Yorkshire Boulder Committee : Fourteenth Years Work. 363 



Cragg Vale stream. On the south it abuts against the 

 rising- valley sides. 330 ft. to 360 ft. O.D. 



Two sections were cut for the Yorkshire Geological and 

 Polytechnic Society in the easterly slope of the terrace. 



A great number of rounded boulders were dug - out principally 

 of quite local rocks, but 74 were picked out and were found on 

 examination to be as follow s : 



Galliard or ganister 



18 



Granophyres 



18 



Andesites 



1 0 



Rhyolites 



8 



Silurian grits 



7 



Vein quartz ... ... 



5 



Eskdale granite... 



2 



V olcanic ash 



2 



Carboniferous sandstone 



2 



Chert ... 



1 



Quartz felsite ... ... ... 



1 





74 



They ranged in size from about 6 in. x 4 in. x 3 in. to pebbles 

 ij4 in. long", were embedded in a gravelly and sandy matrix, 

 and were distributed equally throughout the sections. 



Mr. J. W. Stather, F.G.S., furnishes the substance of a 

 paper 1 read before the British Association at Bradford, which 

 forms a valuable summary of the work done by the members of 

 the Hull Geological Society and its general results to date. 



The members have examined and tabulated upwards of 3,500 

 boulders of 12 inches and upwards in diameter. 



But besides the larger boulders attention has been paid to 

 the smaller stones of the drift, w hich have also yielded results of 

 much interest. 



With regard to the larger boulders (lists of which have 

 been published in the reports of the Yorkshire Boulder Com- 

 mittee and of the British Association Committee) it has been 

 sought to discover the proportion of rocks from distant 

 Sources, after the elimination of the secondary rocks of local 

 derivation. 



''The Source and Distribution of Far-Travelled Boulders of East 

 Yorkshire.' 

 [900 December i. 



