538 J. H. Kilroe — Late rite and Bauxite in Germany. 



this, there can he little douht that the clay and contained ore are the 

 result of peculiar weathering in place which the basalt has locally 

 undergone, 



ie) It is a very striking fact that the ores and containing clays, both 

 atMiickaandeastof Garbenteich, have little or no superficial covering. 

 In the latter place I was unable to notice any. To sustain some 

 comparison with the conditions in Antrim I hoped to find the red 

 clay, etc., at rothen Hang passing, in indurated form, under the 

 columnar anamesites of hohen Stein ; but Dr. Schottler assured me 

 that in a well-boring put down 30 or 40 metres at the Abdeckerei des 

 Kreises, near the Lich-Garbenteich road, nothing of the kind was met 

 with. The clay with bauxite on the rothen Hang is therefore 

 absolutely superficial, and the laterites at Miicka, when not so, bear 

 no covering earlier than the Loess. 



(/) The volcanic history of the "Western Yogelsberg commences 

 with tufts in the Giessen Sands, which correspond to those at 

 Miinzenburg, to the south-east, and at Marburg on the north. These 

 follow the Oligocene of Mainz, and are therefore believed to be of 

 Miocene age. The interbedding of tuifs, basalt, and sands ceases at 

 Giessen before the stage of the ' Traps ' is reached, so that the series 

 as a whole is considerably younger than the basalts, etc., of Antrim. 



Moreover, the region, as stated previously, is traversed by post- 

 basalt faults, i.e. later than the third stage of volcanic outpourings ; 

 and it must have undergone considerable denudation since the faulting, 

 to produce the present surface features. Miinzenburg Hill, which is 

 a neck from which lava streamed forth, is now isolated from the group. 

 The pretty feature of Schiifenberg retains only a thin cap of glassy 

 Trap, while it overlooks sedimentary strata which must have been 

 perhaps thickly covered with both Traps and some Lower Basalt. 

 The Frankfurt ^ Section 18, of the geologische Karte by Lepsius 

 (1 : 150,000), shows Pliocene strata in some of the Vogelsberg valleys, 

 e.g. those of Allendorf and Zell and one near Weitershain. It seems 

 quite just, therefore, to infer that the present contours are of Pliocene 

 age, and that the surfaces, in relation to which the ores have been 

 developed, are the result of late Pliocene sculpturing ; and even if we 

 take the palms of the Miinzenburg Sandstone as indicative of a warm 

 climate, we must come much nearer to a Post-Pliocene date and 

 glacial conditions, for the origination of the Vogelsberg laterite and 

 bauxite, than the Miocene or Eocene, with the climatic conditions 

 which then prevailed in our latitude.^ 



Origin of Laterite and Bauxite in the Vogelsberg. 

 It is noteworthy that these substances originate for the most part 

 under tropical conditions.- These conditions are stated as essential by 



' It interests me to find that Miinster questions whether a tropical climate has been 

 a factor in the formation of the Vogelsberg iron-ores and bauxites. Op. cit., p. 257. 



- Whether in Ireland or in Southern France in earlier geological times ; or in 

 India, the Deccan, Malabar, etc., to-day; Georgia, Alabama, Arkansas; Brazil, 

 Surinam ; the ("ongo, East Africa ; the Seychelles, Java, Sumatia, and the 

 Hawaiian Islands — all have their aluminous clays and ores ; and so natural has it 

 become to assume a hot climate that Bauer assumes it (Xeues Jahrbuch, 1898, p. 219), 

 a view mentioned without comment by Doelter (" Petrogenesis," 1906, p. 235). 



