i\6 Rev, W, t), Coni/heare on a Geological Map of [Sept. 



formations are wanting (an instance of want of conformity in 

 their direction), and the chalk, with a few beds of green sand, 

 there called Turtia, rest horizontally on the truncated edges of 

 the coal formation, which extends thence along the banks of 

 the Meuse to Liege and Aix : the coal is here even worked 

 beneath the chalk. North of Valenciennes, the edge of the 

 chalk appears to trend to the east, but it is generally overlaid 

 by the sandy superstrata through the Netherlands ; it may, 

 liowever, be seen on the south of Maestricht, and at Henri 

 Chapelle near Aix.* 



(D.) Germany, 



As in the Netherlands we have traced the chalk skirting the 

 north border of the coal fields which repose against the transi- 

 tion chains, so we find on crossing the Rhine the lower beds of 

 the chalk formation (craie chloritee verdatre) similarly placed in 

 the prolongation of these lines in Westphaha, i. e. to the north 

 of the coal fields of the Rahn extending from Unna by Soist to 

 Geseke and Lichtenau. Thence, after an interruption caused by 

 the alluvia of the Lippe, it reappears near Domhagen and Pader- 

 bom, and forms at the foot of the muschelkalk a series of little 

 escarpments, which extend by Schlangen, &c. beyond Hilter, in 

 Osnaburg.t 



To the north of the secondary hills of Westphalia, the whole 

 district is well known to present the appearance of an uniform 

 and vast sandy heath, covered with a deep accumulation of dilu- 

 vial gravel, in the midst of which occur enormous rounded 

 blocks of granite, for which a source cannot be found nearer 

 than the opposite shores of the Baltic — thus exhibiting one of 

 the most striking problems submitted tp the investigation of 

 geology. The great mass of this gravel, however, consists of 

 chalk Hints, well marked, and bearing traces of all the character- 

 istic fossils : at least nine-tenths of the whole consist of these ; 

 a sign that the parent formation can be at no great distance. 

 In such a tract, a rock in situ is like an oasis in the desert ; at 

 Luneberg, however, the fortifications are partly constructed on 

 a rock of gypsum, and about a quarter of a mile hence, on the 

 left of the road to Hamburg, the writer of this article was grati- 

 fied by detecting a chalk-pit which had escaped the attention of 

 former observers : it contains the usual alternation of flints, and 

 affords good specimens of the inoceramus, echinites, and most 

 of the characteristic fossils. 



Dr. Boue also notices a similar patch of chalk at Mount 



• There are other chalky districts in the south-west of France connected with the 

 basin of the Garonne, but these being apparently unconnected with the great chalky 

 area, occupying the interior of the principal European basin, will be mentioned in the 

 close oi this article. 



-f- I copy tliese localities from an excellent article of Boue*s on tlie Geology of Ger* 

 many, which appeared in the Journal de Physique for May, 1822. I have to regret 

 that 1 was not earlier aware of the existence of this article. 



