Page:Popular Science Monthly Volume 7.djvu/407

Rh level of the river. Now that bed is gone from the mountains, yet it can be seen turned up on edge against the flanks of the mountains, dipping under the beds of rocks found still farther out from the range. Follow it down, and doubtless we could trace it to a depth much below the level of the sea. While the folds were forming, the up-turned flexures were cut down, and the troughs in the down-turned flexures were filled up, and we have more than 8,000 feet of these later sediments to the north of the Uinta Mountains.



It will thus be seen that the upheaval was not marked by a great convulsion, for the lifting of the rocks was so slow that the rains removed the sandstones almost as fast as they came up. The mountains were not thrust up as peaks, but a great block was slowly lifted, and from this the mountains were carved by the clouds—patient artists, who take what time may be necessary for their work.

We speak of mountains forming clouds about their tops: the clouds have formed the mountains. Lilt a district of granite, or marble, into their region, and they gather about it, and hurl their storms against it, beating the rocks into sands, and then they carry them out into the sea, carving out cañons, gulches, and valleys, and leaving plateaus and mountains embossed on the surface.

Instead of having a rounded billow, we have an irregular table, with beds dipping to the north, on the north side of the axis, and to the south, on the south side, and in passing over the truncated fold we pass over their upturned edges.