1. Subsurface structure of the plateau region of north-central and western Pennsylvania on top of the Oriskany formation [cartographic material] Yale Public content 1962. 2018-04-18T19:37:50Z. 2018-09-05T19:43:34Z. Cate, Addison S. Pennsylvania Bureau of Topographic and Geologic Survey. English. cartographic image. Public. Pennsylvania and Pennsylvania.