Sill containing mantle xenoliths, Elephant Butte, New Mexico
This interesting basalt unit (dark layer) is about 1 meter thick. It contains abundant xenoliths of different lithologies. The most common are (mantle) lherzolites, and (crustal) granulites. The basalt cuts across the apparent bedding in the surrounding country rock, but has been described as a flow in some literature. Pocket knife for scale. See GeoDIL-2978 (click below) for a wider angle view.
