184?6.] PIlESTWlCfl AND.MOURIS ON^ THE WEALDEN STRATA. 403 



As the railway traverses these Wealdeii strata for a distance of 

 four miles at right angles to their strike, and as the dip of the beds 

 both at Tunbridge and Tunbridge Wells is a few degrees northward, 

 it might lead to an inference of a considerable vertical development 

 between these two points; but this however does not appear to be 

 the case. 



The first portion of our section at Tunbridge shows probably the 

 lower part of the Wealden clay with the upper beds of the Hastings 

 sands rising from below them, the line of separation, if such it may 

 be termed, being well-defined both by change of condition and slight 

 irregularity of connecting surfaces. (See point a in the Quarry Hill 

 section, fig. 1.) The clays and shales which again appear at the 

 end of this cutting beyond the fault, we consider to be a repetition 

 of the strata B. From the dip of these clays there can be little 

 doubt that the sand-rock at the forty-two-and-a-half mile-post un- 

 derlies them ; and it is probably a continuation of this bed which 

 reappears in the next section (D), having however a reversed dip to 

 the south. 



The position of the dark clays in the Southboro' Hill section is 

 apparently obscure ; at first sight, from their dip and position, they 

 appear to be a prolongation of the cypriferous shales at the hill north 

 of the Powder Mills* ; but as they differ from them in their non-fossi- 

 liferous character, and as they evidently underlie the whole mass of 

 the sandstone forming the high ridge from Southboro' Hill to Tun- 

 bridge Wells, where we see them again cropping out from below the 

 sandstone at the south end of the tunnel (see section, Tunbridge 

 Wells), we are rather inclined to consider them as lower in the 

 series, their present continuous level with the clays (B) of the pre- 

 ceding section (north of Powder Mills) being due to the disturbances 

 hereafter alluded to ; for if they represented a prolongation of those 

 clays, the sandstones of Southboro' Hill and Tunbridge Wells would 

 (the strata at Quarry Hill and at the hill north of the Powder Mills 

 being equivalents) be more recent than those of the Quarry Hill 

 section, which have been shown to underlie the cypriferous clays, 

 and consequently would have to be regarded as subordinate mem- 

 bers of the mass of the Weald clay between Tunbridge and the 

 greensand escarpment, — a district, the physical features of which 

 seem to preclude the possibility of the recurrence of any such im- 

 portant sandstone strata. 



As therefore the shales (E)are not higher in the series than those 

 (B) at Quarry Hill, and further, as they do not appear to bo syn- 

 chronous with them, we must assign to them a lower position, in 

 which case the sandstones at the section east end of Soiitiiboro' 

 Hill and at the north entrance of the Tunbridge Wells tunnel might 

 be the lower part of those (D) at the Quarry Hill section, and con- 



* There is however no reason \vl\y tlie shales at the first-named cutting niifilit 

 not 1)C an upper and non-fossilifcrous hiyer of the shaU's at the last rutting, hut 

 in this case we ought to find the ey]n-ifenius strata eropjjing out tt) the south of 

 'fuiihiidge \V<!Us. To this we cannot speak fioni personal ohscrvation, and we 

 an; not aware that such a fact has hcen noticed. 



