On the Physiographical Evolution of Spitsbergen Explaining the Present Attitude of the Coal-Horizons Author(s): Gerard De Geer Source: Geografiska Annaler, Vol. 1 (1919), pp. 161-192 Published by: Wiley on behalf of Swedish Society for Anthropology and Geography Stable URL: http://www.jstor.org/stable/519769 Accessed: 26-04-2016 10:28 UTC Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://about.jstor.org/terms JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Wiley, Swedish Society for Anthropology and Geography are collaborating with JSTOR to digitize, preserve and extend access to Geografiska Annaler This content downloaded from 128.111.121.42 on Tue, 26 Apr 2016 10:28:41 UTC All use subject to http://about.jstor.org/terms ON THE PHYSIOGRAPHICAL EVOLUTION OF SPITSBERGEN EXPLAINING THE PRESENT ATTITUDE OF THE COAL-HORIZONS. - WITH MAP AND SECTIONS - BY GERARD DE GEER T he physiographical interest, as that evolution land affords of Spitsbergen uncommonly is undoubtedly good opportunities of very for great the study of this subject owing to the rich representation of almost all the different geological systems. At the same time the whole structure of Spitsbergen is marvellously exposed in a great number of excellent sections along the nume- rous fjords and valleys, which in many directions cut through the mountain-masses, nowhere hidden by the scanty, Arctic vegetation. The plan of this paper is to describe the main structure-lines of Spitsbergen, its division into a Northern Oldland and a marginal horst along the west coast. Further an extended Cretaceous base-level plain, a great, Tertiary submergence, followed by a late Tertiary re-elevation of the horst and eastward overfolding of the adjacent table-region; considerable faulting along the west coast and the fjords, in the latter case proved by measured warpings of intra fjord-blocks, all those dislocations having determined the present attitude of the coal horizons. Finally the coast- and fjord-topography of Spitsbergen is compared with that of Scandinavia and conclusions are drawn concerning the probably analogous phy- siographical evolution of Northern Europe and the recent landconfiguration in general. The early Swedish expeditions soon made it manifest that the richest geolo- gical development was to be found in the central part of the land around the Ice Fjord and Bel Sound, and thus Swedish geologists have concentrated the main part of their work in this region, though they have also extended their investi- gations to almost all parts of the whole archipelago. The foundation of our knowledge is due to A. E. Nordenskidld and C. W. Blomstrand and is summarized in a geological sketch-map of Spitsbergen, pub- lished by Nordenski6ld in 1 866.1 1 Scale i: I ooo ooo. Stockholm, Vet. Ak. Handl., Bd 6, No. 7, x866. II Geografiska Annaler. This content downloaded from 128.111.121.42 on Tue, 26 Apr 2016 10:28:41 UTC All use subject to http://about.jstor.org/terms 162 GERARD DE GEER By the first especially geological expedition, that of 1882, it became possible to make a first attempt at combining the dispersed observations of the sketch- map into an almost continuous synthetical small-scale map; elucidating the geolo- gical structure of Spitsbergen in its main lines. This sketch-map was published by A. G. Nathorst in I888.1 Yet it was evident that without real mapping-work it would not be possible to get beyond the pioneer-stage with regard to Spitsbergen geology, and thus in 1896 the present writer returned to Spitsbergen and especially to its geologically most promising region, around the Ice Fjord, in order to make a map of that region. How this first detailed mapping work of a polar region was performed has already been related.2 How necessary these measurements were for the lo- cation of all the different geological observations becomes obvious from a com- parison between the new map and earlier small sketches, which by their defi- ciencies, even with respect to the coast-lines, and their total lack of any reliable topography and of heights naturally could not give any exact information. By the new measurements it became at last possible accurately to fix the po- sition of a great number of different observations and the height of thousands of points-i and especially that of certain characteristic layers, the attitude of which was found to show in a very striking way how the unequal upheaval of the moun- tain-blocks between the different fjord-branches was performed and thus also how the position of the fjords themselves was determined. By the mapping also a great number of dislocations were fixed, while