rock oil

But by fracking the rock, oil flowed from the shale.

From The Wall Street Journal ● Apr. 8, 2014

There are likewise springs of rock oil or bitumen.

From A General History and Collection of Voyages and Travels — Volume 02 Arranged in Systematic Order: Forming a Complete History of the Origin and Progress of Navigation, Discovery, and Commerce, by Sea and Land, from the Earliest Ages to the Present Time by Robert Kerr

The gold mines of California and of Australia are too well known to require mention; but we must not forget the rock oil, concealed for ages in the North American continent.

From The Mines and its Wonders by William Henry Giles Kingston

No. On all bearings the same oil, but on mainspring a rock oil.

From Friction, Lubrication and the Lubricants in Horology by William T. Lewis

It has in one part a spring of petroleum or rock oil, and one of its mountains is a volcano.

From A General History and Collection of Voyages and Travels — Volume 06 Arranged in Systematic Order: Forming a Complete History of the Origin and Progress of Navigation, Discovery, and Commerce, by Sea and Land, from the Earliest Ages to the Present Time by Robert Kerr