1868.] SANDBEKGER SECTION OF A WELL AT KISSENGEN. 5 



fixed, it follows that the strata overlying the above-mentioned Plat- 

 tendolomit, and ranging from a depth of 1590 ft. 9 in. to 1698 ft. 

 10 in., belong to the lowest part of the Bunter Sandstone ; while 

 those that immediately underlie it, at a depth of from 1740 to 2001 

 feet, must be referred to the upper region of the Zechstein. 



The limestones which were so repeatedly raised during the boring 

 caused the reference of the former series to the Zechstein ; but the 

 author states, as the result of his examination, that they differ in 

 all their relations from the deeper limestones occurring at 1698 feet 

 and upwards, and, on the other hand, correspond in none of their 

 characters with the Plattendolomit (the uppermost member of 

 the Zechstein), and that they therefore belong to the Bunter Sand- 

 stone. 



Limestones being particularly abundant in the lowest portion of 

 the Bimter Sandstone in Thuringia and in the district of Magdeburg, 

 and occurring even in two forms, viz. (1) as " Rogenstein," often very 

 coarse-grained, and (2) as close or fine-grained so-called "Homkalk," 

 the author concludes, from the comparison of a very complete series 

 of them, that the " Hornkalk " corresponds entirely in petrogra- 

 phical and chemical characters with the beds in question, — and also 

 that beds of rock-salt, analogous to those of Stassfurt or Schone- 

 beck*, cannot be reckoned upon in Franconia; for the strata in 

 which they lie are but slightly developed on the southern margin 

 of the Thiiringer-Wald, and at the best contain very little saline 

 matter. 



Below the Plattendolomit of the Zechstein, from the depth of 

 1740 feet to 1884 feet follow saline clays of red, bluish, aud brownish 

 colour, which appear to be traversed by lines of anhydrite, or of 

 white gypsum. Boiling water extracts from them a tolerably large 

 quantity of alkaline chlorides (one specimen of the red saline clay 

 yielded 3*21 per cent, of chloride of sodium with very httle chloride 

 of potash), and little of the sulphates ; they are evidently the prin- 

 cipal source of the saline contents of the Kissingen wells. 



The still deeper anhydrite, from 1884 to 2001 feet, is dirty bluish- 

 grey, very hard, and here and there contains druses, in which 

 crystals of the mineral appear to have been formed. 



At a depth of 2001 feet the boring was discontinued, in conse- 

 quence of the breaking and jamming-in of the chisel ; and the ques- 

 tion therefore still remains, whether the anhj'drite forms the base of 

 the salt-bearing beds of the Zechstein in Franconia, or whether it 

 is only an intercalated bed between an upper very poor deposit, 

 which owes its importance entirely to the mineral waters which derive 

 their salt from it, and a lower and richer rock-salt formation. 



That this is possible appears, e. g., from the fact that in the 

 Triassic deposits of Baden and Lothringen the salt-bearing portion 

 contains several divisions of the pure rock-salt beds, which are 



* A very complete meraoir on Schonebeck is that by C. v. Albert! in the 

 Zeitschr. d. deutschen geol, Gesellschaft, vol. xix. 1866, p. 373, which gives the 

 most striking proof of the rock-salt in question belonging to this series of beds, 

 as shown by many well-seeiions. 



