Structure of the Eastern Alps. $23 



don of the younger Alpine limestone : it is therefore possible, that some of the 

 lowest fucoid grits and shales, may descend into the oolitic series. In a part 

 of the g-reat Vienna promontory they alternate with thick masses of limestone, 

 which, in our visit to that portion of the chain in 1829, we were unable to 

 separate from the older, secondary system of the Alps. Dr. Boue may, there- 

 fore, be correct in classifying a portion of these fucoid grits and shales with 

 the upper Jurassic formations : but we repeat our conviction, that in the 

 greatest part of their range along the flanks of the Austrian and Bavarian 

 Alps, these fucoid grits are completely subordinate to, and form a part of, the 

 green-sand series. 



8. All Deposits superior to the Chalk, comprehending several, distinct, 



tertiary Groups. 



The accompanying map * will show the general distribution of these de- 

 posits, which, with very limited exceptions, we shall not attempt to describe 

 in detail. A transverse section at the head of the Lake of Constance, 

 shows the position of a great succession of the newer deposits, which there 

 begin to conform to the type of the series in its range westward through 

 Switzerland. The sections at the eastern termination of the chain through 

 the plains of Styria, also give a long succession of tertiary groups ; but, in 

 general, the most important parts of the succeeding details, are confined to 

 the phenomena exhibited at the junction of the former group (No. 7.) with 

 the great tertiary system, which sweeps down from the foot of the Alps to the 

 plains of the Danube. 



The preceding account of the general structure of the Eastern Alps, has 

 been given as an introduction to the facts, exhibited in a series of detached 

 sections, the meaning of which could not be fully understood without it. If 

 our slight sketch serve in any way as a help towards a more detailed and per- 

 fect classification of phenomena, avowedly of great difficulty and obscurity ; 

 and if it should induce any geologists of this country to visit the regions we 

 describe, and become acquainted with the researches of the authors to whom 

 we have referred — our purpose will be more than answered. 



* PI. XXXV. 



2t2 



