268 



GEOLOGICAL NOTES ON THE 

 MIDDLET0N=1N=TEESDALE DISTRICT. 



By J. J. BURTON, F.G.S. 



The three principal objects of investigation by the Geological 

 section of the Yorkshire Naturalists' Union at its recent meeting 

 at Midclleton-in-Teesdale were : — 



{a) The Limestone sections as compared with those of 

 the Ingleborough district. 



{b) The Great Whin Sill and its effect upon the strata 

 above and below. 



(c) Glacial action and the occurrence of erratics. 

 Time did not permit of going over the area where the sec- 

 tions of limestone could be examined in the order in which they 

 were laid down, but during the three days excursions a large 

 number of exposed sections in different localities w^ere visited, 

 which enabled the members to get a good idea of their sequence 

 and of the important dislocations which have occurred in the 

 area. 



Going up Hudeshope Beck, line sections of the Great or 

 Main Limestone were seen, together with considerable thick- 

 nesses of black shales and grits. These were not again observed 

 until visiting the Lune Valley, when they were found in the bed 

 of the stream some distance up, beyond the dam of the Grass- 

 holm reservoir, and also on the south bank of the river. At this 

 point they have an extremely sharp dip nearly due south. 

 In this exposure a very fine prolific band of cup corals and 

 Brachiopods was noticed, and specimens were taken for identi- 

 fication. 



On the south side of the Tees, and below the Whin Sill, an 

 exposure of the Jew (or Hardraw) limestone was noticed, and 

 its occurrence at this point, with the proper sequence of the 

 Yoredale rocks above (interrupted only by the intrusion of the 

 Basalt), taken together with the previously observed position 

 of the Main Limestone bed, proved conclusively that some- 

 where near the line of the River Tees and also in the Lune 

 Valley, faults must exist which have thrown down (relatively) 

 the strata to the north of the Tees, and also to the south of 

 Harter Fell between Teesdale and Lunedale. 



Collating the various exposures observed along Hudeshope 

 Beck, in Teesdale, and in Lunedale, it becomes strikingly evident 

 that the enormously thick masses of Yoredale limestones seen 



Naturalist, 



