TRANSLATIONS ANi) NOTICES 



OP 



GEOLOGICAL MEMOIRS. 



On the BiscovEKY in Hautaut, helow tlie Saistds referred hy Dtjmont 

 to the Than^et Sands, of a coakse Limestone with a Tertiary 

 Eatjna. By MM. F.-L. Cornet and A. Briart. 



[Note sur la decouverte dans le Hainaut, en dessous des sables rapportes par 

 Dumont au Systeme Landenien, d'un calcaire grossier avec faune tertiaire ; par 

 MM. F.-L. Cornet et A. Briart. Bidletin de lAcademie royale de Belgique, 

 2me s6rie, tome xx. no. 11]. 



At Tournay, Angres, and other localities in the southern part of 

 Hainaut, the Thanet Sands (Landenien inferieur of M. Dumont) are 

 seen overlying the Secondary formations, having at their base a giau- 

 conitic bed. which contains numerous badly preserved fossils. Among 

 these, however, there occurs abundantly an easily recognizable shell, 

 the Pholadomya Koninckii of M. Nyst. MM. d'Archiac, Dumont, and 

 Hebert considered this bed to be the lowest of the Tertiary strata of 

 Belgium, and the equivalent of the " Glauconie inferieure" which 

 forms the base of the Tertiary formation of the Paris basin. 



The object of the authors is to refute these opinions by proving 

 that there exists in Hainault, at a lower level than the glauconitic 

 beds of Tournay, &c., a fossiliferous bed, of which the described 

 species belong to a Tertiary stage of the Paris basin, superior to the 

 *' Glauconie inferieure" of M. d'Archiac. 



At Limbourg, in the environs of Heers, M. Dumont discovered 

 some marly and glauconitic beds lying below his '^ Landenien infe- 

 rieur;" to these he assigned the name "Heersien," and classed 

 them with the Cretaceous formation of Belgium. M. Hebert, how- 

 ever, from palseontological and stratigraphical evidence, considered 

 them to be Tertiary, and Sir C. Lyell suggested the creation of anew 

 system, in which should be included the pisolitic limestone of France, 

 and the stages " Heersien" and " Landenien inferieur" of Belgium. 



From this and other discoveries, the existence in Hainault of these 

 intermediate beds had long been suspected. At the beginning of this 

 year, M. Goffint sank a well on the confines of the town of Mens, 

 near the Obourg station, to the depth of 68 feet, when water was 

 reached. It presented the following section, in descending order : — 



1. Grey sand, containing fragments of flint. 3 feet 6 inches to 4 feet. 



2. An irregular bed composed of fragments of flint and phthanite. 4 inches 

 to 8 inches. 



3. Yellow ferruginous sand, containing grains of glauconite. 8 inches to 

 12 inches. 



4. Fragments of flint and of coaly phthanite. 4 inches to 6 inches. 



5. Very glauconitic sand, very green, and a little argillaceous in the lower 

 part, but colo\ired and soft in the upper part ; it contains fragments of phthanite. 

 15 feet 3 inches. 



6. Very ferruginous red sand, containing limonite and numerous masses of a 

 VOL. XXII. PART II. D 



