Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/181

From Wikisource
Jump to navigation Jump to search
This page needs to be proofread.
AND CIRQUES IN NORWAY AND GREENLAND.
143

AND CIRQUES IN NORWAY AND GREENLAND. 143

layers of coal ; these formations are covered by a thick sheet of basalt. From them Professor Nordenskjold has made rich collections of fossil plants of the Cretaceous and Miocene periods ; and by exa- mining these plants Dr. Heer has shown that the climate of North Greenland must once have been subtropical, much like that now prevailing in the Canary Islands, or in Northern Egypt, with a mean annual temperature which cannot have been lower than 21° or 22° C.

In Upernivik Island, and in other places on the south side of Urnanak Fjord, one sees how the great glaciers are cutting valleys through these fossiliferous strata, and dragging down to the moraine or to the sea boulders containing the half-effaced remnants of a sub- tropical vegetation.

Like the west coast of Norway, Greenland is intersected b}' many large fjords, which, when not filled wholly or partially by glaciers, pierce deep into the country. In front of the fjords near the open sea there is a " Skiirgard " of larger and smaller islands, perfectly resem- bling the " Skiirgard " of Norway. Generally the part of Greenland nearest to the sea, or " the outer land," which is not covered by eternal snow, strikingly resembles the outermost skerries and islands on the west coast of Norway, both in the rocks and in the configura- tion of the islands. The hills around the fjords in North Greenland vary much in height, being sometimes ridges only a few hundred feet above the sea, sometimes mountains 4000 feet, and occasionally even 6000 feet or a little more.

On the whole, the part of North Greenland here described can be geologically and orographically divided into three districts : — (l)the land around Disko Bay ; (2) Disko Island, with the tableland of Niigssuak peninsula ; (3) the high land of Umanak.

(1) The land around Disko Bay consists of gneiss. It is of no great elevation, in the southern part rarely rising to 1000 feet ; in the northern part, however, in Arveprindsen Island, it rises up to 2000 feet. The islands along the coast of the district of Egedes- minde are small, low, and rounded. Two large ice-fjords intersect the mainland, that of Jakobshavn in the central part, and that of Torsukatak in the north.

(2) The configuration of the land round Disko Bay contrasts strikingly with that of Disko Island, which, as already said, is com- posed of formations belonging to the Cretaceous epoch and of basalt. The difference in rock -structure has produced a marked difference in scenery. Disko Island and Nugssuak peninsula are less cut into islets and headlands than the more undulating tracts of gneiss round Disko Bay, but form basaltic tablelands divided into two parts by the Waigat fjord, with a generally corresponding structure on either side.

No great glacier from the Inland Ice intersects this part of North Greenland, which is connected with the ice-clad inner land only by a narrow isthmus ; but very many glaciers descend into valleys from the high snow-clad interior of Disko Island and of Nugssuak penin- sula ; in both these there are mountains from 3000 to 4000 feet high. The highest basaltic mountains of Greenland are probably situated