Waller Keeping — On Columnar Sandstone. 437 



II. — On some Columnar Sandstone in Saxon Switzerland. 



By "Walter Keeping, B.A., F.G.S. 



(Late Professor of Geology in the University College of Wales.) 



ONE of the most beautiful examples of prismatic jointing that we 

 know of in a sedimentary rock has lately come under my 

 notice whilst travelling in N.E. Germany. 



In a series of lithological specimens exhibited in the Dresden 

 Museum to illustrate the Cretaceous Period is a tray of small sand- 

 stone columns remarkable for their great regularity of size and 

 sharpness of outline. By the favour of Herr Deichmuller (to whom 

 I am indebted for many other acts of courtesy and kindness) I 

 was directed to the exact spot in the Meissener Hochland, or ' Saxon 

 Switzerland ' as it is more commonly called, where they were found. 



On many accounts the Saxon Switzerland is interesting to the 

 student of joint structure. It is a beautiful country, made up for 

 the most part of the well-known Quader Sandstein, of Upper Cre- 

 taceous age — well exposed along the steep natural cliffs of the Elbe 

 E.iver and in the numerous quarries along its banks. The rock is a 

 rather thick-bedded pale yellow sandstone, usually with casts of 

 fossils, readily worked with the hammer and chisel. It is well cut 

 up naturally by two sets of joints running at right angles to one 

 another, which are so regular as to divide it conspicuously into large 

 cubical blocks — on this account the name ' Quader ' was given to the 

 formation. According to A. von Gutbier 1 the joints are very persis- 

 tent in direction throughout the whole district of the Quader Sand- 

 stone hills, running from N.W. to S.E., and N.E. to S.W. respec- 

 tively. Further up the Elbtbal and in its tributary valleys this 

 cubical jointing is even more striking. Looking, for example, across 

 the Amselgrunde to the opposite cliff, we have presented to us the 

 appearance of a colossal wall of regular, gross' masonry about 500 

 feet high ; and, again, all those extraordinary and characteristic 

 features of this remarkable country — the deep narrow chasms and 

 ravines, perpendicular cliffs, sets of pinnacles and outstanding 

 columns — have for their existenzgrund this same regular, cubical 

 jointing. 



But leaving these more varied and picturesque parts, and turning 

 southwards up the country from Schandau, we come to the hill 

 known as Gorischstein, where occurs that particular prismatic sand- 

 stone which it is the purpose of this paper to describe. It is curious 

 how little known this section is. I have only been able to find a 

 single account of it in German or English literature, namely, that by 

 von Gutbier already refeiTed to above. 2 



The quarry is on the east side of the hill called Gorischstein, at 

 a height of 1150 ft. above the level of the sea. It is but a small 

 opening, no longer worked, which may be detected by the basalt 



1 Geognostische Skizzen aus der Sachsische Schweiz und ihrer TJmgebung, 1858, 

 pp. 30—31. 



2 I am indebted to Herr Deichmiiller for an account of this description by A. von 

 Gutbier. 



