354 Sir H. H. Hoiuorth — Geological History of the Baltic. 



evidence of sections. They do not appear to be drawn with due 

 attention to all available facts. They sweep across the deep valleys 

 in the Upper Chalk indicated by the contour-lines at e.g. Burnt 

 House or Standen Copse without any deviation. This could only be 

 truthful in vertical chalk, and there is no ground for supposing that 

 the chalk is vertical in these valleys though inclined in all sections. 

 Even direct evidence from sections is liable to be ignored, as can be 

 readily seen in the case of the great Downend pit. In Fig. 1 there 

 is reproduced the rough outline of the pit. There is a high con- 

 tinuous face along the line a h c, while the line d e marks the 

 strike as mapped for Dr. E.owe. If this strike is correct the highest 

 chalk exposed in this face would be at the point h, and from h to e 

 there would be a repetition of some of the beds exposed from a to h. 

 This is, however, not the case. There is no repetition from h to c, 

 but a gradual passage to higher chalk. The strike must therefore he- 

 at least as nearly E. and W. as the dotted line f g, and such a strike 

 calls for zonal boundaries in this neighbourhood of a trend differing 

 substantially from that given to them in the map and inconsistent 

 with the thinning of the mticronata zone shown. (Incidentally I may 

 say that close to the point b 1 have been able to identify the top bed 

 of the upper band of Offaster pilula in the subzone of abundant 

 Offaster pilula by its usual physical characters and large form of 

 0. pilula. In downward succession from c to a there is first chalk 

 without any marl seams. Below the first marl seam met with there 

 are roughly 32 feet of chalk containing seven marl seams, and then 

 come the two marl seams, 3 feet apart, with a flint line between 

 them, which enclose this top bed.) 



In the face of the foregoing considerations it is hardly possible to 

 accept it as established that the mucronata zone has been entirely 

 denuded away at any point in the Isle of Wight, and much of the 

 alleged variation of that zone in thickness from point to point seems 

 to rest upon a very insecure basis. 



IV. — The Becenx Geological History of the Baltic and Scandi- 

 navia AND ITS IMPOETANCE IN THE PoST-TeRTIAET HiSTOEY OF 



Western Europe. 



.By Sir Henry H. Howoeth, K.C.I.E., F.E.S., F.S.A., F.G.S. 

 Part I. 



SOME years ago I was allowed to publish in the Geological 

 Magazine^ some papers on the recent geological history of the 

 Baltic, in which I tried to bring before English readers the very 

 important discoveries of the Northern geologists as affecting the 

 general geology of the north-west of Europe and to extend their 

 deductions. I was obliged to interrupt them for other work. 

 Perhaps you will allow me to continue them some steps further, as we 

 had reached a stage of some interest. 



The northern portion of the Baltic, generally known as the 

 Bothnian Gulf and comprising an area of over 1,877 square miles, 



^ For previous communications on this subject, see Geol. Mag., Dec. II,. 

 Vol. II, pp. 311, 337 ; Vol. Ill, pp. 1, 550. 