earlier it had only been possible to indicate in a general way the existence of a few isolated ones. Also the mapping of the interesting new-found mountain folds in Oscar II Land, W of the Ice Fjord, was commenced, and many other contri- butions to the morphology were obtained. After some supplementary work during two shorter visits in 1899 and 1901o the present writer spent the summer of i908 together with the other members of the Swedish expedition of that year in completing the exploration of the Ice Fjord region.3 With the help of a geological map, published in the guide book of the geo- logical Spitsbergen excursion of the international congress in Stockholm 1910o, the present writer demonstrated in the field to some seventy foreign geologists 4 the 1 Scale I: 3 700 00ooo in: EDUARD SUESS, Das Antlitz der Erde, Bd 2, Wien 1888, p. 102. - Also in: A. G. NATHORST, Jordens historia, D. i, Sthlm 1894, p. 52. S Rapport om den svenska geol. exp. till Isfjorden pa Spetsb. sommaren 1896. Ymer. Stockholm, Arg. 16 (1896), pp. 258-266. 3 Den svenska Spetsbergsexpeditionen 1908. Ymer, Stockholm, Arg. 28 (1908), pp. 341-344. Notiser. " Den svenska Spetsbergsexkursionen 191o f6r deltagare i den I I:te internationella geologkongressen i Stockholm. Ymer, Stockholm, rg. 30 (I910o,) pp. 305---310o. This content downloaded from 128.111.121.42 on Tue, 26 Apr 2016 10:28:41 UTC All use subject to http://about.jstor.org/terms PHYSIOGRAPHICAL EVOLUTION OF SPITSBERGEN 163 main results of the Swedish Spitsbergen explorations, of which it had now be- come possible to make a more elaborate general synthesis. Later published Spitsbergen observations seem to corroborate these views, and by the help of the adjoined map and sections they were four years ago, in a lecture on the Vega-day 1915, laid before the Swedish geographical society, though in the hope of a renewed visit to Spitsbergen their publication has been somewhat postponed. The structure-lines of Spitsbergen. The oldest structure-lines in Spitsbergen run NNW-SSE, which is the general strike of the foliated Archaean rocks east of Wijde Fjord, and probably also on the North East Land. As to the north-western corner of Spitsbergen, it seems, with the data at hand, not yet possible to determine how far the crystalline rocks of this region may be metamorphic or Archaean, but the general strike seems to be about the same. The Heklahoek series, which belongs to the Ordovician and possibly also to other parts of the Cambro-Silurian system, has been strongly folded and crushed, but as a rule only moderately metamorphosed, the less so at the North East Land, where well preserved so called worm-traces and Gymnosolen have been found.' At many places in Spitsbergen dolomitic layers occur with a well pre- served oolitic structure. Still at some places where the Heklahoek layers at the first look seem to be almost undisturbed, they are intensely folded. Thus in 1882 on the south side of Hornsund I have sketched dolomitic beds with a quite horizontally lying over- fold, and have afterwards by mapping followed intense dislocations. The main axis of the Caledonian or at least post-Heklahoek folding seems to run in about the same direction as the older lines of weakness, though some- times with slight divergences, as on the northern part of Nieuw Vriesland, where the strike runs somewhat more to the NW. After a long period of denudation there followed the deposition of the earlier so-called Liefde Bay layers, of which the greatest part belongs to the Devonian, while the lowest portion has been referred by the Norwegian geologists to the upper Silurian. The whole thickness of this formation has been estimated by the Norwegians to more than io ooo m, consisting mostly of sandstones, depo- sited in shallow water and thus no doubt indicating a long continued submer- gence, going on at the same pace as the sedimentation. As it is scarcely pos- 1 Stockholm, Geol. F6ren. F6rhandl., Bd. 23 (I901), p. 532 and ibid. 29 (1917), 117. This content downloaded from 128.111.121.42 on Tue, 26 Apr 2016 10:28:41 UTC All use subject to http://about.jstor.org/terms 164 GERARD DE GEER sible to imagine how this could have happened in a lake, it seems necessary to assume that this formation was marine and had originally a great extension. An occurrence of Devonian, found by the author at Horn-Sound in 1899, showed thus that the formation named is continued southward below the younger formations and occupies more than twice the area from which it was earlier known, being in our days preserved only in a >fossa magna> between very large faults as well to the East as to the West.