376 Professor Sedgwick and Mr. Murchison on the 



towards the northern plains ; and in the few traverses we made in that 

 direction^ we found the regular deposits so much concealed by masses of 

 horizontal conglomerate, like that of the accompanying sections (fig-. 6.& 9.), 

 as to give very little definite information. Their correct description can only 

 be attempted after a patient comparison of many parallel sections : for the 

 purpose, however, of conveying a general notion of these deposits, we may 

 briefly refer to some of the phenomena on the banks of the Lech between 

 Fussen and Schongau. 



The river, after emerging from the side of the chain at Fussen, runs for 

 some miles in a broad plain covered by the waterworn detritus of the moun- 

 tains, and then traverses for about ten miles, in a direction nearly due north, 

 a hilly region marked by low, irregular ridges of coarse conglomerate ranging 

 parallel to the chain. Though the beds are ill exposed in the greatest part 

 of this long traverse, we have evidence enough to prove — that they are 

 highly inclined and have an almost undeviating dip to the north — and that 

 the conglomerates (which give an impress to the whole character of the 

 country) alternate, here and there, with micaceous, sandy marl, and greenish 

 micaceous sandstone, hardly to be distinguished from the tnolasse of the Lake 

 of Constance*. There may be some unobserved faults and dislocations, pro- 

 ducing a repetition of certain parts of this system : but after every possible 

 deduction, its aggregate thickness must be enormous. 



At Lech Bruck (about twelve miles north of Fussen) we have the following 

 ascending section of a remarkable group of strata, which dip nearly due north 

 at an angle of about 60°, and occupy the bed of the river for three or four 

 hundred paces. 



1. Micaceous, flaggy sandstone, with traces of carbonaceous matter. 



2. Thick-bedded sandstone, with broken stems and carbonized fragments of plants, overlaid 

 by a bluish marl. 



3. Fine-grained sandstone, here and there passing into a conglomerate. 



4. Greenish grey, micaceous shale, with a seam of coal about three feet thick. 



5. Coarse-grained micaceous grit. 



6. Beds of coarse and fine grits surmounted by red and variegated marls, with a band of red- 

 dish, concretionary limestone resembling the cornstone of the old red sandstone. 



7. Hard, calcareous sandstone. 



These strata have no characters which are not found in secondary deposits; 

 and we did not see a single fossil in any one of them to assist us in deter- 



* A fine, greenish, micaceous standstone is extensively quarried to the north of Fussen, but we 

 do not venture to decide upon its relations, as we did not visit the works, and know of no mine- 

 ralogical means of certainly distinguishing the secondary and tertiary green sandstones of the Alps 

 from each other. 



