Structure of the Eastern Alps. 325 



tinged green by disseminated particles of green-sand ; others are red and fer- 

 ruginous ; and some of the grey and nearly compact limestone contains balls 

 of pyrites. Above these fallen masses are some compact^ &i'Gy beds of lime- 

 stone containing several fossils, among which are large ribbed Terebratulae, 

 Oysters, and Pectens. Over the preceding is a sandy bed, the lower part 

 black and calcareous; the middle part of a rusty brown colour, highly ferrugi- 

 nous, and passing, here and there, into a true htematite forming a subordinate 

 bed about four feet thick, which has been extensively worked for use. The 

 upper part passes into a beautiful green-sand, full of Nummulites, and is sur- 

 mounted by alternations of black shale and limestone. 



This whole system dips nearly south, at an angle of 30° or 40°, and seems 

 to plunge under the great, contorted precipices of the Stauflfen, which are also 

 carried, with an inverted dip, towards the centre of the Alps. As we found 

 no indications of great faults, nor any thing in the suite of fossils to contradict 

 the arrangement, we considered the nummulitic and iron-stone beds as form- 

 ing a part of the newer, secondary groups of the Alps ; probably about the 

 same age with a portion of the chain, containing the ferriferous, nummulitic 

 beds of Sonthofen. From Haslach to Obersdorf no section was observed ; but 

 in the gorge above the latter place, are beds of grey, indurated marl and calca- 

 reous shale, of black shale, and of green-sand, alternating with a few bands of 

 sandy, veined limestone ; the whole dipping south at an angle of 70°. In the 

 village are some ill exposed beds of blue and red, impure, sandy limestone, con- 

 taining many Nummulites. We consider these beds as secondary : for those 

 in the gorge exactly resemble many of the strata of the green-sand and cre- 

 taceous series of the Alps ; and the nummulitic limestone may be only a repe- 

 tition of the secondary, nummulitic rocks of Haslach*. For about half a mile to 

 the north of Obersdorf, all the beds are covered with transported materials, 

 washed down from the nearest mountains ; but the numerous blocks of green- 

 ish, micaceous sandstone and of conglomerate, prove that the tertiary system 

 cannot be far off. Further north we found a quarry, in which the beds 

 dipped S.W. 75°, and gave the following section : 



1. Friable, micaceous, slaty sandstone, much charged with carbonaceous matter, and with 



stems of carbonized plants at the partings of the laminas 2 feet 



2. Coarse calc. grit, passing into millstone; outside brownish, inside greenish blue . . 5 feet 



3. Bands of micaceous sand with coaly matter 1 f*^"t 



* The details of this transverse section were read to the Society as they are now printed, not 

 long after our return from the Alps in 1829 ; yet it has been erroneously stated (both in British and 

 Foreign Journals), that we had described the deposits of Haslach and Sonthofen as tertiary. 



