Post 01240
Created:
Modified:
The attention of hunters and prospectors, who see so much in their wild journeys, is seldom attracted by moraines, however regular and artificial-looking; or rocks, however boldly sculptured; or cañons, however deep and sheer-walled. But when they come to these pavements, they go down on their knees and rub their hands admiringly on the glistening surface, and try hard to account for its mysterious smoothness and brightness. They may have seen the winter avalanches come down the mountains, through the woods, sweeping away the trees and scouring the ground; but they conclude that this cannot be the work of avalanches, because the striæ show that the agent, whatever it was, flowed along and around and over the top of high ridges and domes, and also filled the deep cañons. Neither can they see how water could be the agent, for the strange polish is found thousands of feet above the reach of any conceivable flood. Only the winds seem capable of moving over the face of the country in the directions indicated by the lines and grooves.
The pavements are particularly fine around Lake Tenaya, and have suggested the Indian name Py-we-ack, the Lake of the Shining Rocks. Indians seldom trouble themselves with geological questions, but a Mono Indian once came to me and asked if I could tell him what made the rocks so smooth at Tenaya. Even dogs and horses, on their first journeys into this region, study geology to the extent of gazing wonderingly at the strange brightness of the ground, and pawing it and smelling it, as if afraid of falling or sinking.
In the production of this admirable hard finish, the glaciers in many places exerted a pressure of more than a hundred tons to the square foot, planing down granite, slate, and quartz alike, showing their structure, and making beautiful mosaics where large feldspar crystals form the greater part of the rock. On such pavements the sunshine is at times dazzling, as if the surface were of burnished silver.