Displaying 11851 items
Filter

Date

Show more

Language

Basalt dike (?)
Basalt dike (?)
Close folding, Catskill strata
Close folding, Catskill strata
Dripstone in Hi-wa-may Cavern
Entrance Hi-wa-may Cavern
Faults in Martinsburg shale quarry near Bethel
Glory Troops trained here
Looking over Huntingdon (reformatory at right)
Report of the Department of Mines of Pennsylvania Pt. I Anthracite … (1906)
Report of the Department of Mines of Pennsylvania Pt. I Anthracite … (1907)
Report of the Department of Mines of Pennsylvania Pt. I Anthracite … (1908)
Report of the Department of Mines of Pennsylvania Pt. I Anthracite … (1909)
Report of the Department of Mines of Pennsylvania Pt. I Anthracite … (1910)
Report of the Department of Mines of Pennsylvania Pt. I Anthracite … (1912)
Report of the Department of Mines of Pennsylvania Pt. I Anthracite … (1915)
Report of the Department of Mines of Pennsylvania Pt. I Anthracite … (1915)
Report of the Department of Mines of Pennsylvania Pt. I Anthracite … (1916)
Report of the Department of Mines of Pennsylvania Pt. I Anthracite … (1917)
Rock structure