J. B. Kilroe — Laterite and Bauxite in Germany. 535^ 



which a sufficiently comprehensive view of the origin of those 

 substances may ultimately stand. On this account my visit to the 

 region was approved by the Department of Agriculture in Ireland, 

 in connection with the work now in progress on the iron- ore and 

 bauxites of co. Antrim. In my traverses I enjoyed the very agreeable 

 companionship of Dr. Schottler, of the Grossherzoglich Hessischen 

 Geologischen Landestaldt, and the advantage of his guidance. His 

 elaborate description of the basalts in the vicinity of Giessen^ has 

 since been issued, and is referred to in this paper. The admirable 

 and exhaustive accounts of the bauxite by Professor Adolf Liebrich,'* 

 and of the iron-ore by H. Miinster,^ are also appealed to frequently. 

 Among other important papers consulted regarding the chemical 

 processes involved may be mentioned those of M. H. Coquand,* 

 Professor G. A. Cole, F.G.S., M.E.I.A.,* Max Bauer,« Sir T. H. 

 HoUand, A.R.C.S., F.R.S.,^ H. Warth, D.Sc^ & F.J. Warth, B.Sc.,« 

 Malcolm Maclaren, B.Sc, F.G.S.,» H. Brantwood Muff, B.A.,>« and 

 the summaries by F. "Wigglesworth Clarke " and Dr. C. Doelter.^^ 



The principal points which came under my observation may be 

 briefly summarized as follows : — 



{a) In the Vogelsberg the ores do not lie in a common zone, or 

 in a zone or zones geologically distinct, and are not associated with 

 lignite. 



(J) Laterite with iron-ore is developed in irregular tracts on. each 

 side of a post-basalt dislocation. 



(c) The best iron-ore (limonite and non-pisolitic earthy ore) has 

 accumulated below a thick more or less ferruginous layer of completely 

 weathered basalt, clay with pseudo-stratified arrangement. 



{d) This ore is formed chiefly, if not wholly, fi'om lavas of the 

 lowest stage, while the bauxite is chiefly derived from those of the 

 succeeding stage. 



((?) The ore-bearing clays carry only a thin covering, if any, of 

 Post-Pliocene date, and are of superficial origin. 



(/) The date of their origin, therefore, probably late Pliocene. 



Taking these points seriatim we find — 



1 Abhandlung der Grossherz. Hessisch. Geol. Landes. zu Darmstadt, Band iv, 

 Heft iii, "Wm. Schottler. 



2 28th Bericht der Oberhessischen Gesell. fiir Natur- vind Heilkunde. 



3 "Die Brauneisenerzlagerstatten des Seen- und Ohmtals am Nordrand des 

 Vogelsgebirges " : Zeitsch. fiir Prak. Geol., 1905, p. 242. 



* " Sur les Bauxites de la Chaine des Alp.": Bull. See. Geol. de France, 

 tome xxviii (1871), p. HI. 



6 "The Rhyolites of the County of Antrim": Sci. Trans. Roy. Dub. See, 

 1896, ser. ii, vol. vi. 



« " Beitrage zur Geologic der Seyschellen " : Neues Jahr. fiir Min. Geol. und 

 Palaeontologie, 1898, p. 163. 



■> " On the Constitution of Laterite" : Geol. Mag., 1903, Vol. X, p. 59. 



8 " The Composition of Indian Laterite " : Geol. Mag., 1903, p. 154. 



? " On the Origin of certain Laterites " : Geol. Mag., 1906, Dec. V, Vol, III, 

 p. 536. 



1° " East Africa Protectorate." 



11 " Data of Geochemistry" : Bulletin No. 330, U.S. Geol. Survey, 1908. 



12 "Petroarenesis '' 1906. 



