ON A RECENT SUBSIDENCE AT MUCKING, ESSEX. 



2 43 



These depressions were in a line from 400 to 800 yards westward 

 ■of the recent subsidence, and their similarity in shape and 

 breadth, though their sides were sloped, certainly makes this 

 view highly probable. The only other explanation of their 

 existence would be to consider them as simply disused gravel- 

 pits. But their uniformity of shape, and distribution along a 

 line across a single field, makes any supposition of this kind 

 improbable in the extreme. For there is plenty of surface gravel 

 in the fields around all the depressions mentioned, and many 



/ 2- 



10 



20 Feel 



Section No. 1 — Mucking Subsidence (190b). No. 2— Blackheath Subsidences 

 {April, 1878, and November, 1880). Both the latter were practically identical 



in size and shape. 



gravel pits in all directions. There is no gravel at the surface of 

 the recent subsidence, simply because it is at the head of a slight 

 valley ranging southward from the plateau of old Thames gravel 

 in which these (in all probability) older subsidences occurred. 

 About a week later, wishing to examine the country west of 

 these depressions, I noticed a shallower hollow of similar shape, 

 on the southern side of the footpath leading to Orsett, in the 

 field north-west of the Cock Inn, 



It seems necessary at this point to introduce a brief account' 

 of the geological structure of this district, by which I mean that 



