Apparent objections to the Glacial Theory, 293 



rising masses of rock is not of itself sufficient to account for the 

 grooves and striae which are often visible. That such friction, 

 however, is capable of producing some of these phenomena, we have 

 proof in the instance of the " ninety fathom dibe," in the coal-field 

 of Newcastle. This name has been given to it, because the beds 

 are ninety fathoms lower on the northern than they are on the 

 southern side. The fissure has been filled by a body of sand, which 

 is now in the state of sandstone, and is called the dibe, which is 

 sometimes very narrow, but in other places more than twenty yards 

 wide. The walls of the fissure are scored by grooves, such as 

 would have been produced if the broken ends of the rock, had been 

 rubbed along the plane of the fault." — Lyell 1 s Elem. Geol. p. 120. 



Still it may be urged, that such friction could not have acted on 

 horizontal surfaces, nor on external surfaces generally, which exhi- 

 bit no signs of violent fracture; in these cases, another agent is 

 evidently necessary, and if we admit, that at the time when our lands 

 first emerged from the ocean, the strata were in a soft and semi-con- 

 solidated state, we shall perceive that the striae and grooves may 

 have been furrowed upon them by the passage over the surface, of 

 the vast rocky masses which hurled down from the uprising hills, 

 were borne along by the retiring waters, to the lower lands. 



Thus we shall derive assistance from two distinct agents, both of 

 which may have been instrumental, under different circumstances, to 

 the production of the phenomena now attributed to glaciers. 



The partial stratification which some of the supposed moraines 

 exhibit, as in the district where the rivers Esk, Proson, and Carity 

 unite, not only offers difficulties which the glacier theory cannot 

 explain or surmount, but is precisely the very effect to which water 

 alone could give rise. 



" The lower part of the barrier at Glenairn, thirty feet in depth, 

 laid open in the river cliff, consists of unstratified mud full of boul- 

 ders ; and the upper part from fifty to one hundred feet thick, of 

 gravel and sand is inferred by Mr. Lyell from analogy, to be strati- 

 fied. If this barrier be supposed to be a large terminal moraine 

 accumulated by a retreating glacier, Mr. Lyell states, its origin is 

 easy to be understood, and that the water produced by the melting 

 of the ice may have overflowed the mound and furrowed out the 



