196 prof. t. t. groom on the geological [feb. i9oo, 



Discussion. 



Sir Archibald Geikie, in response to a call from the President, 

 remarked that, having no personal acquaintance with the ground 

 described in the paper, he hardly felt himself competent to oner any 

 criticism. He had listened, as they all had done, with great 

 admiration of the skill with which the complicated structure of a 

 hill-range had been dissected in the field and expounded by the 

 Author. To a geologist familiar more particularly with the types 

 of dislocation presented by the older rocks, it could not but be of 

 extreme interest to find these types repeated, even in minute detail, 

 among rocks so late as the Coal Measures. The account given in 

 the paper of the faults of the region, taken in connexion with the 

 subject of the previous paper by Dr. Davison, 1 recalled to the 

 speaker's memory an opinion expressed to him many years ago by 

 the late Mr. liichard Gibbs, who, as Fossil-collector to the Geological 

 Survey, proved himself to be a shrewd observer, and as a 

 native of Gloucestershire had been familiar with the Malvern Hills 

 from boyhood. He believed that there is reason to think that the 

 great post-Triassic fault along the eastern side of that chain of hills 

 is still moving. Sir Archibald had never been able to obtain any 

 confirmation of this opinion, but it was held so positively by so 

 good a geologist that he had often wished to know whether any 

 precise watch had been kept along the line of the fault, with the 

 view of detecting a possible movement. He would like to ask 

 the Author whether he had looked into the question, and particularly 

 whether any examination of the ground had been made after the 

 last earthquake that affected it. 



Mr. Wickham King supported the Author's conclusions that there 

 were great earth-movements in the Carboniferous period resulting 

 in the overthrust of Archaean and other rocks to the west, and said 

 that his own work in the Silurian ground agreed with much of that so 

 graphically described by the Author. He was, however, unable to 

 agree with some of the conclusions relating to the so- called ' Permian' 

 (HafBeld) breccias and the Trias. The sandy nature of these Haffield 

 breccias agreed more with the sandy Bunter and Keuper breccias 

 existing on the northern flanks of the Abberley Hills, than with the 

 marly breccias interstratifiedwith the Enville Permians. There is no 

 known stratigraphical evidence below these Haffield breccias to prove 

 their age ; they contain no fossils ; and though at places there is some 

 appearance of an upward transition of these breccias into Triassic 

 Sandstones, yet the earth-movements have affected the breccias 

 and sandstones so much that decisive proof is difficult to obtain. 

 We should therefore adopt the name given to them by Prof. Phillips 

 of • Haffield Breccias,' until further proofs are announced. He 

 agreed with the views repeatedly expressed by Prof. Lapworth, 

 that in the Carbo-Triassic periods highlands existed south of the 

 Lickey and east of the Malverns, that much of the talus derived 



1 ' On the Cornish Earthquakes of March 29th to April 2nd, 1898,' pp. 1-7 of 

 this volume. 



