Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/89

Rh turns westward again as the north leg of the main Tuscarora synclinal to Port Royal. Along the basin there are in places as high as 60′ of No. VI exposed ; but the individual beds are never over 3′ or 4′ thick, and the good burning portion of the series will not aggregate over 40′ in thickness.

West of the Juniata the outcrop of No. VI on the north side of the Tuscarora synclinal, shows but a single line, passing through McCoysville and back of Peru Mills to Huntingdon county.

The best exposures are at McCoysville and Peru Mills, at both of which places the limestone beds have been quarried. At McCoysville No. VI shows about 150′ thick, including the upper shaly members, the massive pure limestone at the bottom occurring in a series of thin beds about 40′ thick. At Peru Mills the exposure measures about 50′, with but few large beds.

The south outcrop of limestone in Juniata county forming the south leg of the Tuscarora synclinal, extends from the base of Turkey ridge, in front of the Tuscarora mountain gap in Delaware township, through Thompsontown to Mexico on the Juniata. There are few good exposures here. At the Hamilton quarries all the good lime is quarried from 60′ of measures, none of the individual beds being more than 3′ thick.

About the same thickness is exposed in Benner’s quarry, 1½ miles further west, and on the river below Mexico, where, however, the upper shaly limestone increase the section by 80′. West of the river the limestone belt makes nearly a straight line past Pleasant View to Bealetown, where it makes a synclinal loop, and at Allen’s quarry shows about 60′ thick, dipping N. 30° W. 35°. The stone is evenly bedded and has a sub-crystalline structure, greyish-blue in color, and rather silicious at the base. The upper portion is fossiliferous, the good limestone being about 40′ thick.

West from here to Huntingdon county the Tuscarora creek partially cuts out the section of No. VI, which has evidently decreased in thickness, so that a complete section would scarcely show more than 150′-200′ of measures.