Svalbard's Tertiary sedimentary record is important for the understanding of the Tertiary evolution of the entire Svalbard surroundings. Two main phases of Palaeogene sedimentation and establishment of structures have been recognized, both taking place in the West Spitsbergen trough. The first one ( transgressive-regressive cycle) resulted in the accumulation of Palaeocene-Eocene deposits, while the second one (regressive phase subsequent to the mid-late Eocene uplift) is represented by Eocene-Oligocene deposits. During the second and tectonically more active phase, sedimentation also started in small isolated grabens in the centre of the west coast horst-like uplift, e.g. in Forlandsundet-Bellsund (mid-Eocene to early Oligocene), in Renardodden and in Kongsfjorden (early Oligocene). The sediments - like those of the second phase of the West Spitsbergen trough - indicate an intense tectonic regime that finally resulted in thrust tectonics along the west coast of Spitsbergen in connection with crustal movements in the Atlantic Ocean. The mid-late Oligocene conglomerates of the Sarsbukta Formation in the Forlandsundet graben, the youngest Palaeogene sediments in Svalbard, probably mark the beginning of a third, post-thrust Tertiary phase ( Oligocene-Neogene). Similar sediments fill in the perioceanic troughs to the west of Svalbard. At the end of the Neogene, Svalbard underwent a general uplift against the background of descending movements within the perioceanic troughs.
Ju. Ja. Livšic, VNII Okeangeologija, Moika 120, SU-190121 Leningrad, USSR. Present address: Reading Str., 25, Ramat-Aviv, 69024 Tel Aviv, Israel.
Transcriptionan variant of the author's name is: Livshits.