20G SEE— FURTHER RESEARCHES ON [April 24. 



veloped or are now developing, and in general the faults run along 

 the sea coasts and into the sea, where mountain fonnation is in 

 progress. Thus it is clear that faults arise from the stresses and 

 movements of the crust produced by earthquakes and mountain 

 formation, and therefore from the secular leakage of the ocean 

 bottoms. 



Sometimes the faults move but little, at other times they give 

 rise to conspicuous changes of level ; and where vast down-throws or 

 uplifts have occurred certain types of mountains arise from normal 

 faulting. The more horizontal movements of faults arise mainly 

 in the trenches along the sea coasts, which produce the folding seen 

 in mountain chains. The vertical movements are more general, and 

 are especially conspicuous in elevated plateaus, like those of our 

 western states. 



In his " Report on the Geolog}' of the High Plateaus of Utah," 

 Washington, 1880, Major Button gives a description of some of the 

 most magnificent faults in the world. On page 45 he indicates the 

 dependence of these faults on the ancient shore line of the Eocene 

 lake, thus : 



" It yet remains to speak of another interesting relation of the later 

 system of faults. They have throughout preserved a remarkable and per- 

 sistent parallelism to the old shore line of the Eocene lake, following the 

 broader features of its trend in a striking manner. The cause of this rela- 

 tion is to me quite inexplicable, so much so, that I am utterly at a loss to 

 think of any subsidiary facts which may be mentioned in connection with it 

 and which can throw light upon it." 



What puzzled Major Button most was the raising of the area of 

 the lake ; but as the whole region was uplifted by the sea in later 

 times this phenomenon was in no way remarkable. The rocks in such 

 disturbed regions have been broken and folded into a series of 

 troughs and arches or thrown into domes and basins, and probably 

 no two adjacent areas retained their relative levels throughout. His 

 observation, however, confirms the present theory that faulting is 

 generally parallel to the ancient sea shore, and therefore produced 

 originally by the oceans. 



The conspicuous character of the vertical movement of the crust 

 blocks in the region of the Great Basin led several American geolo- 

 gists to suggest that vertical forces had operated in the uplift of 



