Subject ASC0003sfa
The geological magazine, or, Monthly journal of geology.
[Decade 1]:v. 8 (1871), Page 206 (1871)
Harvard University, Museum of Comparative Zoology, Ernst Mayr Library
BHL Page 32578491
Keywords
valley of denudation geological observations Valley of Denudation coal measures table diagram valley denudation erosion permian rocks older coal-measures coal sections rock permian