第10章 III(2)

Shasta is a fire-mountain, an old volcano gradually accumulated and built up into the blue deep of the sky by successive eruptions of ashes and molten lava which, shot high in the air and falling in darkening showers, and flowing from chasms and craters, grew outward and upward like the trunk of a knotty, bulging tree. Not in one grand convulsion was Shasta given birth, nor in any one special period of volcanic storm and stress, though mountains more than a thousand feet in height have been cast up like molehills in a night--quick contributions to the wealth of the landscapes, and most emphatic statements, on the part of Nature, of the gigantic character of the power that dwells beneath the dull, dead-looking surface of the earth.

But sections cut by the glaciers, displaying some of the internal framework of Shasta, show that comparatively long periods of quiescence intervened between many distinct eruptions, during which the cooling lavas ceased to flow, and took their places as permanent additions to the bulk of the growing mountain. Thus with alternate haste and deliberation eruption succeeded eruption, until Mount Shasta surpassed even its present sublime height.

Then followed a strange contrast. The glacial winter came on. The sky that so often had been darkened with storms of cinders and ashes and lighted by the glare of volcanic fires was filled with crystal snow-flowers, which, loading the cooling mountain, gave birth to glaciers that, uniting edge to edge, at length formed one grand conical glacier--a down-crawling mantle of ice upon a fountain of smouldering fire, crushing and grinding its brown, flinty lavas, and thus degrading and remodeling the entire mountain from summit to base.

How much denudation and degradation has been effected we have no means of determining, the porous, crumbling rocks being ill adapted for the reception and preservation of glacial inions.

The summit is now a mass of ruins, and all the finer striations have been effaced from the flanks by post-glacial weathering, while the irregularity of its lavas as regards susceptibility to erosion, and the disturbance caused by inter- and post-glacial eruptions, have obscured or obliterated those heavier characters of the glacial record found so clearly inscribed upon the granite pages of the high Sierra between latitude 36 degrees 30 minutes and 39 degrees. This much, however, is plain: that the summit of the mountain was considerably lowered, and the sides were deeply grooved and fluted while it was a center of dispersal for the glaciers of the circumjacent region. And when at length the glacial period began to draw near its close, the ice mantle was gradually melted off around the base of the mountain, and in receding and breaking up into its present fragmentary condition the irregular heaps and rings of moraine matter were stored upon its flanks on which the forests are growing. The glacial erosion of most of the Shasta lavas gives rise to detritus composed of rough subangular boulders of moderate size and porous gravel and sand, which yields freely to the transporting power of running water. Several centuries ago immense quantities of this lighter material were washed down from the higher slopes by a flood of extraordinary magnitude, caused probably by the sudden melting of the ice and snow during an eruption, giving rise to the deposition of conspicuous delta-like beds around the base. And it is upon these flood-beds of moraine soil, thus suddenly and simultaneously laid down and joined edge to edge, that the flowery chaparral is growing.

Thus, by forces seemingly antagonistic and destructive, Nature accomplishes her beneficent designs--now a flood of fire, now a flood of ice, now a flood of water; and again in the fullness of time an outburst of organic life--forest and garden, with all their wealth of fruit and flowers, the air stirred into one universal hum with rejoicing insects, a milky way of wings and petals, girdling the newborn mountain like a cloud, as if the vivifying sunbeams beating against its sides had broken into a foam of plant-bloom and bees.

But with such grand displays as Nature is making here, how grand are her reservations, bestowed only upon those who devotedly seek them!

Beneath the smooth and snowy surface the fountain fires are still aglow, to blaze forth afresh at their appointed times. The glaciers, looking so still and small at a distance, represented by the artist with a patch of white paint laid on by a single stroke of his brush, are still flowing onward, unhalting, with deep crystal currents, sculpturing the mountain with stern, resistless energy. How many caves and fountains that no eye has yet seen lie with all their fine furniture deep down in the darkness, and how many shy wild creatures are at home beneath the grateful lights and shadows of the woods, rejoicing in their fullness of perfect life!

Standing on the edge of the Strawberry Meadows in the sun-days of summer, not a foot or feather or leaf seems to stir; and the grand, towering mountain with all its inhabitants appears in rest, calm as a star. Yet how profound is the energy ever in action, and how great is the multitude of claws and teeth, wings and eyes, wide awake and at work and shining! Going into the blessed wilderness, the blood of the plants throbbing beneath the life-giving sunshine seems to be heard and felt; plant growth goes on before our eyes, and every tree and bush and flower is seen as a hive of restless industry. The deeps of the sky are mottled with singing wings of every color and tone--clouds of brilliant chrysididae dancing and swirling in joyous rhythm, golden-barred vespidae, butterflies, grating cicadas and jolly rattling grasshoppers--fairly enameling the light, and shaking all the air into music. Happy fellows they are, every one of them, blowing tiny pipe and trumpet, plodding and prancing, at work or at play.