178 



Tute — Natural Pits near Ripon. 



VI. — On certain Natural Pits in the Neighbourhood of Kipon. 

 By the Rev. J. S. Tute. 



NEAE the city of Eipon, on both sides the river Ure, but more 

 jDarticularly on the eastern side, there are a great number of 

 natural pits, probably fifty or sixty, the origin of which appears 

 to be very obscure. 



They chiefly occur in groups of two, three, or four, in the lowest 

 beds of the New Ked Sandstone, and the overlying drift-gravel ; 

 but there are some also in the Magnesian Limestone. Their general 

 form is crater-like, with a diameter of 40 to 100 feet, the sides 

 having a slope of about 30°. But, in one instance (marked c on 

 the plan), the pit consists of a perpendicular shaft about 30 feet 

 in width and 60 in depth, cut through the New Ked Sandstone. 

 Here the gravel bed is very thin. In another, close to this one, the 

 crater-like hollow terminates in a sandstone shaft, which is nearly 

 filled with water. In a third, a, the sides of the pit, which occurs 

 in the Magnesian Limestone, are perpendicular on one side, but 

 slope gradually down to the bottom on the other. The limestone 

 is thinly-bedded, and in small slabs, dipping evenly to the east, 

 about 5^. 



Plan Exhibiting the Localities of the Principal Pits. 



The crater-like form of these 

 pits is evidently due to the fall- 

 ing in of the sides when a pit 

 has occurred beneath the gravel ; 

 though in what manner the pits 

 themselves have been formed 

 is very difficult to understand. 

 That they are due in some way 

 to the action of water is pro- 

 bable, as they seldom, if ever, 

 occur more than half a mile 

 from the river ; and several of 

 them now contain water. The 

 Magnesian Limestone in the 

 neighbourhood is full of cracks, 

 and swallow-holes, and subter- 

 ranean passages. If any of the 

 overlying rock gave way, this 

 would produce rather irregular 

 subsidences, than such regu- 

 The structure of the New Ked 



N. E. Ry. 



R. Ure 



Sharrow 



RIPON 



N. E. Ry. R. Ure. 

 Scale— \ inch to a miie. 



larly formed pits as these are. 



Sandstone will be understood best from the following copy of a 

 well-sinker's report of a well sunk 28J yards deep, very near to 

 the pit marked d : — 



" After cutting through the soil, which is not very thick, a soft 

 sandy red rock, 10 feet thick, was penetrated, and then a layer of 

 soft marly clay, about 10 inches thick. These clay layers occur 



