594 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1925 



from Charles Peach's discover}'' of Cambrian fossils in northwestern 

 Sutherland. AVritin^^ in 1924, Geikie admits that this expedition 

 " was a premature attempt * * * the true structure of the High- 

 lands was far too complicated to he unraveled by desultory and 

 hasty traverses." Neither he nor Murchison had been able to doubt 

 the evidence of their eyes that in one section after another crystal- 

 line schists overlay fossiliferous Cambrian strata with what ap- 

 versy which has been laid to rest for many years, and it will suffice 

 to say that the apparent normal superposition with its far-reaching 

 consequences found no acceptance with Nicol, Heddle, Callaway, 

 Bonney, and others. Geikie, partly perhaps through loyalty to his 

 chief, for long refused to give way, and it was not till Lapworth 

 had made his exhaustive examination of the whole Durness-Erribol 

 region that he admitted his error. Once convinced, he hastened to 

 correct it. He intrusted the surveying of the region to B. N. Peach 

 and J. Home, who with their colleagues produced what was prob- 

 ably the most detailed and masterly study of overthrusting on a 

 great scale that had ever been made. 



The succession of strata in the Moffat and Girvan districts was 

 determined in somewhat similar stages. There also it had been 

 masked by earth movements. Faults and excessive plication had 

 repeated the same beds over and over again, and it was only by 

 detailed surveying and intensive study of the fossils that Lapworth 

 unraveled the tangle. His predecessors had been content to leave 

 as one group a series of strata varying extraordinarily in thickness 

 and petrological character, and containing an admixture of fossils 

 that were elsewhere characteristic of distinct formations. He re- 

 duced this enigmatical " group " to an orderly sequence, each mem- 

 ber of which was distinct in character and fossils, and established 

 correlation with other parts of the kingdom. It is interesting to 

 see how closely these Highland controversies were paralleled in the 

 United States. There the succession of the same rocks was in 

 question, the same difficulties in determining it were encountered, 

 and the same mistakes were made. The " Taconic System," founded 

 in 1842, formed the subject of controversy for upwards of 60 years, 

 until it was finally proved to consist of Cambrian and Silurian 

 strata folded and faulted together in no sort of chronological 

 order. That the first geologists to encounter problems so calculated 

 to deceive should have failed to master them need cause no surprise. 

 Rather should our sympathies be extended to pioneers who were 

 faced with the impossible task of interpreting dislocations, the 

 existence of which could be ascertained only by prolonged and 

 detailed mapping. But we may admit that our sympathy might 



