14^ COAL UNDER SOUTH-EASTERN ENGLAND. 



of Colchester would be a good place, as in that district the top of the Chalk is 

 within a few feet of the surface, and it is also obviously better to begin near the 

 place at which Lower Carboniferous rocks are known to exist than where beds of 

 some other series are more likely to occur, as in Western Essex. An additional 

 presumption in favour of this spot seems to me to be furnished by its position 

 with reference to the area within which structural damage was done by the Essex 

 earthquake of April, 1884. If a straight line be drawn, having a north-west and 

 south-east direction, parallel with the general course of the Colne between 

 Colchester and the sea, and about two miles east of the river, this line gives us 

 the eastern limit of damage. The western limit might be similarly shown by 

 a line parallel with the first and connecting Coggeshall with Tillingham, south of 

 the Blackwater, the northern boundary being another line between Coggeshall 

 and Colchester. Of course there are a few outlying places at which some damage 

 was done, but at least nineteen-twentieths of it took place within the area 

 described, as may be seen on the map given by Professor Meldola and Mr. White 

 in their report on this earthquake.^ Now it seems to me that the most probable 

 explanation of the restriction of the damage to so compact and limited a district is 

 to suppose that the ancient subterranean ridge or plateau is unusually near the 

 surface there, while it speedily becomes deeper towards the north-west of Colchester. 

 And as we may expect Coal Measures, not on the ancient ridge, but here and 

 there on its more northerly flank, it seems best to begin operations a little north- 

 east of the area of earthquake-damage. 



P.S, — The result of the Culford boring (learned since the above Report was 

 sent in) does not seem to me to make any modification in what I have written 

 desirable. 



IL— REPORT BY W. WHITAKER, B.A., E.R.S., F.G.S., 

 ASSOC. INST. C.E. {^Hon. Mem. Essex Field Club). 



The question of the probability of an uprise of Older Rocks underground in 

 the South-East of England was first started, as a matter of reasoning, a good 

 many years ago. The effect of such an underground uprise would be to interrupt 

 the continuity of many of the beds below the Chalk, by bringing much older 

 formations nearer to the surface than they would be if the Upper Cretaceous 

 beds were duly underlain by Lower Cretaceous, Jurassic, etc., as at the outcrops 

 on the north, west, and south. 



The line of reasoning was as follows : It was suggested that the uprise seen 

 in parts of South Wales and in the Bristol district, with a general direction more 

 or less west and east, was likely to be connected underground with the other like 

 uprise through Northern France and the neighbouring part of Belgium, although 

 that connection was hidden at the surface by a covering of Tertiary, Cretaceous, 

 etc., rocks. As a consequence of this hidden uprise the continuity of the Jurassic 

 and Triassic rocks underground would be imperfect, so that in many places the 

 Cretaceous beds would be found to rest directly on much older rocks, whilst in 

 other places these two might be separated by no very great thickness of Jurassic 

 rocks. 



It was argued, too, that amongst the older rocks thus brought nearer to the 

 surface Coal Measures were likely to occur, probabl}'' in a set of separate masses, 

 as in South Wales and round Bristol. 



3 " Report on the East Anglian Earthquake of April 22nd, 1884." ( " Essex Field Club 

 Special Memoirs," vol. i.) London : Macniillan & Co., and Essex Field Club, Buckhurst 

 Hill. 



