The excursion was first run as part of the International Geo-science Programme (IGCP) 512 “Neoproterozoic Ice Ages” project during the 33rd International Geological Congress, in Oslo, Norway, 2008. This guide is based on the material used for that excursion, with some comments by participants, both positive and adverse, added here.
Note that this is a guide to use in the field and is not necessarily fully understandable without actually being in front of the rocks. The aim has been to provide a comprehensive (within reason) coverage of both the typical and the atypical lithologies and sedimentary structures (sedimentary facies) in the area. The guide is not a systematic update on published ideas and interpretations, although this has been done at some outcrops. Readers are strongly encouraged to critically evaluate our interpretations in the field and to publish their own ideas.
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.