302 Professor Sedgwick and Mr. Murchison on the 



printed ; and it was resolved that they should, if possible, appear in one me- 

 moir, arranged in such a way as to show the relations of their several sub- 

 divisions to each other. Published in this manner, it was supposed that they 

 would be more instructive: and it seemed anomalous, that in the same Part of 

 the Transactions there should be two sets of communications — one intended 

 to explain or correct the other. 



Ag-reeably to this resolution, the authors were directed to rearrange the ma- 

 terials before them, and to place them, as far as they are able, in a natural 

 order. For this purpose they, in the first place, give such a sketch of the 

 structure of the Eastern Alps as may, they hope, convey a general notion of 

 the distribution of the great mineral masses of the chain, and show the nature 

 of the difficulties they endeavour to clear up in their detailed sections. They 

 then describe a succession of such sections, commencing with the secondary 

 and tertiary systems at the head of the Lake of Constance ; and proceeding 

 towards the east along the northern skirts of the chain, they notice, in order, 

 the deposits in the valley of Sonthofen ; the junction of the secondary and ter- 

 tiary systems at Nesselwang ; the section along the banks of the Traun, from 

 the mountains above Arzt to the plains of Bavaria below Traunstein; and the 

 sections through the iron-works of Kressenberg, and through the secondary and 

 tertiary groups north of the Untersberg. Taking the relations of the succes- 

 sive groups on the outskirts of the chain as a clev/ to explain still more difficult 

 phenomena, they then give detailed sections of the overlying deposits of Gosau, 

 Zlam, Windischgarsten, Griinbach, and Wand. Having by this general com- 

 parison endeavoured to vindicate the justness of their former conclusions re- 

 specting the age of the overlying deposits of Gosau, &c. ; they proceed to 

 describe the insulated basin of Haring, some deposits of lignite on the flank 

 of the Bavarian Alps, and some horizontal cretaceous and tertiary deposits at 

 Ortenburg, near the junction of the Danube and the Inn, The tertiary for- 

 mations of Styria are then described and compared with the newer formations 

 of the Vienna basin : and, finally, the general results, derived from a conside- 

 ration of all the facts detailed, are exhibited in a short summary. 



The largest portion of these descriptions is derived from the observations 

 of Mr. Murchison ; and the details respecting the valley of Sonthofen, the sec- 

 tion along the banks of the Traun, and the account of the deposits at Zlam, 

 Windischgarsten, Griinbach, Wand, and Ortenburg, are exclusively his own. 

 Both the authors are, however, to be held responsible for the opinions ad- 

 vanced in this memoir, as they entertain the same general views on the struc- 

 ture of the Eastern Alps, and have together reconsidered the evidence on 

 which the several conclusions are founded. — A. S. 



