Local formations. In various parts of the country we meet with extensive and highly-remarkable beds, geologically established with special local designations, and which, on the discovery of fossils indicating the sections, will, no doubt, at some later period be classed under the names given to the great and generally accepted formations with more precision than is possible at present. Such are, farthest north, the Gaisa series and the Raipas series in Finmark; in the Throndhjem region, the older of the Throndhjem schists, conglomerate and the sandstone series, and the Gula schists; in central Norway, environing the Jotun Fjelde, the alpine quartz. Of Mesozoic beds (Oxford clay) a few only still remain on the island of Andö in Vesteraalen; they consist of sandstone, coal, and oil-shale, with embedded Jurassic fossils.
Eruptive rocks,—granite. The eruptive rocks—granite, syenite, porphyry, gabbro, norite, serpentine, greenstone, &c.—have broken through the beds of the various formations in a variety of ways, at one time as vast masses in continuous streams, at another time as isolated dome-like summits or simply cutting up wards as dykes. Old granite occurs in Christiansand stift, Thelemark, the Hardanger Waste, where it extends over extensive tracts and at its boundaries is seen to break through the Archaean formation, sending off multitudinous coarse-grained dykes, as also on the east side of the mouth of Christiania Fjord, in Aadal and in Hedal, south of Valders, and in Österdal. Very extensive tracts of granite are met with along the coast of Romsdal and in Nordre Throndhjem amt, where the coast, called Fosen, exhibits its characteristic rounded forms. Up through Nordland we pass numerous granite tracts of considerable extent. The whole of the Lofotens and Vesteraalen, together with all the outermost islets, holms, and skerries along the coast of Nordland, consist exclusively of granite. The interior of Finmark also has very large granite tracts. Extensive masses of post-Silurian granite and syenite, as also of porphyry in sheets, occur to the west and north of Christiania Fjord; it is at the borders of these masses that the Silurian system here becomes prominent. The largest tract of gabbro is that of the Jotun Fjelde; this rock is also met with extensively in Throndhjem stift and in Tromsö stift. Norite occurs chiefly near Sogne Fjord and at Egersund. Serpentine, in tracts of very considerable extent, is met with principally throughout Throndhjem stift. Dykes of post-Silurian porphyry, but more especially of greenstone, pierce in large numbers the Silurian system of eastern Norway; similar dykes, however, are also seen here and there throughout the country traversing both schist and granite.
Minerals. Notwithstanding its great abundance of rocks, Norway cannot be said to be rich in valuable ores or minerals. Thus, for example, true coal does not occur; Jurassic has been found on Andöen, but only in seams extremely limited in extent. Gold is met with very sparingly in veins of quartz at Eidsvold, in the rivers of Finmark, and along with silver in the Kongsberg mines. The latter metal is found as native silver in veins of calcareous spar at Kongsberg, where the state owns a silver mine of considerable value. Copper occurs in numerous localities, as Thelemark, Röros in the Throndhjem district, many parts of the west coast, more especially at Vigsnæs on Karmöen, and in northern Norway at Kaafjord in Alten. Nickel is produced in some parts from sulphuretted iron ore, particularly on the island of Senjen in Tromsö amt. Iron ores are met with in southern Norway, particularly along the coast near Arendal. According to the geological survey, the presence of ore is intimately connected with the eruptive rocks, at the limits of which they are accordingly to be looked for, both in the Archæan and in the later formations; thus on the confines of the oldest granite we find alike iron and copper ore; on those of gabbro, sulphuretted iron ore containing nickel and apatite.
Volcanoes, in a strict sense, and their subsequent results, such as hot springs, have not been met with in Norway.
