ReporU and Proceedings — Geological Societg of London. 283 



and North Curry, in Somerset. Some of the lowest beds may be 

 called ' siltstones ' ; they were originally silty muds. The author 

 concludes that the boring did not reach the beds which near Sidmouth 

 form a passage from the Keuper Marls to the Keuper Sandstones, 

 and that the Keuper Marls proved by the boring are at least 

 1130 feet, and may amount to 1200 feet in thickness. 



IL— April 16th, 1902.— Professor Charles Lap worth, LL.D., F.R.S., 

 President, in the Chair. The following communications were 

 read : — 



1. " The Carlisle Earthquakes of July 9th and 11th, 1901." By 

 Charles Davison, Sc.D., F.G.S. 



The shocks were at least four in number, and there are single 

 records of four other shocks. The isoseismal 5 of the first and 

 principal shock is very nearly a circle 29 miles in diameter, with 

 its centre 7 miles south-south-west of Carlisle, and is excentric 

 with regard to the isoseismal 4. The continuity of the shock over 

 a band extending from Carlisle to Coniston implies a corresponding 

 continuity in the focus. The investigation of the earthquakes has 

 led to the recognition of a deep-seated fault, the average direction 

 of which is N. 5° E. and S. 5° W., and the hade throughout is to 

 the east. In the surface-rocks there is no sign whatever of such 

 a structure. The movements along the fault were somewhat 

 peculiar. In the first shock the focus was of considerable length, 

 and consisted of two principal portions, the centres of which were 

 about 23 miles apart, connected by a region wherein the slipping 

 was continuous throughout, and much less in amount. The northern 

 part of the focus was smaller than the other, but was marked by 

 a much stronger impulse. The third slip was complementary to 

 the first, for it appears to have occupied the whole of the region 

 between the two principal portions of the first focus, and to have 

 been greatest near the centre of that region and to have gradually 

 diminished towards both ends. 



2, "The Inverness Earthquake of September 18th, 1901, and its 

 Accessory Shocks." By Charles Davison, Sc.D., F.G.S. 



Since the Connie earthquake of 1839, which Avas followed by 

 330 tremors and earth-sounds within little more than two years, 

 no British earthquake has been attended by so many accessory 

 shocks as this one. The unusual intensity of the earthquake, its 

 apparent connection with the great northern boundar}' fault of the 

 Highlands, and the possibility of tracing oscillations in successive 

 centres of disturbance along the fault surface, combined in rendering 

 a detailed investigation desirable. With a few exceptions, the 

 earthquakes originated beneath the district lying between Inverness 

 and the north-eastern end of Loch Ness. The mean direction of 

 the fault, which follows the line of the Great Glen, is N. 35° E. and 

 S. 35° W., and its hade is to the south-east. The isoseismal 8 contains 

 67 square miles, and its centre is about 1|- miles east-north-east 

 of Dochgarroch and f mile south-east of the fault-line. The 

 correspondence between the position of the great boundary fault 



