378 Professor Sedgwick and Mr. Murchison on the 



the preceding section occupy the banks of the Lech for some distance to 

 the north of Schongau ; but we did not follow the river in that direction, 

 and the plains stretching- northwards are nearly covered with the horizontal 

 conglomerates. The bands of marlstone and calc-grit alternating with the 

 marls and conglomerates of the Peissenberg hills, contain some well-pre- 

 served fossil shells ; and we found that coal had formerly been worked in the 

 lower strata of these hills at several places near the banks of the Ammer. 



Meagre as is the information conveyed by this traverse from Pussen to 

 Schongau, it is more instructive than any other similar section we are able to 

 offer; and it at least demonstrates the great, and almost incredible, thickness of 

 the newer deposits on the outskirts of the Alps. It further shows that lignite 

 is, by itself, no test of the age of any tertiary deposit; in as much as we have 

 on the northern skirts of the Alps, two, or more, courses of that mineral, 

 one in the lower and another in the higher part of the series, separated from 

 each other by vast sedimentary formations. Without assuming the former 

 continuity of distant deposits of lignite, we think it evident that they were 

 developed through a considerable extent of the lower tertiary groups, between 

 the Lech and the Inn : for, in addition to the localities above mentioned, we 

 find traces of them at Pensberg, a few miles N.W. of Benedict Bayern ; at 

 Tolz, on the right bank of the Isar; and at Parsberg, near Miesbach — all 

 which places seem to be nearly on the same parallel. 



A level was driving to the Pensberg coal when we visited that district in 

 1829 ; but we have not heard whether the works have been since prosecuted. 

 In a mass of bituminous and calcareous shale derived from the excavations, 

 we found many flattened or broken and a few well-preserved fossils, among 

 which were the following genera : Cyclas ? two species ; a transverse bivalve 

 resembling a Mya ; Cardium ; Venericardia (?) ; Cerithium or Potamides, and 

 Calyptrffia. 



The works at Tolz and Parsberg have been many years deserted ; we 

 however visited the latter locality, and found that the place where the lignite 

 bed had been last opened was in a deep ravine, called Sulz-graben, on the 

 left bank of the Leignach, about a mile south of the village. The coal is not, 

 however, confined to this ravine ; for it has been traced in several parts of 

 the tertiary hills, which range near the north end of the Tegernsee (parallel 

 to the ridges of secondary green-sand), and are traversed by deep gorges, 

 laying bare their interior structure. 



The sections at the Sulz-graben show the following groups in the ascend- 

 ing order. 



