SEISMIC FACIES AND ARCHITECTURE OF ICE-CONTACT SUBMARINE FANS IN HIGH-RELIEF FJORDS, TROMS, NORTHERN NORWAY

During the Late Weichselian, large marginal moraines were deposited in the Norwegian fjords. In Troms County these features are termed the S karpnes and Tromso-Lyngen moraines, respectively, and have been mapped from land into the marine environment where they were formed as ice-c ontact submarine fans. High-resolution seismic data from several fjord s have been studied and reveal a typical sediment thickness of 150-320 m for these ice-contact systems. All of the ice-contact submarine fan s were formed under similar climatic conditions, but display wide vari ation in geometry, architecture and seismic pattern. This variation is related to differences in sediment supply, the nature of the subsurfa ce of the fan (e.g. position of thresholds), basin geometry and basin depth. Based on interpretation of the different seismic facies and the architecture of the Fans, former ice-front positions have been sugges ted and a model has been presented for the formation of different type s of ice-contact submarine fans dependent upon variation in local basi n condition.