PROF. NORDENSKIOLD, EXPEDITION TO GREENLAND. 421 



manner as is now the case with the eastern coast of Asia and the 

 western of America, thus confirming the division of land and 

 water in the Tertiary Period, which upon totally different grounds 

 has been supposed to have existed. 



This formation appears most developed in North Greenland to 

 the large island of Disko and the peninsulas of Noursoak and 

 Sortenhook [Svartehuk ?], where it occupies an area of about 

 7,000 square miles, with a vertical section of 3,000 to 6,000 feet. 



Here these eruptive rocks are divided into beds, which, between 

 Godhavn and Fortune Bay, rest immediately upon the gneiss ; 

 but on the coast of Omenakfjord, between Ekkorfat and Kome, 

 upon sand- and clay-beds"^belonging to the Cretaceous age. To the 

 east of Godhavn, at Puilasok and Sinnifik, we meet with sand- 

 and clay-beds lying between, not under, the basaltic rocks, and 

 accordingly newer than some of the latter. The fossils in these 

 beds belong to the Tertiary Period. It follows, then, that the 

 eruptions, which have given rise to these vast beds of basalt, have 

 taken place subsequently to the commencement of the Cretaceous, 

 and have ceased before the termination of the Tertiary Period, 



In the preceding pages I have intentionally spoken of basaltic 

 strata or beds. In almost every place where I have had the 

 opportunity of examining it, the Greenland basalt is so stratified 

 that one is forced to admit that it is only exceptionally that we 

 have to do with masses of lava, but for the most part with sedi- 

 mentary beds of volcanic ashes and volcanic sand, which in the 

 course of thousands of years have become hard and assumed a 

 crystalline structure. 



Decided lava-streams I have scarcely observed ; even large or 

 small dykes are not so conmion as one might expect ; and, where 

 they are found, the mass of lava has produced scarcely any effect 

 upon the loose beds of sand or clay, or the basalt that it has 

 pierced. 



No volcanoes, either extinct or active, are met with in these 

 parts, although circular depressions in the basalt plateau, caused 

 by glaciers or brooks, may, when carelessly observed, easily be 

 mistaken for true craters. It is, of course, quite natural that 

 great cavities in the interior of the earth must arise in the places 

 whence the great eruptions have issued, which have produced the 

 basalt region of Greenland ; and that these in their turn must, 

 within a short period, be followed by the destruction of the super- 

 jacent volcanic cone. The place or places where these old volca- 

 noes once rose high over the surrounding plains will therefore 

 now most probably correspond with the greatest depths in the 

 neighbouring sea. 



At Godhavn the lowest strata resting immediately upon the 

 gneiss formation {e.g. outside Blasedalen) consist of a basalt-tuff* or 

 breccia, containing various species of zeolites (according to Giesecke 

 only apophyllite), next comes columnar basalt, free from zeolites, 

 then again basalt-tuff" with zeolites, alternating with true basalt. 

 A coarse crystalline dolerite, very similar to the Spitzbergen 



