Page:Popular Science Monthly Volume 13.djvu/786

This page has been validated.
766
THE POPULAR SCIENCE MONTHLY.

crystalline rock, with a conchoidal fracture. In other places it swells up into bosses and rounded masses which are thrust up into the overlying rocks. The outside of these masses presents a scoriaceous or slag-like appearance; in the interior the cavities are filled with infiltrated minerals. For the first two or three feet above the trap the shales which rest directly on these igneous rocks have been intensely metamorphosed, and are scarcely to be distinguished from the trap itself. At a distance of six or eight feet above the trap the shales are still very much altered and filled with a great number of small spherical masses of a dark-green mineral, resembling epidote. Midway up the sides of the ravine, which is about thirty feet deep, the shales present somewhat of their usual reddish appearance, but are traversed by a great number of irregular cavities formed by the expansion of vapor while the rocks were in a semi-plastic condition. At a distance of twenty-five or thirty feet above the trap, the shales and sandstones are changed but slightly, if at all, from their normal condition. A bed of limestone from two to three feet in thickness, which is here interstratified with the shales and sandstones where it approaches the trap, is considerably altered and forms a mass of semi-crystallized carbonate of lime. All this furnishes indisputable evidence that the igneous rocks composing the First Newark Mountain were intruded in the molten state between the layers of the stratified rocks subsequent to the consolidation of the latter; and by analogy we are justified in extending this conclusion to all the trap ridges which traverse the Triassic regions of New Jersey.

 

Agricultural and Mineral Resources of Alaska.—The following notes on the mineral and agricultural wealth of Alaska we take from a communication published in the Chronicle of San Francisco. The Territory is as yet virtually unexplored, yet gold, silver, copper, graphite, lead, iron, sulphur, and coal, have already been found in sufficient quantity to pay for working the deposits. "Eight well-defined ledges of gold-bearing quartz have been prospected on Baronoff Island, close to the town of Sitka; their owners owe their discovery and partial development to the enterprise and energy of one Haley, who was formerly a soldier of the garrison that was stationed here. Haley began to utilize his gold discoveries about three years ago by quarrying out rock and crushing it in a common hand mortar. By this primitive process he obtained money enough to support his family and pay the cost of a visit to Portland and San Francisco in search of capital to develop his mines. Little is known of that section of Alaska which lies back of the coast between Cross Sound—where the Alexander Archipelago, with its 1,100 islands, ends—and Prince William's Sound. On Prince William's Sound are several Indian villages, and several tracts of prairie-land which may be easily cultivated. Beyond this large inlet lies Kodiac and Cook's Inlet. As a fishing and agricultural district this is undoubtedly the best section of the whole Territory of Alaska. The climate is milder, the winters less severe, and the rainfall less, than in the southern counties of Scotland. Both on Kodiac and the shores of Cook's Inlet are large tracts of prairie-land, which now afford excellent pasture for cattle and sheep, and which can be easily cultivated for all the hardy vegetables, barley, and oats. Timber is abundant and easily accessible from the water. A large deposit of coal has been prospected, the quality of which is declared by Prof. Newberry to be fully equal to any coals found on the Pacific coast, not excepting those of Vancouver Island and Bellingham Bay. The Indians who come-down to the head of the inlet report large deposits of native copper a short distance inland, and exhibit ornaments and utensils of the same. Lead of sufficient purity to be moulded into bullets is also found there. The waters literally swarm with fish; and it is safe to say that there is no district of country on the whole Pacific coast which offers so many advantages for the profitable establishment of fish-canning and fish-curing works. With a comparatively moderate investment of capital, exports of fish to the value of several millions of dollars annually may be sent from Cook's Inlet, which would pay a large profit to the owners of the works, and would support many thousand fishermen, laborers, and mechanics. Nothing but the power of monopoly has hindered Alaska's growth thus far."