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XXIX. On the Geology of Hawe*. i??/ John Phillips, ^i-g-. 



F.G.S. S)X. Sfc. 

 'T'HE general accordance in the nature and order of suc- 

 -*- cession of the strata of the opposite coasts of England 

 and France, has been demonstrated by several eminent geo- 

 logists. Dr. Fitton has shown that the " denudation" of Sus- 

 sex is continued across the Channel into the Boulonnais; and 

 Mr. DelaBeche has traced the oolitic system of the South 

 of England into the interior of Normandy. The object of the 

 present communication is to make known the appearances ob- 

 servable at a remarkable point of the French coast near Havre, 

 where the chalk and the beds beneath it are exhibited in a 

 very instructive section ; and to compare the order of stratifi- 

 cation which there prevails, with the analogous series of En- 

 glish rocks. 



The complete series of the formations beneath the chalk 

 has been only lately ascertained, and they can be seen together 

 in very few situations. In consequence of unconformity of 

 stratification, the chalk and green-sand are found to rest, in 

 different situations, on very different members of the inferior 

 formations. One remarkable example of this kind on the South 

 coast is explained by Mr. De la Beche, and another is repre- 

 sented in one of the sections which accompany my " Illus- 

 trations of the Geology of Yorkshire." 



But besides the discordance introduced by this want of con- 

 formity in their planes and areas of deposition, considerable 

 deviations happen in the nature and thickness of the strata be- 

 neath the chalk. The total disappearance of the green-sand 

 from the escarpments of the wolds of Lincolnshire and York- 

 shire is probably not due to an unconformity between it and 

 the chalk, but to a real deficiency of the deposit. 



To illustrate so variable a series of strata, it is desirable to 

 bring together sections taken in distant places, and to confirm 

 the order of succession by a careful comparison of the organic 

 remains. 



The chalk in the neighbourhood of Havre is the lowest part 

 of that thick stratum, and is remarkably stored with large bhick 

 nodular flints, arranged in parallel rows, at unequal distances, 

 in some parts closely crowded, while above and below they 

 are scattered far asunder. 



Organic remains do not appear to be plentiful. In pro- 

 ceeding from Havre along the shore towards the N.W., we 

 observe the strata beneath the chalk. At a small village about 



• l^cad l)cforc the Yorksliirc Philosophical Society, December 2, 1829; 

 and ('oiinniinicatcd hy tliu Aulhur. 



'2 C 2 a mile 



