138 DESCRIPTION OF THE STRATA. 



While the compact schistus generally presents a perpendicular 

 face, like a vast wall, verj^ frequently smooth and even, the whole 

 of the aluminous beds, where they front the sea, form steep clifl's, 

 sometimes perpendicular, and sometimes overhanging. Hence, as 

 the higher parts of the rock have such a tendency to split, the exa- 

 mination of the beds beneath is attended with danger, especially after 

 frosts, or heavy rains. Fatal accidents have in many instances occur- 

 red, by the falling of portions of the rock on persons below. The 

 most singular accident of this kind ever known, happened about 13 

 years ago, on the shore between Staiths and Boulby. While two 

 young girls, sisters, of the name Grundy, belonging to Staiths, were 

 sitting together on the scar, or rocky pavement of the shore, a splinter 

 which fell from the higher part of the cliff, and by hitting some pro- 

 jecting ledge of the rock acquired a rotatory motion, struck one of 

 the girls on the hinder part of the neck, and in a moment severed her 

 head from her body. The head was thrown forward, and rolled 

 along the scar to the distance of several yards. 



The thickness of the hard and compact schistus may be stated 

 at 30 feet. This statement, however, is simply intended to give a 

 general notion of its relative magnitude. Its actual dimensions can- 

 not be given with much precision ; there being no distinct line of 

 separation, between this part of the rock and that which precedes it. 



There is, however, a well defined parting, between the compact 

 shale and the next member of the aluminous strata (marked m), which 



consists of IRONSTONE, IN BEDS, OR ROWS OF NODULES, INTERSTRATI- 

 FIED WITH SHALE. 



The ironstone beds or seams of this portion of the strata bear a 

 strong resemblance to those of Gristhorpe, Cayton, and Burniston ; 

 consisting, partly of solid seams, most of which are from 5 or 6 

 inches to 8 or 9 in thickness ; partly of rows of nodules, having their 

 interstices filled up with coarse shale. These seams abound with 



