Shale is a sedimentary rock made up of tiny grains of silica, clay and other minerals. Many types of rock have few physical ...

The striations show sedimentary layers; the darker the color of a layer, the higher its oil shale content. Credit: US Geological Survey What Is Oil Shale? Caption: Oil shale: The rock that burns.

1 Although nobody told Mr. Callahan until it was too late, the dark-hued shale rocks found in pockets along the Western Slope were oil shale. Often referred to as the rock that burns, oil shale boasts ...

A shallow sea advances and retreats several times during this period, leaving behind the layers named Kaibab Limestone, Toroweap Formation, and Hermit Shale ... the rock reveals that its color ...