A. Vaughan Jennings — Geology of Bad Nauheim. 353 



In the quarries south of Bad Nauheim or round the village of 

 Ockstadt there is a series of sands, sandstones, pebble-beds, and 

 loosely cemented conglomerates, which are horizontally stratified 

 and evidently of far later date than the rocks of the hill. They are, 

 in fact, Tertiary beds representing the infilling of a great lake which 

 once occupied the whole of the western district. 



If one crosses the broad zone of fertile fields covei-ing these later 

 strata, the hill at Friedberg shows another abrupt change. Here, 

 though the outer slopes of the hill are green and gradual, there are 

 rough black crags under the castle of distinctly basaltic appearance. 

 Round Schwalheim and Wisselsheim there are less prominent 

 exposures, but it is easy to ascertain that these eastern elevations 

 are of the same lithological nature. 



III. The Eock-Fokmations present. 



It is therefore evident that the three scenic features above referred 

 to have a definite geological meaning, and that the component 

 parts of the whole area may be classed under three corresponding 

 headings — 



A. The Palaeozoic Ridge. 



B. The Tertiary Strata. 



C. The Igneous (basaltic) Series.' 



Before proceeding to a study of the position of the salt springs 

 and borings it will be well to notice in somewhat greater detail the 

 characteristics of these different formations. 



A. The Palceozic Ridge. 



As has been already observed, the Palfeozoic rocks are of 

 Devonian age; a series of flaggy, more or less ferruginous, altered 

 sandstones, grits, and * quartzite.' They are evidently of sedi- 

 mentary origin and belong to the 'Taunus-quarzit' group; over- 

 lying the ' Sericit-schiefer,' but stratigraphically below the other 

 members of the Devonian system. Fossils are apparently absent, 

 though some obscure plant remains are said to have been found near 

 the Winterstein. The strike is N.E.-S.W., and the dip varies from 

 28° S.E. to 72° or more in the same direction. It is not probable 

 that the student will meet with any other form of Paleozoic rock in 

 the neighbourhood, but it he has an opportunity of consulting the 

 geological map he will find certain other formations recorded. 

 Thus the ' Stringocephalen-kalk ' is mapped as occurring near 

 Hasselheck. I have been unable to find it there, and in suggesting 

 a doubt as to its presence I am glad to find I have the support of 

 Professor Wittich. The ' Orthoceras-schiefer ' are similarly marked 

 as cropping out by the Teich and north of Nieder Morlen, but 

 I have not been able to identify them in either locality. The 



1 Throughout this paper the Post- Miocene deposits are left out of consideration. 

 There is doubtless much interesting matter awaiting study in this direction, and 

 Herr Professor E. Wittich (see list of references at end) has studied what he regards 

 as Pliocene and Glacial beds in the neighboui-hood. 



DECADE IV. — VOL. VII. — NO. VIII. 23 



