Document Type


Publication Date

Spring 2-5-1898


About two and one-half miles southwest of the University of Colorado, and slightly south of the fortieth parallel, a large outcrop of volcanic rock cuts the granite. Specimens of the same material have been brought to the University Laboratory from as far west as Magnolia, and outcroppings are reported at various intermediate places. This would give the dike a general direction of east and west, and a length, as far as known, of some six or eight miles. Although the material examined was from the most easterly known outcrop, it seems better to refer the whole dike to the Magnolia district.