262 Davies — Phospkatic Deposits in Nassau. 



IV. — On tue Deposits of Phosphate of Lime recently dis- 

 covered IN Nassau, North Germany. 



By D. C. Davies, Oswestry. 



THE little duchy of Nassau, so recently annexed to the kingdom 

 of Prussia, has long been famous for its mineral wealth. It 

 yields yearly about 350,000 tons of iron ore, principally Hematite, 

 and about half that quantity of Manganese. Of its natural mineral 

 water from Seltzers it exports above a million bottles annually. In 

 its north-western corner are the Brown-Coal deposits of the Wester- 

 wald ; and to these sources of wealth must now be added more 

 valuable and extensive deposits of phosphate of lime, which, though 

 not long since discovered, have already attracted the attention of the 

 leading agricultural chemists of this country. This discovery has 

 its scientific attractions, as well as its commercial advantages ; and, 

 as I have lately had an opportunity of examining these deposits in 

 detail, it may be of interest to the reader, if I record a few par- 

 ticulars concerning them. 



The principal phosphoritic deposits of Nassau occupy an irregular 

 area, bounded on the north-east by the town of Weilburg, on the 

 north-west by the Westerwald, on the east by the Taunus Moun- 

 tains, and on the south by the town of Dietz. South of this point, 

 as well as north-east of Weilburg, there are traces of the occurrence 

 of the deposit ; but, from the nature of the underlying rock, they 

 will, I think, be found limited in their extent. Inside the eastern 

 and southern boundaries of this district flows the river Lahn, which 

 is made use of at various points along its course for the purpose of 

 washing the Phosphorite from its surrounding clay, as well as for the 

 carriage of the washed material to the junction of this river with 

 the Rhine at Oberlahnstein. The basement rock of this district is 

 porphyry, varying in colour from dark to light gray and green ; the 

 green is thickly studded with cavities, containing calcareous matter, 

 which, after long exposure to the atmosphere, decomposes and dis- 

 appears. Upon this rock, in its many varieties, rests a succession of 

 slaty and shaly beds (schiverstein) which are greatly contorted and 

 twisted ; these again are overlaid by a great thickness of dark red 

 sandstone beds, which, in places, contain deposits of Hematite. 

 Over a large portion of the district these rocks are capped uncon- 

 formably by a thick deposit of massive limestone (Dolomite), which 

 ranges in colour from bluish gray to pink and bluish white. It is 

 resting upon this limestone that the Phosphatic deposit is found ; 

 the whole series being crowned with a covering of brown clay (Tohn) 

 which sometimes assumes a shaly appearance, and which also, in its 

 upper portion, occasionally contains numerous fragments of the 

 adjacent rocks. 



These rocks have, by German geologists, been referred to the 

 Devonian Group, an opinion which is strengthened by the similarity 

 of the contour of the land to that of Devonshire. Some have 

 even ventured to assign to each rock its exact place in the Devonian 

 series ; but the difficulty of co-ordinating these rocks with those of 



