CAMBRIAN AND PRE-CAMBRIAN.—The oldest strata penetrated by the
drill are those in the bottom of the 3200-foot William Hoover
No. 1 well one-fourth mile south of Nicholasville in Jessamine
County. The well is reported by Miller (1921) to have penetrated
2880 feet to the base of the Knox dolomite and to have finished
in 320 feet of sandstone and shale referred to the Cambrian
Nolichucky formation on the basis of the identification of
trilobite fragments by Ulrich. It is located near the crest of
the Jessamine dome and was begun in the Hermitage formation. No
wells have penetrated to the Pre-Cambrian, and the above
mentioned one is the only well reaching the Cambrian. A number
of deep tests in Ohio, Indiana, and Illinois have reached the
Pre-Cambrian, several of them penetrating igneous rock (Wasson,
1932; Condit, 1913; Logan, 1925, 1926). These include: (a) the
Findlay, Ohio, wells, which penetrated a red granite gneiss at
about 2800 feet, (b) the Ohio Oil Company's Burns No. 1 at
Sandusky, Ohio, (c) the Greent