Mr. Hutton on the Stratiform Basalt. 



209 



got over, and the stratum of Basalt on the north-east side will be the 

 Whin Sill, itself broken by the subsequent action of the Trap Dyke. 

 An analogous case to this is exhibited at Burtree Ford, in Weardale, 

 where the broken edges of the Whin Sill may be seen associated with 

 several other beds of the formation dipping in opposite directions from 

 a great central mass of Whin which is evidently a Dyke, and which 

 may be traced cutting the strata on either side of the burn.* 



No 12. — Sketch of the appearance of the Strata at BURTREE FORD, in Killhope Burn. 



* Since this paper was read to the Society, I have examined Lunedale, and particularly 

 the district round Saddle Bow. It is difficult to ascertain exactly the nature and position 

 of the rocks of which this curious hill is composed from the thick covering of vegetation, 

 but they appear to be as below. 



Section of the HILL of SADDLE BOW, in Lunedale. 



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* \ 







\ 





If I am correct, it will follow that the Basalt in this hill has not been the cause of the con- 

 fusion by being protruded after the consolidation of the strata, as might be inferred from 

 Professor Sedgwick's remarks and Section above referred to, but that the two beds are por- 

 tions of Basaltic strata, with intervening members of the Mountain Limestone series, either 

 slipped down from the hill above, or broken and tilted as represented. The whole of the lower 



