98 Dr. G. Forchammer's Geological Observations 



The author then presents us with some reasons for sup- 

 posing that this equivalent of the calcairc grassier has taken 

 some of the characters of the plastic clay, and proceeds ; 



" That the calcairc grassier has here partly preserved the 

 character of plastic clay is proved by the Cyprincc, which are 

 common, and which are found in the latter in the Isle of 

 Wight ; the Astartc, a characteristic fossil at Antwerp, is fre- 

 quently found in clays, referred for the most part to the plastic 

 clay. Many of the shells of the calcairc grassier of Antwerp 

 belong equally to the plastic clay, or x'ather to the point of 

 contact or mixture of tlie two formations. 



" Beds, therefore, exist in Belgium analogous to the lower 

 part of the first marine formation {calcairc g7-ossier) of the 

 Paris basin, and these beds are in general characterized by 

 the presence of silicate of iron, by sharks' teeth, Nummulites, 

 many species of Astnrte, Pectina, Cyprince, Pectunculi, &c." 



The author then describes the upper sands 'without shells, 

 which he refers to diluvium, and notices the finding of ele- 

 phants' bones in it at Antwerp, Vilvorde, &c. ; and after men- 

 tioning the alluvial deposits, he adds: 



" A tertiarj' basin exists in Belgium, bounded by chalk hills, 

 which, quitting the coast of France, form a zone, asM. Prevost 

 has noticed, that passes near Mons, Liege, Maestricht, &c. 

 This basin appears to resemble that of the E. of England *, 

 and probably contains many beds equivalent to those of the 

 environs of Paris. At Antwerp we have examined beds which 

 appear referable to the plastic clay, the lower part of the 

 calcaire grassier, diluvium, and alluvium." 



4. Geological Observations on Sieland and the Neighbma-ing 

 Islands [Denmark); by Dr. G. Forchammerf. 



Two cretaceous formations are observable in these islands : 

 one the same with the chalk of England and France ; the other 

 apparently analogous to the plastic clay or ccdcaire grassier. 

 The limestone of Saltholm and Limhamn, which resembles 

 chalk in its mineral structure, has a N.N.W. or S.S.W. di- 

 rection, in which the following beds agree. The fragments of 

 limestone found round Fursoen, and which abound in the 



* The term badn is objectionable either as applied to the superior or 

 tertiary deposits of the East of England or Belgium, as both only form 

 the western continuation of the great mass of tertiary rocks which traverses 

 the centre of Europe, and bend down towards the Black Sea. — Trans. 



\ From a notice in Baron de Ferussac's Bulletin des Sciences for March 

 1826, of the author's remarks in Oersted, Oversigt over dct K. Danske 

 Videnskab. selsk. Forhandl., 1825; and shows the character under which 

 the chalk, plastic clay, and calcairc grassier exist in Denmark. — Trans. 



con- 



