Mr. J. W. Judd on the Secondary Rocks of Scotland, 545 



masses of igneous rocks, in part at least of subaqueous origin. These 

 exhibit a very close similarity in penological character to the lavas 

 of Lorn, and are shown, by the interbedded and contemporaneous 

 fossiliferous sediments associated with them, to range in age from 

 the Lower Old Red Sandstone to the Lower Carboniferous. 



Along the whole line of the Grampian Mountains we find a number 

 of granitic masses connected with a wonderfully complicated series 

 of veins and dykes of rocks of similar composition. These igneous 

 intrusions, which disturb and metamorphose the surrounding strata, 

 are evidently, as shown by Murchison and Geikie, of far later date 

 than the Lower Silurian, but are earlier than the Secondary strata. 



Concluding, as we cannot avoid doing, that these igneous intru- 

 sions and the subaerial and subaqueous lavas of similar composition 

 were all formed during the Newer Palaeozoic periods, we are led to 

 the presumption of their probable former connexion with one 

 another. By the phenomena presented at a number of interesting 

 points, such as Ben Nevis and Glencoe, where the granitic rocks 

 and the lavas are so associated with one another and with masses of 

 volcanic agglomerate as to demonstrate the identity of their origin 

 with that of the similar masses of Tertiary age in the Hebrides, this 

 presumption is converted into certainty. The Newer Palaeozoic 

 period of volcanic eruption terminated, like that of the Tertiary 

 epoch, by a grand development of "puys" during the Carboniferous 

 and Permian periods. Of these, the celebrated Arthur's Seat, near 

 Edinburgh, and many similar cases in Fife and the Lothians may 

 be cited as examples. 



Conclusion. — It appears that during the Newer Palaeozoic and the 

 Tertiary periods, the north-western parts of the British archipelago 

 were the scene of displays of volcanic activity upon the grandest 

 scale. During either of these, the eruption of felspathic lavas &c. 

 preceded, as a whole, that of the basaltic ; and, in both, the volcanic 

 action was brought to a close by the formation of " puys/' The 

 range of Newer-Palaeozoic volcanoes arose along a line striking N.E. 

 and S.W., that of the Tertiary volcanoes along one striking from 

 N. to S.; and each appears to have been connected with a great 

 system of subterranean disturbance. It is an interesting circum- 

 stance that the epochs of maximum volcanic activity, the Old Red 

 Sandstone and the Miocene, appear to have been coincident with 

 those which, as shown by Prof. Ramsay, were characterized by the 

 greatest extent of continental land in the area. 



The Secondary strata were deposited in the interval between the 

 two epochs of volcanic activity ; and the features which they present 

 have been largely influenced by this circumstance. Apart from this 

 consideration, however, the volcanic rocks of the Highlands are of 

 the highest interest to the geologist, both from their enabling him 

 to decipher to so great an extent the " geological records " of the 

 district, and from the light which they throw upon some of the 

 obscurest problems of Physical Geology. 



3. " Remarks on Fossils from Oberburg, Styria." Bv A. W. 

 Waters, Esq., F.G.S. 



The author noticed the limited occurrence of Eocene deposits ia 

 Phil. Mag. S. 4. No. 321. SttppL Vol. 48. 2 N 



