Subject ASC0003spq
The geological magazine, or, Monthly journal of geology.
Decade 2:v.4 (1877) [Incomplete], Page 501 (1877)
Harvard University, Museum of Comparative Zoology, Ernst Mayr Library
BHL Page 32579438
Keywords
Arran rocks geology pitchstone lamination Scotland pitchstones dyke basalt cross hatch crosshatch diagram intersection line laminated structure streaky lower pitchstone dunfion curve dykes