TRANSACTIONS OF THE SECTIONS. 01 



the relation between the two were established, an approximation could be made to 

 the age of certain portions of the crust of the earth. 



On the Con'iston Group of the Lalce District. 

 By Professor Hakkness, F.R.S., and Dr. H. A. NiCHOLSoif, F.G.S. 



After describing the range of the Coniston Limestone, a group of strata the 

 position and age of which had been pointed out many years ago by Prof Sedg- 

 wick, the authors referred to a mass of black shales which rests conformably on 

 these limestones, and which have yielded them a series of fossils new to the 

 horizon in which they occur. These fossils consist of eleven species of Graptolites ; 

 five of which belong to the genus Dij^ograpsus, five to Graptolites, and one to 

 Mastrites. These black shales, which are conformable to the Coniston Limestone, 

 are also conformably succeeded by the Coniston Flag group of Prof. Sedgwick, and 

 they are intercalated with the lower portion of this group. Upon the Coniston 

 flags the Coniston grits of Prof. Sedgwick occur, and the latter are also conform- 

 able to the former. 



The Coniston gTits have fossils in them, some of which have not been hitherto 

 fotmd in the Upper Silurian rocks of Great Britain ; this circumstance, taken in 

 connexion with the conformability of the whole of the Coniston series, induce the 

 authors to infer that there exists in tlie Lake country a mass of rocks which pro- 

 bably attain a thickness of nearly 7000 feet above the Bala limestone and below 

 the Upper Llandovery which have no equal representatives elsewhere in the British 

 Isles. 



On the Old Sea-cliffs and Submarine BanTcs of the Frith of Forth. 

 Bjj D. Milne Home. 



The author explained the line of old sea-clifF along both sides of the Frith of 

 Forth, which had been formed before the last change in the relative levels of sea 

 and land. He mentioned that its height at the lower parts of the estuary was 

 about 1-3 or 14 feet above the present high-water spring- tides, whilst near Stirling it 

 "was about 31 feet, and to the west about 35 or 40 feet. The autlior also specilied 

 two higher and older clitfs at heights of about 60 feet and 130 feet respectively. 

 He referred to the places where skeletons of whales and seals had been found at 

 heights varying from 18 to 23 feet above the present level of high-water mark, and 

 stated that sea-shells were found in two conditions — viz. first, in undisturbed beds 

 now 14 and 15 feet above high-v^^ater mark, where they were entire and perfect ; 

 and, 2ndly, in beaches, where they were broken. He also referred to the ancient 

 deltas, or heaps of gravel and debris at the level of the old cliff", to be seen at dif- 

 ferent places, as at Menstrie, Alva, and Tillicoidtry. He explained the origin of the 

 estuary of the Frith, by the great east and west fractm-es in the countiy adjoining 

 to the north and south. He said that in the Fife coal-field, the downcasts were 

 almost all on the south side of the fi-actures, and amounted altogether to nearly 

 2000 feet ; and in the coal-field of the Lothians, Linlithgow, aucl Stirlingshire, the 

 downcasts were, on the other hand, to the north, and even to a greater extent, thus 

 producing a trough or hollow, now filled by an arm of the sea. The rocks in this 

 hollow were covered by various drift-deposits, the oldest being boulder-clay, and, 

 over it beds of stratified clay, sand, and gravel. The gravel was generally on the 

 top, which was accounted for by the water of the estuary shallowing, whereby the 

 currents became more powerful, and thus gravel was laid down where only mud 

 or sand could be laid down before. 



The author next proceeded to describe a long ridge of gravel rimning fom* or five 

 miles through Callendar Park, by Polmont eastward towards Linlithgow. He 

 stated that its height was from 30 to 60 feet, and, judging from the materials com- 

 posing it, he considered it had been formed by sea-currents. He said that these 

 gravel ridges were very numerous in our open valleys, and that their direction or 

 course was invariably parallel with the axis or sides of the valley. Though he had 

 not seen the ridge of gravel at St. Fort, described in Dr. Chambers's paper, he could 

 not help thinking it was to be accounted for in the same way, viz. by marine cur- 



