Page:Popular Science Monthly Volume 79.djvu/425

This page has been proofread, but needs to be validated.

PSM V79 D425 Sill of igneous rock in contact with a coal seam.pngA Sill of Igneous Rock in contact with a Seam of Coal. Some of the coal has been converted into coke as a result of the intrusion. South end of Carbon Mountain. flows from beneath the margin of the glacier; Stillwater and Shepherd Creeks drain Lakes Kushtaka and Charlotte, respectively. Both of these lakes are of glacial origin.

The precipitation of the region is probably in excess of 130 inches annually. The snow fall is very heavy. Above an elevation of 1,500 feet considerable snow is present even during the summer months.

The climate is not severe, the coldest weather recorded being 2° F. above zero. PSM V79 D425 Purdy claim tunnel entrance west of shepherd creek.pngEntrance to a Tunnel on the Purdy Claim West of Shepherd Creek. The average winter temperature is about freezing point; the average summer temperature between 50° and 55° F.

The slopes are usually timbered with spruce and hemlock to an elevation of more than 1,000 feet.

The Geology of the Region

The chief rocks of the coal field consist of indurated sediments of Tertiary age and unconsolidated stream deposits, abandoned beaches and morainal material of Quaternary age. Associated with the Tertiary