Geological changes. The portion of the earth's crust now visible in Norway has obviously in the lapse of time undergone very great changes with respect to the position of its parts, their level, and their surface. Both the oldest formation and the later systems are almost every where greatly bent, compressed, and distorted, and also denuded, and their parts forcibly dislocated, alike as regards situation and relative height. Formations that in the interior lie at a height of several thousand feet are on the coast found level with the surface of the sea. Strata resting on the summits bordering a lake or the shores of a fjord are again seen on islands in such lakes or fjords, and level with the surface of the latter. One side of a valley exhibits a profile which, in regard to the height of the various strata, differs materially from the profile of the opposite side. The whole rocky sheet is cut up in various directions, and the several laminæ are now sunk beneath, now raised above, those adjoining them. These dislocations have been occasioned by fissures, which in many places can be pointed out, and the number of such provable faults of dislocation increases almost every year. The direction of the fissures is manifestly of the greatest assistance in indicating the form exhibited by the surface of the country. The subsidence between two fissures produces a valley, a fjord, its rise on the other hand a height, a promontory. Professor Kjerulf has succeeded in showing that the entire system embracing the valleys and fjords of southern Norway may be easily referred to four principal directions, corresponding very nearly to the four quarters of the globe, round which the principal directions of the valleys and fjords are found grouped with predominant frequency. The same applies to northern Norway, and can also be shown to distinguish the fjords of Spitzbergen, Iceland, and Greenland; the same directions are again met with in the lines of the Icelandic volcanoes, springs, lava-dykes, and volcanic eruptions.
Influence of the ice age. Vestiges left by the ice age are very conspicuous and varied throughout Norway. The rock-surface exhibits almost everywhere, and more especially when sheltered by loose superincumbent layers, a ground, polished, and striated aspect; up to a height of 4000 to 5000 feet the striation runs in the direction of the valleys, or from the lofty inland tracts, towards the sea. Boulders of foreign origin are found scattered over the mountains, in the fields, and in the loose layers covering the surface; their origin can often be determined with certainty. Old moraines, consisting of gravel-walls lying transversely to the direction of the striæ, indicate by their position the fronts of the ancient glaciers, and by their numerous serial lines an equal number of breaks in the retreat of the ice into the country. Layers of clay and banks of mussel-shells, in which are embedded the remains of arctic marine animals, indicate the sedimentary deposit of the material carried down by the rivers of the ancient glaciers to the sea.
Snow-masses. At the present day perpetual snow is found in Norway only in elevated localities. The most celebrated masses are the following—(1) the Justedalsbræ, between Sogne Fjord and Nord Fjord. It occupies an area of 580 square miles, reaches an altitude of 5000 feet, descends with its snow-cap to between 4000 and 4500 feet, and sends off numerous glaciers on either side; several of these extend very nearly down to the sea, as the Boiumbræ in Fjærland, in Sogn, 426 feet above the sea; the largest of the Justedal glaciers is the Nigardsbræ. (2) The Folgefon, between Hardanger Fjord (Sör Fjord) and Aakre Fjord, with an area of 108 square miles and an altitude of 5270 feet. It sends off only three glaciers. (3) Hallingskarvet. (4) The snow-fields of the Jotun Fjelde, east of Sogne Fjord. (5) The snow-fields of Snæhætten. (6) The Store Börge Fjeld in Helgoland. (7) Svartisen, the largest snow -field but one in Norway, between Ranen Fjord and Salten Fjord in Nordland. It sends off a number of glaciers, some of which reach almost to the sea-level at the heads of the fjords. (8) The Sulitjelma snow-field, east of Salten Fjord, on the Swedish frontier. (9) The Jökul Fjeld, between Kvænang Fjord and Ox Fjord, on the boundary of Finmark. It sends off magnificent glaciers towards the sea. One of these, in Jökel Fjord, a branch of Kvænang Fjord, extends down to the water's edge, so that fragments of its ice fall into the fjord and float as small icebergs on the surface, the sole instance of the kind in Norway. (10) Seilarid snow-field, on the island of Seiland, near Hammerfest, the most northerly névé in Europe. The limit of perpetual snow in Norway is estimated at 3080 feet on the island of Seiland, 5150 feet on the Dovre Fjeld, from 4100 to 4900 feet on the Jotun Fjelde, from 3100 to 4100 feet on the Justedal snow-fields, and from 3100 to 4100 feet on the Folgefon.
Marine terraces, beach-lines. Traces of relative changes of level between land and sea are observed in numerous localities. The highest marine terraces (in which the remains of marine animals have been found) are met with in the east part of the country and near Throndhjem at 600 feet above the sea-level; at the heads of the fjords on the west coast
