Geological Society of London. 139 



Geological Society of London. — I. — January 21, 1874. — Prof. P. 

 Martin Duncan, F.E.S., Vice-President, in the Chair. — The following 

 communications were read : — 



1. Extract of a Despatch from Mr. Williams, H.M.'s Consul at 

 Samoa, dated Sydney, October 28, 1873. Communicated by H.M.'s 

 Secretary of State for Foreign Affairs. 



"The afternoon before I left [Samoa], samples of gold in quartz 

 were put into my hands, found by three Englishmen in a valley 

 about three miles from the port of Apia, but not having visited the 

 spot I cannot vouch for the discovery, but I have every reason to 

 believe that the gold is there ; and I have had the samples assayed 

 here, and the yield is at the rate of 3000 ozs. to the ton." 



2. "The Secondary Eocks of Scotland. — Second Paper. On the 

 Ancient Volcanos of the Highlands and their Eelatious to the 

 Mesozoic Strata." By J. W. Judd, Esq., F.G.S.' 



Discussion. — Mr. Campbell thanked the author for having taught him so much 

 concerning a district in which he had been born and bred. 



Mr. D. Forbes was gratified to find the subject of the igneous rocks of Britain 

 taken up in so able a manner, and the subject not left entirely to continental 

 geologists. The author was fortunate in the fact that he had occupied the same 

 ground as that which had already been explored by Prof. Zirkel, whose work had 

 been thus supplemented. He agreed with the author in regarding Volcanic and 

 Plutonic rocks, from granite down to the most recent lavas, as of one and the 

 same origin. He suggested a doubt whether the older granites belonged to so 

 recent a period as that assigned to them by the author. 



Prof. Maskelyne considered that this paper would go far towards settling the 

 question between one half of the petrologists of the present time and the other 

 half. He accepted the author's view as to the Tertiary origin of the granite ex- 

 tending over so large an extent of country, and considered that the views of 

 Richthofen were thus substantiated, and that the present paper would form a 

 starting-point in this field of geology. It showed, moreover, the necessity of 

 combining the observations of the geologist in the field with those of the miner- 

 alogist in his laboratory. 



Mr. Seeley observed on the importance of this paper as fui'nishing lines of 

 departure for investigating the early physical history of the earth. He had 

 ascertained that the old lines of volcanic activity corresponded with the agonic 

 lines of magnetism, and the paper afforded data which would assist in drawing 

 conclusions as to the changes in the position of the earth's axis by a comparison 

 of these lines with those of the magnetic currents. 



Mr. W. W. Smyth congratulated himself on again hearing of intrusive granitic 

 dykes such as recalled the earlier days of the Society, and tended to dispel some 

 accepted ideas as to metamorphism. He adduced the recent deposits of Etna and 

 Vesuvius in illustration of the specimens exhibited by the author. 



Mr. Blanford suggested that there might be in this case only one form of the 

 protrusion of granite. When the gradual passage from stratified rocks into granite 

 could be traced, there could be little doubt of its origin ; and even here the granite 

 might be only the result of a very complete metamorphism. He agreed with the 

 author as to the probability of the great horizontal outflows of basalt being sub- 

 aerial, and not subaqueous, and instanced analogous examples in India. 



Mr. Tiddeman, referring to the great length of time alluded to by the author, 

 as represented in the volcanic rocks of Scotland, wished to call attention to the 

 rocks in the neighbourhood of Seuir-na-Gillean in Skye, which consisted partly of 

 basaltic lavas of Miocene age. These appeared to be tilted by the syenite of 

 Marscou, etc. , and upon both rested unconformably a great thickness of hypersthene. 



^ An abstract of this paper appeared in the February Number at page 68. 



