Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/90

62 F³.

Various names have been given by different geologists in their different districts of Pennsylvania to the measures underlying massive beds of the Lewistown (Lower Helderberg) Limestone No. VI.

Pof. Rogers included in his Sealent and Surgent series all the rocks between the No. VI limestone, and the top of the white Medina sandstone No. IVc, which forms the crests of so many of the mountain ridges of thed istrictthe district [sic]. The Scalent series he made triple:&emsp;1. The Scalent lime- stone on top, corresponding to the Water Lime formation of New York;&emsp;2. The Scalent grey marls, and,&emsp;3. The Scalent variegated marls, both of which he correlated with the Onondaga Salt group of New York.

The Surgent series, underlying the Scalent, he divided as follows, from above downward:

Mr. Dewees, in Report F, further subdivided these groups, and in the measured sections by Messrs. Ashburner and Billin, given in that report at Lewistown, MeVeytown and Mt. Union, the following nomenclature was adopted: