We happen to have before us, at this present moment, a geological map of Nova Scotia. Two such maps have been published, one by Messrs Alger and Jackson, of Boston, and another by Dr Gesner, late colonial geologist for the province of New Brunswick. In these maps the north-western part of the province is skirted by a fringe of old primary rocks, partly metamorphic, and sometimes fossiliferous, and resting on a back ground of igneous rocks, which cover, according to Gesner, the largest portion of this end of the province. Were we inclined to try our hand at a geological prediction, we should counsel our friends in the vale of Annapolis to look out for yellow particles along the course of the Annapolis river, and especially at the mouths and up the beds of the cross streams that descend into the valley from the southern highlands.
Nature, indeed, has given the Nova Scotians in this Annapolis valley a miniature of the more famed valley of the Sacramento. Their north and south mountains represent respectively the coast range and the Sierra Nevada of the Sacramento Basin. The tributaries in both valleys descend chiefly from the hills on the left of the main rivers. The Sacramento and the Annapolis rivers both terminate in a lake or basin, and each finally escapes through a narrow chasm in the coast ridge by which its terminating basin communicates with the open sea. The Gut of Digby is, in the small, what the opening into the harbour of San Francisco now called the “Golden Gate” and the “Narrows” is in the large; and if the Sacramento has its plains of drifted sand and gravel, barren and unpropitious to the husbandman, the Annapolis river, besides its other poor lands, on which only the sweet fern luxuriates, has its celebrated Aylesford sand plain, or devil’s goose pasture—a broad flat “given up to the geese, who are so wretched that the foxes won’t eat them, they hurt their teeth so bad.” Then the south mountains, as we have said, consist of old primary rocks, such as may carry gold—disturbed, traversed by dykes, and changed or metamorphosed, as gold-bearing rocks usually are. Whether quartz veins abound in them we cannot tell; but the idle boys of Clare, Digby, Clements, Annapolis, Aylesford, and Horton, may as well keep their eyes about them, and the woodmen, as they hew and float down the pine logs for the supply of the Boston market. A few days spent with a “long Californian Tom,” in rocking the Aylesford and other sands and gravel-drifts of their beautiful valley, may not prove labour in vain. What if the rich alluvials of Horton and Cornwallis should hide beneath more glittering riches, and more suddenly enriching, than the famed crops of which they so justly boast? Geological considerations also suggest that the streams which descend from the northern slopes of the Cobequid Mountains should not be overlooked. It may well be that the name given to Cap d’Or by the early French settlers two hundred years ago, may have had its origin in the real, and not in the imaginary presence of glittering gold.
But to return from this digression. Second, The same facts which thus enable us to predict or to suggest inquiry, serve also to test the truth or falsehood of ancient traditions regarding the former fruitfulness in gold of countries which now possess only the fading memory of such natural but bygone wealth. Our geological maps direct us to European countries, in which all the necessary geological conditions coexist, and in which, were the world still young, a geologist would stake a fair reputation on the hazard of discovering gold. But the art of extracting gold from auriferous sands is simple, and easily practised. It is followed as successfully by the black barbarians of Africa as by the whitest savages of California. The longer a country has been inhabited, therefore, by a people among whom gold is valued, the less abundant the region is likely to be in profitable washings of gold. The more will it approach to the condition of Bohemia, where gold prevailed to a great extent, and was very productive in the middle ages, though it has been long worked out, and the very localities of its mines forgotten.[[7]]
Were it to become, for example, a matter of doubtful tradition, which the historian was inclined to pass by, that in the reign of Queen Elizabeth three hundred men were employed near Elvan’s Foot—not far, we believe, from Wanlockhead in Scotland—at a place called the Gold Scour, in washing for the precious metal, who in a few summers collected as much as was valued at £100,000; or that in 1796, ten thousand pounds’ worth of gold was collected in the alluvial soil of a small district in Wicklow—the geologist would come to his aid and assure him that the natural history of the neighbourhood rendered the occurrence of gold probable, and the traditions, therefore, worthy of reliance.
