390 Karl Pettersen — Geology of N. Norway. 



pleted by the banks of shells, that is, by a layer of about two metres 

 thick entirely composed of remains of shells of species of Molluscs 

 now living. These banks of shells, of which the formation is still 

 progressing, are observed up to an elevation of about 10 to 12 metres 

 above the present sea-level. Moreover, it may be remarked in this 

 respect that on many points along the coast there is found pumice- 

 stone washed up — in some places even in great quantities ; which 

 is still at this day continually washed up by the sea-currents, to an 

 elevation of about 26 metres above the present sea-level. 



Throughout the Quaternary period the land has been subjected to 

 an upheaving of about 120 metres, and this elevation has been con- 

 tinued down to the historic time. As to Whether the land is still 

 rising there is no positive evidence existing. In any case, it is cer- 

 tain that the elevation during the last 1000 years has been quite 

 insignificant. When it is stated in so many quarters as a geological 

 fact, that the northern part of Norway rises about one-third of a 

 metre in a century, this rate is evidently much too great. 



With respect to the question whether the elevation noticed during 

 the Quaternary period has taken place by sudden impulses, or evenly 

 and slowly, it is in any case certain that the land as regards the last 

 ten metres has risen slowly and regularly. 



The unstratified rocks which break forth through the tracts of 

 country here noticed are — 



1. The gneissoid granite of the coast-tract, which forms rela- 

 tively the greatest part of the groups of islands of the coast-tract. It 

 appears, sometimes, as a striped granite ; sometimes as a granite 

 gneiss and as gneiss granite ; but often also as pure granite, through 

 all possible transitional forms from gneiss to pure granite. The 

 felspar is usually formed of reddish orthoclase, but oligoclase occurs 

 also. The mica is most frequently brown magnesian mica. 



In some places hornblende takes the place of the mica ; and the 

 rock then goes over to hornblende-granite. Eed garnets are found 

 in some places in the gneissoid-granite. Magnetite and pyrites 

 are frequent accessory minerals. 



The gneissoid granite is often traversed by layers of quartz, which 

 are sometimes thick. In one place the granite is found traversed by 

 veins of carbonate of lime. The gneissoid granite forms most fre- 

 quently wild mountain tracts, whence there shoot up series of peaks 

 and pinnacles, the shapes of which are often very wonderful. Some 

 of these may reach to a height of about 1 300 metres. Open ways 

 or tunnels traverse many of the mountains that are formed of 

 gneissoid granite. Some of these tunnels are situated at an elevation 

 of about 500 metres above the sea-level. 



2. Inland Granite. — Various larger and smaller granitic masses 

 crop up in the interior as well in the Amt of Fininark, as in that of 

 Tromso. The Inland granite in the Amt of Tromso may often be 

 regarded as an oligoclase granite : oligoclase being here often found 

 tolerably predominant by the side of orthoclase. 



3. Gabbro or Hypersthenite crops out in thick masses in the 

 northern part of the Amt of Tromso, as also in West Finmark. The 



