shale dominated in the Vega High and Helgeland Basin.
