A groundswell of interest in oil and gas production from shales is transforming the domestic industry. It's a surprising development for such an unassuming rock. After all, shales are the epitome of quiet-formed during eons of slow and steady deposition, undisturbed by great gushes of sediments from rivers or the busy, colorful lives of reef dwellers.

Shales are the tortoises among the world's hydrocarbon reservoirs, often under-appreciated and, until recently, often overlooked. But the rousing success of the Barnett shale play in the Fort Worth Basin, and the emergence of ...