Post-Gazette: If we could take a tiny glass elevator down the trajectory of a Marcellus Shale well, we would see slabs of coal, sandstone, shale and siltstone alternating and colliding with one another for thousands of feet until we finally reach the target rock.
Today, half a dozen local oil and gas companies are forgoing the full ride. They're getting off the elevator halfway down, before the Elk Sandstone formation that separates the conventional oil and gas reservoirs from the deeper, unconventional plays...