I 191. No. II. THE STRAXDFLAT AXID SOSTASY. 5I 



belonging to tlie strandfiat. and wliich arc i)rul)al)ly built up of harder 

 'Archæan' rocks [cf. Nansen, 1904. pp. 42, 117 ff.j. 



East of this region, whicli coincides with the western boundary of 

 Finmarken, the typical strandfiat, near present sea-level, entirely dis- 

 appears. The outer coast is here chiefly built up of sedimentary rocks 

 and crystalline schists, less resistant to shore erosion than the igneous and 

 so-called Archæan rocks to the west and south-west. The coast suddenly 

 changes character at this boundary line between the geological formations. 

 There is no typical 'skjærgård' along the Finmarken coast; only in some 

 few places, round Ingoi and outside the north-west corner of Mageroi, 

 where more resistant 'Archæan' rocks occur, are there indications of a 

 'skjærgård' and a strandfiat at sea-level. 



The only explanation I can find of the absence of a strandfiat, near 

 present sea-level, along the coast of Finmarken, and of the remarkably 

 close relation of this absence to the change in the geological structure of 

 the coast, is that the sedimentary rocks and schists of Finmarken have 

 offered relatively little ristance to the vigorous shore erosion of this 

 northern region and to glacial erosion. During periods with a low shore- 

 line, the rocks of the outer coast have therefore been denuded to deeper 

 levels. They have also been cut away by glacial erosion. 



The outer coast of Finmarken is to a great extent very steep and 

 precipitous, forming high shore cliffs, with much oversteepened, some- 

 times almost vertical mountain walls, often some hundred metres high. 

 This is especially the case in East-Finmarken wdiere the coast consists 

 chiefly of series of dolomite-bearing sandstones and shales of great thick- 

 ness [cf. O. Holtedahl, 19 18]. This coast has obviously got its typical con- 

 figuration by a vigorous and very effectixe shore erosion. If in this region 

 the formation corresponding to the strandfiat along the Norwegian coast 

 to the south-west occurs, it may therefore be looked for at lower levels, 

 below the sea-surface, where submerged platforms actually occur at depths 

 of between 40 and 90 metres [cf. Nansen, 1904, pp. iijff.l. Tt may, 

 however, be difficult to distinguish between these platforms and the inner 

 part of the continental shelf. 



It is obviously a general feature that coasts built up of relatively weak 

 rocks, offering little resistance to shore erosion, never have a typical 

 'skjærgård', while this formation always occurs along coasts consisting of 

 harder Archæan or igneous rocks, and formerly exposed to glacial erosion. 



As examples of coasts without a 'skjærgård' besides Finmarken, I may 

 mention the coasts of Bear Island, Spitsbergen, and Iceland. These coasts 

 are mostly built up of rocks which offer relatively less resistance to shore 

 erosion, such as sandstones, shales, dolomite, limestones, basalts, etc. But 

 wherever harder igneous rocks occur, there are generally indications of a 

 'skjærgård', c. g. outside the north-west corner of Mageroi, at the north- 



