The area considered lies at three major geological boundaries. Paleogeographically, it lies at the border between the NNE-SSW-trending (all orientations are present day) Neoproterozoic to early Paleozoic continental margin of western Baltica, now exposed in the Caledonian nappes, and the contemporary WNW-ESE-trending Timanian basin, relicts of which are seen sparsely along the northern coast of Norway and Russia (Siedlecka, 1975; Siedlecka et al., 2004; Gayer and Rice, 1989). Structurally, it lies across the boundary between deformation associated with crustal shortening (thrusting) in the Scandinavian Caledonides in the west and the underlying autochthonous Baltic Shield (Gayer et al., 1987). Finally, it also lies at the border of the Scandinavian Caledonides in the west and Timanide deformation in the east (Siedlecka et al., 2004).
The Scandinavian Caledonides have been divided into an Autochthon, Lower Allochthon, Window Allochthon, Middle Allochthon, Upper Allochthon, and Uppermost Allochthon (Fig. 2). The Upper Allochthon is divided into Seve-type nappes and overlying Köli-type nappes.
Rocks including the Seve-type nappes down to the Lower Allochthon (the Baltic cover sheets and crystalline sheets of Hossack and Cooper, 1986) represent the strongly shortened Baltoscandian continental shelf, including the ocean-continent transition, overlying a late Neoproterozoic to lower Paleozoic autochthonous sedimentary sequence resting with a marked unconformity on basement rocks of the Baltic Shield. Of these units, only the Autochthon (East Finnmark Autochthon) and Lower Allochthon (Gaissa Thrust Belt), with a poorly defined parautochthonous intermediary zone, are of importance here
Figures & Tables
Neoproterozoic Glacial and Associated Facies in the Tanafjord-Varangerfjord Area, Finnmark, North Norway
The Neoproterozoic glacial deposits of north Norway (snowball Earth Marinoan-aged Smalfjord and the younger Gaskiers-aged Mortensnes Formations) are superbly documented and illustrated in this comprehensive eight-day field guide. Lodgement, banded, deformation, flow, and melt-out diamictites derived from gneissic, clastic, and dolomitic sources are described, as well as glaciomarine, proglacial, and fluvioglacial sediments. Outcrops showing glaciotectonic folds, faults, flanking structures, shear-sense criteria (sigma-clasts), fluidized sediments, pro- and subglacial channels, iceberg dump structures, ghost clasts, dropstones, ice-crystal molds, and a ?kettle hole are included. The classic glacial striations at Oaibaccanjar'ga are described in detail. Marinoan cap dolostones overlying the Smalford Formation are included. In comparison to other Neoproterozoic glacial successions, this area is easily accessible by airplane and/or car, and most outcrops occur along the roadside or can be easily reached by small boat. This volume includes information about accommodations and small boat rental, and a fascinating summary of the natural and local history.