370 REPORT OF NATIONAL MUSEUM, 1899. 



the Rhone at Bellegarde, Seyssel, and Grenoble. As in England, the 

 phosphatic nodules of the northern area, such as are of commercial 

 importance, occur in both the Upper and Lower Greensands. They 

 resemble in a general way the English phosphates, but are described 

 as soft and porous and easily disintegrating when exposed to the air. 

 Those of the Upper Greensand average some 55 per cent of phosphate 

 of lime. 



More recently deposits have been described by M. J. Gosselet, 1 near 

 Fresnoy-le-Grand, in the north of France. The phosphatic material 

 occurs in a zone of gray chalk some 6 feet in thickness (1 to 2 meters), 

 and is in the form of concretionary nodules forming a sort of con- 

 glomerate in the lower part of the bed. A portion of the chalk is 

 also phosphatic. Phosphatic material (of the type of phosphorites) is 

 found in fissures and pockets in the upper portion of limestones of 

 Middle Jurassic (Oxfordian) age, in the departments of Tarn-et- 

 Garonne, Aveyron, and Zoti, France. 



The deposits are of two kinds. The first occurring in irregular 

 cavities or pockets never over a few yards long, and the second in the 

 form of elongated leads with the sides nearly vertical. These are 

 generally shallow, and thin out very rapidly at a short distance below 

 the surface. 



The nodules or concretions are of a white or gray color, waxy luster, 

 and opal-like appearance, and occur in the form of tubercular or kidney 

 shaped masses embedded in ferruginous clay in the clefts of the lime- 

 stone, or in geodic, fibrous, and radiating forms. 



The material of this region is known commercially as Bordeaux 

 phosphate, being shipped mainly from Bordeaux. They average from 

 70 to 75 per cent phosphate of lime, the impurities being mainly iron 

 oxides and siliceous matter. 



Gautier 2 describes deposits of phosphates estimated to the amount 

 of 120,000 to 300,000 tons on the floors of the Grotte de Minerve, near 

 the village of Minerve on the northeast flank of the Pyrenees, in Aude, 

 France. The cave proper is in nummulitic limestone of Eocene age, 

 the floors being formed by Devonian rocks. The filling material con- 

 sists of cave earth and bone breccia below which are the aggregates of 

 concretionary phosphorites and other phosphatic compounds of lime 

 and alumina, the more interesting being Brushite^ a hydrous tribasic 

 calcium phosphate hitherto known only as a secondary incrustation on 

 guano from the West India islands, and Minervite, a new species hav- 

 ing the formula A1 2 O 3 . P 2 O 5 , 7H a O, a hydrous aluminum phosphate, 

 existing in the form of a white plastic clay-like mass filling a vein 

 from a few inches to 2 or more feet in thickness. 



Germany. According to Da vies, the principal phosphate regions of 



1 Annales de la Societe Geologique du Nord., XXI, 1893, p. 149. 



2 Annals des Mines, V, 1894, p. 5. 



