134 Rejiorts and Proceedings. 



and Natural History of the Alps, and he remarks that it may be a 

 satisfaction to future travellers if he expresses his conviction that, 

 in spite of all that has yet been done, no portion of the Alps can, in 

 a topographical and still less in a scientific sense, be said to be 

 thoroughly explored. In districts supposed to be well known, an 

 active mountaineer will constantly find scope for new expeditions ; 

 and, if he has cultivated the habit of observation, he may at the 

 same time make these subservient to tfie increase of knowledge. 



I. January 11, 187L — .Joseph Prestwich, Esq., F.E.S., President, 

 in the Chair. The following communications were read : — 1. " On 

 the older Metamorphic Rocks and Granite of Banffshire." By T. F. 

 Jamieson, Esq., F.G.S. 



The author indicated three divisions in th-e metamorphic strata of 

 Banffshire : — At bottom a great thickness of arenaceous beds, more 

 or less altered into quartz-rock, gneiss, and mica-schist ; next a 

 series of fine-grained clay-slates, in the midst of which is a bed of 

 limestones ; and then again an upper group of arenaceous strata. 

 The author stated that the arrangement of the rocks is very similar 

 to that occurring in Bute and Argyleshire. He remarked that the 

 general texture of the beds is fine-grained, and considered that they 

 were probably deposited in the depths of the sea, ofi" the mouth of a 

 great river, the deposition of the .argillaceous strata having taken 

 j)lace during a period of increased depression. The deposition of the 

 beds was said to have probably taken place after the formation of 

 the (Cambrian) Eed Sandstone and Conglomerate of the North-west 

 Highlands, or in Lower Silurian times, the river by which the sedi- 

 ment was brought down being supposed to have drained the great 

 Laurentian region to the north-west. After their accumulation the 

 author supposed that "^ glow of heat from beneath " approachesd 

 them, causing expansion and the wrinkling of the mass into folds 

 running from S.W. to N.E. The granites were considered by the 

 author to owe their origin to the fusion and recrystallization of the 

 arenaceous beds. 



Discussion. — Prof. Ramsay observed that the general section -wonderfully corre- 

 sponded with that g-iyen many years ago by Sir lioderick Murchison of the Silurian 

 and Laurentian rocks at Cape Wrath, and it seemed to him that the large views 

 originally propounded by Sir Eoderick were confirmed by the author. He was glad 

 that the metamorphic origin of granite was supported by Mr. Jamieson, as he had 

 held that view for several years, and h« was pleased to find that opinions which had 

 formerly met with so many opponents were constantly gaining acceptance. The 

 fusion of these sedimentary rocks by metamorphic action was not identical with the 

 fusion of lava, but their fluidity might be the same ; and if that were the case, there 

 could be no difficulty in accepting the possibility of the injection of such fused rocks 

 into crevices and fissures. The crumpling of the beds, however, was due to more ex- 

 tensive causes than those contemplated by the author. The proportion of igneous 

 rock injected into contorted rocks, like those of North Wales, was almost infinitesimal, 

 and the crumpling could hardly be due to mere local causes. 



Prof. Ansted Teferred to what he had observed in the north-west part of Corsica, 

 ■where about 40 feet of granite were distinctly interstratified between perfectly ua- 



