432 ME. S. S. BT/CKMAN ON THE BAJOCTAN [Aug. 1 895, 



nearly in this case may have heen the actual fate of its successor. 

 If the successor have been preserved anywhere, it should be in the 

 Northern Cotteswolds. 1 



The crossed lines in Table VI. show some of the results obtained 

 along another line of country — Kimsbury Castle to Cold Comfort : 

 the most noticeable points being a generally greater thickness of 

 the ' intervening beds ' as a whole, and the preservation of a greater 

 amount of Notgrove Freestone. As this line, before it reaches 

 Birdlip, lies west of the Mount Surat-Leckhampton line, it shows 

 that to the westward the ' intervening beds ' were thicker, and that 

 the Notgrove Freestone had suffered less from denudation towards 

 the west. 



If the whole of the results obtained from this line of country had 

 been given in a diagram to compare with the Mount Surat-Leck- 

 hampton line, it would have been seen that the lines bounding the 

 trough in the latter run very much straighter than those in the 

 former ; in fact, the bend in the latter on the Leckhampton side is 

 only where the direction changes beyond Leckhampton from N.E. 

 to E. But the greater straightness would appear to indicate this 

 — the Mount Surat-Leckhampton line cuts the trough at right 

 angles, while the bending of the boundaries in the Kimsbury-Cold 

 Comfort line shows that this run of the country is at an oblique 

 angle to the trough of erosion. This seems to give a clue to the 

 direction of the trough — namely, that it was at right angles to 

 the line of country plotted by plain lines in Table VI. 



1 In Table VI. I have marked two lines of erosion — an upper and a 

 lower one. The latter corresponds to the 'trough' which has just been 

 treated of, and this ' trough ' seems to be repeated in the Stroud Valley, one 

 of its sides being shown by the rapid rise in the line of beds from Mount 

 Surat to Stroud Hill. But then there is the upper line of erosion from Stroud 

 Hill to Sheepscombe marked by the letters N.E. by N. (with arrow thus, 

 -*»N.E. by N., not those in parentheses), the direction taken. In the direction 

 E.N.E., from Scotesquar to Kimsbury Castle, the upper line of erosion takes 

 a course such as to point to there having been less erosion to the west of the 

 first line ; and with this the greater thickness of Notgrove Freestone at Kims- 

 bury Castle tallies. Then another direction for the upper line of erosion would 

 be S.E. by E. from Kimsbury Castle to Sheepscombe, a dip, according to 

 present data, of about 6 feet in 2^ miles^ (not the line shown in the diagram). 

 Now the two lines of erosion N.E. by N. and E.N.E. do not coincide with the 

 line of erosion shown by the sides of the Birdlip trough ; and it is therefore 

 to be assumed that the Bajocian erosion effected two things : first, it planed 

 the country down to a general level represented in the directions taken by the 

 lines marked N.E. by N. and E.N.E., and roughly by the line drawn across 

 the Birdlip trough, marked ' Upper line of erosion,' which is about the mean 

 of the two lines N.E. by N. and E.N.E., and nearly coincides with the top of 

 the Witchellia-grit on the right hand of the diagram ; secondly, it excavated 

 local ' troughs,' as indicated by the steep line, marked ' Lower line of erosion,' 

 dipping to Birdlip, and also by the line dipping from Stroud Hill to Mount 

 Surat; these two troughs being connected via Miserden, the dip to which, from 

 Sheepscombe, would be about 22 feet in 3^- miles, very similar to the erosion- 

 dip from Leckhampton to Tuffley's. The placing of this matter in a clearer 

 light must be left to another paper, when continuous lines of country can be 

 plotted. Here it will be noticed that the upper line of erosion marked on 

 the diagram does not coincide either with the N.E. by N. or the E.N.E. line, 

 because the continuation of both is a line east. 



