WORGRET HILL AND WAREHAM WATER SUPPLY. l6l 



A very interesting and instructive section of these beds was 

 disclosed in January, 1905, during the excavation for the 

 reservoir on the summit of Worgret Hill. The excavation was 

 more or less a true square, and I selected the eastern side as a 

 type of the whole (see Fig. 3, based on a photograph taken by 

 Mr. Churchill). The face of gravel here is remarkably vertical, 

 and the gravel holds together so well as to cause surprise to 

 some of the workmen. The peculiar interest of the section at 

 the reservoir arises from the discharged colour noticeable in the 

 upper part of the Plateau-gravel owing to the action of peaty 

 acids having dissolved out or reduced the colouring matter, 

 chiefly iron and manganese oxides. This no doubt may be seen 

 to a certain extent in most gravel pits ; but here a further feature 

 has been produced, viz., the irregular piping of the yellow 

 unreduced gravels by percolation from above. The details of 

 the case are explained in the legend attached to Fig. 3. There 

 is a quarry at the extreme eastern end of Worgret Hill where the 

 same peculiarity is noticeable. As this represents the end of the 

 spread of Plateau-gravel, it may be that lack of lateral support 

 has produced the tendency to piping. 



Particulars of the Bagshot Beds. 



The Higher Sand-series (A).' The general character of these 

 beds on the surface is that of the ordinary pale yellow Bagshot 

 Sands of the district. The water-logged sands at the base 

 (A. d of the column) described as fine in the section, are 

 certainly coarse, where they are seen to come out on the dip 

 slope, and contain much water (the top water). 



The Higher Clay -series (^B). Some of the features of this 

 group have already been described under the " history of 

 operations." The fruits and plant remains are approximately 

 on the same horizon as those from Norden and Bournemouth. 



The Second Sand-series (C). The most interesting bed in 

 this series is the one indicated in the table as C. b which contains 

 such a large quantity of water. This is composed of angular 



