The Mancos Shale is an important source of natural gas in the western United States. This rock
unit formed during the Late Cretaceous (100 to 66 million years ago) from sediment deposited
in a vast seaway (the Cretaceous Interior Seaway) that spanned from the Gulf of Mexico to
Canada. Why does shale form in deep ocean environments? What other facies (specific
features) may help us to determine the shale is marine?

It’s worth repeating, over and over again: Wash your hands. Wet your hands with clean running water and then lather them with soap; don’t miss the backs of your hands, between your fingers and under your nails. Make sure to scrub for at least 20 seconds (or about the time it takes to sing “Happy Birthday” twice), and dry them with a clean towel or let them air dry. Alcohol-based hand sanitizers, which should be rubbed in for about 20 seconds, can also work, but the gel must contain at least 60% alcohol.

heat from the core of the earth causes convection currents to occur in the mantle. these currents slowly move the crust around.