00954cam a22002531 4500 gs 39000361 DLC 20260227111345.0 780817s1939 pauab b 000 0 eng c gs 39000361 (OCoLC)4149251 U.S. Geol. Survey. Library PU DLC QE158.P55 L42 Leighton, Henry, 1884- Guidebook to the geology about Pittsburgh, by Henry Leighton. Harrisburg, Pa., Department of internal affairs, Topographic and geologic survey, 1939. 35 p. illus., map, tables. 23 cm. Bulletin G, 17 At head of title: Pennsylvania Geological survey, Fourth series. On cover: Commonwealth of Pennsylvania. Department of internal affairs. "Selected bibliography": p. 34-35. Pittsburgh (Pa.) Guidebooks. Geology Pennsylvania Pittsburgh Region. 27595 27595