Prof. A. E, Nordenshibld — Geology of Spitzbergen. 19 



Similar advancing glaciers probably occur in a great many other 

 places along the coasts of Spitzbergen ; for example, the inner part of 

 the Stor Fiord, the bottom of Wahlenberg Bay, etc. It is, however, 

 probable that the advance at these places corresponds to a receding at 

 others, though it is difficult to give instances of this, on account of the 

 non-existence of old detailed, maps,-^ and that the changes which have 

 manifested themselves during the later centuries in the extent of the 

 glaciers have mainly depended on changes in the direction of the ice- 

 streams by which the inland mer de glace debouches into the sea. 

 Besides, the period of time during which direct observations have been 

 made in these regions is too short to afford us any certain information 

 as to the changes which the country has undergone in climatic and 

 geographical respects. It is by studying its rock-formation and by 

 examining the animal and vegetable remains which lie embedded in 

 its various sedimentary strata that we first obtain an idea of the 

 former state of these regions now so ice-covered. 



In giving a description of the rocks, I shall follow the order of 

 succession, and so begin with the oldest, viz. : 



I. Crystalline rocks. — The crystalline rocks (granite, granite- 

 gneiss, gneiss, crystalline limestone, mica-slate, hornblende-slate, 

 etc.), which occur at the north-western corner of Spitzbergen, at 

 Verlegen Hook, and the north-eastern shore of Wijde Bay, the north 

 coast of Nordland, the Seven Islands, and the innermost part of 

 Wahlenberg Bay, were found also in 1870 by Nathorst and Wil- 

 ander in Klaas Billen Bay, in the innermost part of it on the north- 

 east side, both on a mountain near the great glacier, and on the 

 north side of the same mountain chain round a smaller glacier. At 

 the latter place the ground-rock consists of mica- slate, gneiss, horn- 

 blende-slate, and quartzite, and is overlain unconforrtiahly by sand- 

 stone and clay-slate containing coal, followed by a stratum of red 

 and white gypsum. Near the large glacier the formation is nearly 

 the same, inasmuch as mica-slate with garnets and gneiss is over- 

 lain uncoTiformably by sandstone and bituminous slate. In the sand- 

 stone were observed a large Stigmaria or Sigillaria, and an impression 

 of a Calamites, which show that these strata belong to the Lower 

 Carboniferous series ('Ursa' stage, Heer). The above-named places 

 on Klaas Billen Bay are the only ones on Ice and Bell Sounds where 

 crystalline rocks occur in position, but erratic blocks have been found 

 in many places, and consist in some cases of a very coarse-grained 

 porphj^ry-like granite, which we have not found in sitil, though it 

 is probable it is to be found under the mer de glace in the interior. 



^ A comparison of the old Dutch maps with the present configuration of the 

 country appears, however, to show that the mer de glace on the north side of 

 Ice tSound formerly filled the whole of that arm of the Sound which is named 

 North Sound, and that thus rhe ice-coveri)!g at this place has considerably receded. It 

 is otherwise difficult to explain how Ice Sound, the next largest fiord on Spitzbergen, 

 is delineated in these maps as very small, the north arm being completely left out, 

 while the southern shore of the sound is drawn, if not correctly, at least recognizably. 

 No similar discrepancy between the old maps and the present form of the fiords 

 occurs in the case of BtU Sound, Licfde Baij, and JFiJde Bay. In Stor Fiord (Wybe 

 Jans Water) the ice, on the contrary, is thought to have advanced to the two 

 islands in the bottom of the fiord which in Van Keulen's map are named "Wahussen 

 and Robben Eyland, and which are believed to be now surrounded by ice. 



