This dike extends a few miles from the West Spanish Peak, and dates back some 25-30 million years.

The hot magma forced its way up at enormous pressure, taking advantage of every available fracture.
As it rose it carried fragments of the layers it passed through, melting those it could, and integrating the stuff that wouldn't melt.

Some of the rocks embedded are from the continental craton, a layer of Precambrian rocks presently located two miles below the surface.
Those rocks are 1.6 to 1.7 billion years old and are among the first permanent rocks in North America.