XXX
workable beds of coal, which are referred by German geologists to the Wealden. These beds have been very fully described, and their numerous points of resemblance to the English Wealden shown, by many German geologists, especially by Koch, Dunker, and Von Meyer*, and more recently by Credner†. In Brunswick this formation does not occur ; and the presence there of Lower Neocomian beds is therefore a very significant fact.
With regard to the stratigraphical relations of the Neocomian beds in North Germany it is not easy to arrive at any very definite conclusion, the country not having been mapped in sufficient detail. The manner, however, in which the Cretaceous beds are found overlapping and resting on different members of the Neocomian appears to indicate the existence, as in England, of an unconformity between these two series. Similarly the Hilsconglomerat (Lower Neocomian) of Brunswick appears to lie indifferently on any of the older rocks, and is therefore probably unconformable to the Jurassic series.
VI. Conclusion.
We have thus seen that the Neocomian beds of Yorkshire and Lincolnshire are the most westerly development of a great mass of strata, of the same age, stretching over a wide area in Northern Europe. It is true that the beds of this age are neither so well exposed nor do they attain so great a thickness as in the south of Europe ; but they nevertheless present us with a remarkably similar succession of faunas. At the eastern and western extremities of the area, in Brunswick and in Yorkshire respectively, the marine series is complete, and we have the three divisions of the Neocomian formation all developed ; but in the intermediate districts of Westphalia, Hanover, and the Hartz, the marine beds represent only the Upper and Middle Neocomian, and these rest upon the freshwater strata of the North-German Wealden.
The section at Speeton Cliff derives additional interest from the fact that it is by far the most complete exposure of the Neocomian beds over the whole of the great North-European area. The sections elsewhere are more or less isolated and fragmentary ; but at Speeton we find the key by means of which they may be identified and correlated.
We have seen that, over the North-European area, a remarkable uniformity of character is maintained among the Neocomian strata (and the same is, to a certain extent, true also of the Cretaceous and Jurassic), indicating that this district forms a natural province, not improbably representing an ancient sea-basin. The ridge of Palaeozoic land traced by Mr. Godwin-Austen in his celebrated memoir " On the Possible Extension of the Coal-Measures beneath the South-Eastern part of England "‡ may not improbably have formed
- " Monographic der Norddeutschen Wealdenbildung," &c. (1846), Palseon-
tographica, &c.
t Ueber die G-liederung der oberen Juraformation und der Wealden-Bildung im nordwestlichen Deutschland (Prague, 1863).
| Quart, Journ. Geol. Soc.vol. lii. 1856, p. 38. See also Mr. S. V. Wood, jun.,
