148 Professor J. W. Gregory — Deep Bore at Seascale. 



St. Eees Head. That the whole of the 3,180 feet of strata belongs 

 to the St. Bees Sandstone is, however, doubtful. One of the most 

 characteristic features of the St. Bees Sandstone is its alternation of 

 posts of red sandstone with beds of shale. Between the depths of 

 2,072 to 3,200 feet the rocks passed through in the Seascale bore 

 have this character, for they consist of twenty beds of shale and 

 shale partings and twenty beds of sandstone. Two core samples, 

 which I owe to the kindness of Mr. Fleming Smith, one from the top 

 and the other from the bottom of this lower part of the section, are 

 both similar to the St. Bees Sandstone. The upper sample is a typical 

 St. Bees Sandstone with partings of abundant white mica. The 

 precise depth of this sample is not known. Mr. Fleming Smith tells 

 me that it came from between the depths of 1,940 and 2,344 feet; 

 and out of this 404 feet the top 132 feet lies within the thick upper 

 sandstone, and the lower 272 feet belongs to the alternate sandstone- 

 shale series. Judging from the aspect of the rock it probably came 

 from one of the sandstones of the lower 272 feet belonging to the 

 sandstone-shale series. 



The specimen from the depth of 3,200 feet I examined micro- 

 scopically on the chance of recognizing some material which would 

 indicate the source of the constituents. It is a felspatliic grit, similar 

 to much St. Bees Sandstone ; the section contains numerous rounded 

 grains which have probably been derived from the Penrith Sandstone. 

 As the section shows tourmaline and kyanite, Mr. G. W. Tyrrell 

 kindly extracted some of the heavy residue; he has identified in it 

 abundant zircon, tourmaline, magnetite, and ilmenite, many grains 

 of andalusite, some of which are well rounded, and also particles of 

 staurolite, kyanite, and possibly of cordierite and anatase. 



In its microscopic characters the rock agrees with the St. Bees 

 Sandstone ; and this list of accessory constituents suggests that the 

 material was derived from south-western Scotland rather than from 

 the Lake District. The rocks on the margin of the Galloway Granite 

 would have supplied the accessory minerals. 



Further doubt as to whether all the beds belong to the St. Bees 

 Sandstone is suggested by their great thickness. Goodchild, in one 

 of the latest summaries of the geology of Cumberland, estimated the 

 maximum thickness of the St. Bees Sandstone as 1.800 feet ("Geology" 

 in The Victoria History of the County of Cumierland, vol. i, p. 36, 

 1901) ; and though it is possible that the formation may have suddenly 

 increased to 3,200 feet, as by the filling up of an ancient valley, any 

 such thickness of the St. Bees Sandstone was not expected when the 

 bore was undertaken, and it justifies doubt as to the identification. 



That the upper part of the Seascale bore was not in the St. Bees 

 Sandstone is suggested by the great thickness of continuous sandstone, 

 which, according to the bore record, amounts to 2,047 feet of sand- 

 stone interrupted by only a 5 foot seam of red shale. I know of no 

 such occurrence in- the St. Bees Sandstone. It is unfortunate that 

 no cores from this upper Seascale Sandstone are available. Mr. Fleming 

 Smith tells me that the cores have been dispersed, and if any 

 specimens could be found there would be no evidence as to their 

 depth. The only evidence available from the bore is the record of 



