Structure of t\e Austrian AIjjs, fyc. 1 03 



If it be asked in what part of the secondary series we place 

 the salt deposits above described, we are unable to give any 

 very definite answer to the question. In the limestone beds 

 associated with the salt are many fossils ; among them are Am- 

 monites, of which the concamerations are marked by simple or 

 undulating lines, and Orthoceratites. Both these fossils might 

 be supposed to indicate strata older than any part of the oolitic 

 series. Along with them are however near Hallein, oval Am- 

 monites, and spheroidal masses resembling organic remains of 

 the green-sand; also several casts of shells resembling oolite 

 fossils, and a singular body, found in our Kimmeridge clay, to 

 which the name Tellinites solenoides has sometimes been given. 

 At Aussee, in the beds of limestone containing the saliferous 

 marls, there are, along with other fossils, corallines of the ge- 

 nera Tubipora and Astraea, and Pentacrinites. On the whole 

 we are disposed to place the salt formations of the Alps high 

 in the oolitic series. 



The preceding conclusion might appear strange to one who 

 had only studied English geology; but it cannot now be con- 

 sidered anomalous, as recent discoveries have established the 

 existence of salt among rocks of almost all ages. In the Cri- 

 mea it is said to be daily accumulating in inland lakes. In 

 Poland it probably exists among tertiary deposits. In the 

 Austrian Alps we have placed it among the upper oolites. In 

 Switzerland Mr. Bakewell places it in the lias. In Wirtem- 

 berg Alberti has proved it to be both in the Keuper and Mus- 

 chel-kalk. In England, though all the great salt mines are in 

 the new red sandstone, there are two or three copious salt 

 springs in the coal-measures. Lastly, in certain parts of the 

 United States, salt springs are stated by Mr. Featherstone- 



haugh to issue from old transition slate rocks*, 

 o 



6. Younger Alpine Limestone. 

 Under this designation we include all those portions of the 

 northern secondary chain which are superior to the saliferous 

 deposits of the Alps. As we were unable to define the upper 

 limits of these deposits, we are necessarily unable to define 

 the lower limit of the formation we are now attempting briefly 

 to describe. We, however, suppose that it commences some- 

 where in the middle or upper system of the oolitic series; and 

 it terminates on the outskirts of the chain, in ridges of indu- 

 rated shale, sandstone, and limestone; in some places contain- 

 ing many characteristic fossils, and now supposed, by most 

 of the geologists who have visited the region, to be the equi- 

 valents of the green-sand and chalk. 



* See Phil. Mag. and Annals, N.S. vol. vii. p. 200.— Edit. 



Our 



