GEOLOGY 



RECENT PROGRESS OF GEOLOGY. 



The following is an abstract of an address delivered before the 

 Geological section of the British Association, 1861, by Sir R. I. 

 Murchison ; the subject being mainly a retrospect of the progress at- 

 tained to during the last twenty years in our knowledge of the geol- 

 ogy of the older rocks. In the commencement, alluding to the recent 

 investigations respecting the antiquity of the human race, Mr. Mur- 

 chison said : 



Having carefully examined the detrital accumulations forming the 

 ancient banks of the river Somme, in France, I am as complete a 

 believer in the commixture in that ancient alluvium of the works of 

 man with the reliquiae of extinct animals as their meritorious discov- 

 erer, Perthes, or as their expounders, Prestwich, Lyell, and others. 

 I may, however, express my gratification in learning that England, 

 in several localities, is also affording proofs of similar intermixture. 



In regard to the main additions which have been made since 1842 

 to our knowledge of the older rocks in the British Isles, the following 

 statements, commencing the retrospect with the older rocks, may, 

 said Mr. Murchison, be regarded as substantially true. 



The stratified gneiss of the north-west of Scotland, and of the outer 

 Hebrides, is the fundamental rock of the British Islands, and the pre- 

 cise equivalent of the Laurentian system of Canada. The establish- 

 ment of this order is of great importance, as it gives to geology a 

 lower doctrine-line than was previously possessed. For hitherto the 

 order of the geological succession, as approved by De la Beche, Phil- 

 lips, Ramsay, Jukes, and others, admits no older sediment than the 

 Cambrian of North Wales. 



The researches in the Highlands of Scotland have, however, shown 

 that in the British Islands the older palaeozoic rocks, properly so 

 called, or those in which the first traces of life have been discovered, 

 do repose, as in the broad regions of the Laurentian Mountains of 

 Canada, upon a grand stratified crystalline foundation, in which both 

 limestone and iron ores occur subordinate to gneiss. In Scotland, 

 therefore, these earliest gneissic accumulations are now to be marked 

 on our maps by the Greek letter alpha, as preceding the Roman a, 



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