Third, They explain, also, why it is that, where streams flowing from one slope of a chain or ridge of mountains are found to yield rich returns to the gold-seekers, those which descend from the opposite slope often prove wholly unproductive. In the Ural, rich mines occur almost solely on the eastern, or Siberian slope of the great chain. On the western, or European slope, a few inconsiderable mines only are worked. So, as yet, in the Sierra Nevada in California, the chief treasures occur in the feeders of the Sacramento and San Joaquin rivers, which descend from its western side. The eastern slope, which falls towards the broad arid valley of the Mormons, is as yet unfamed, and may probably never prove rich in gold. These circumstances are accounted for by the fact that, in the Ural, the older rocks, of which we have spoken as being especially gold-bearing, form the eastern slope of the ridge only, the western flank of the range being covered for the most part by rocks of a more modern epoch. The same may be the case also with the Sierra Nevada where it is still unexplored; and the Utah Lake, though remote, by its saltness lends probability to this conjecture.
Fourth, and lastly, they make clear the distinction between the “dry and wet diggins” we read of in our Californian news—why in so many countries the beds of rivers have been deserted by the gold-finders, and why the river banks, and even distant dry and elevated spots, have proved more productive than the channel itself.[[8]]
Let us attempt to realise for a moment the condition of a country like California, at the period, not geologically remote, when the gold-bearing drift was spread over its magnificent valley. The whole region was covered by the sea to an unknown depth. The snowy ridge, (Nevada,) and probably the coast ridge, also formed lines of rocky islands or peaks, which withstood the fury of the waves, and, if they were covered with ice, the wearing and degrading action also of the moving glaciers. The spoils of the crumbling rocks sank into the waters, and were distributed by tides and currents along the bottom of the valley. The narrow opening through the coast chain, by which the bay of San Francisco now communicates with the Northern Pacific, would, at the period we speak of, prevent the debris of the Nevada rocks from being washed out into the main basin of the Pacific, and this would enable the metallic, as well as the other spoils of these rocks, to accumulate in the bottom, and along the slopes of what is now the valley of California.
By a great physical change the country was lifted out of the sea, either at once or by successive stages, and it presented then the appearance of a valley long and wide, covered almost everywhere by a deep clothing of sands, gravels, and shingles, with which were intermingled—not without some degree of method, but at various depths, and in various proportions—the lumps and grains of metallic gold which had formerly existed in the rocks, of which the sands and shingles had formed a part.
And now the tiny streams, which had formerly terminated their short courses in the sea itself, flowed down the mountain slopes, united their waters in the bottom, and formed large rivers. These gradually cut their way into the superficial sands, washed them as the modern gold-washer does in his cradle, and collected, in certain parts of their beds, the heavier particles of gold which they happened to meet with in their descent. Hence the golden sands of the Sacramento and the San Joaquin, and of so many of the rivers celebrated in ancient story. But the beds of these rivers could never be the receptacle of all the gold of such a district. They derived nearly all their wealth from the sands and clays or gravels they had scooped out in forming their channels; and as these channels occupy only a small fraction of the surface of the bottoms and slopes of most river valleys, they could, or were likely to contain, only an equally small fraction of the mineral wealth of their several regions. The more ancient waters had distributed the gold throughout the whole drift of the country. The river, like a “long Tom,” had cradled a small part of it, and proved its richness. The rest of the drift, if rocked by art, would prove equally, it might be even more, productive.
It is in this old virgin drift, usually untouched by the river, that the so-called dry diggings are situated. The reader will readily understand that, while no estimate can be formed of the quantity of gold which an entire valley like that of the Sacramento and San Joaquin, or which wide sandy plains like those of Australia, may ultimately yield, yet it will require great sagacity to discover, it may even be that only accident and long lapse of time will reveal, in what spots and at what depths the gold is most abundantly accumulated, and where it will best pay the cost of extraction.