Shamrock Proppants shuts down indefinitely in mid-Missouri

Operations have been shut down at a central Missouri plant that makes materials used in fracking.

The Shamrock Proppant plant in Mexico shut down indefinitely Thursday in the wake of the recent downturn in oil prices and a pullback in fracking operations.

Proppants are a treated sand or ceramic gravel mixture used in the fracking industry to open cracks in deep-rock formations to help release oil.

The Energy Information Administration says U.S. oil production decreased by 120,000 barrels per day in September from August.