152 W. H. Hudleston — Creechharroiv in Purheck. 



This concludes the description of the Creechbarrow Beds as far as 

 I have been able at present to trace them. If we turn to Fig. 1 

 we perceive that the convenient obscurity afforded by the Blackhills 

 Plantation helps to conceal their possible relation to the Pipeclay 

 series ; all we can say is that, topographically speaking, they occupy 

 the higher ground, and that when we get well below the 300 feet 

 contour the Pipeclay series has possession of the surface. 



LiTHOLOGY AND PALEONTOLOGY. 



The big Flints. — Before entering upon a detailed description of the 

 Creechbarrow Limestone, there are some other matters of interest 

 which may be considered. The first of these refers to the very large 

 flints which have contributed in no small degree to the maintenance 

 of the fabric of Creechbarrow, and which are such an exceptional 

 feature in the Bagshot beds of this immediate district : their strati- 

 graphical relations may be gathered from the preceding pages. As 



Fig. 2. — One of the mauganese nodules from the eastern spur of Creechbarrow. 

 Eeduced f (from a photograph). 



regards the general character and appearance of these flints, they are 

 for the most part of a dirty cream-colour ; they are also much 

 degelatinized, and in some cases the exterior is simply a mass 

 of granular silica, very meagre to the touch. They are also 

 extremely brittle when first dug out, though it is probable that 

 exposure to the atmosphere toughens them after a while. In 

 consequence of this brittleness the available fragments do not much 

 exceed 28 lb. in weight, so far as I have seen them, though it may 

 well be that heavier flints than these occur. These flints have split 

 in the bed itself. The surface of those flints which are not much 

 broken has been subject to very little modification from abrasion. 

 Associated with the big flints are flint pebbles and other stones 

 of moderate size, also quartzose grit. 



The peculiar fawn colour of these siliceous masses will help 

 to distinguish them from ordinary plateau-gravel or valley-gravel 



