﻿MM. SCHLAGINTWEIT ON THE ALPS. 



21 



the far greater slope of the walls is not sufficiently distinguished from 

 the more gentle inclination of the basin itself. The extent of these 

 basins is very considerable ; the largest, among which the firnmeers 

 are especially to be remarked, attain to half a square mile [German] 

 and more. 



Behind and at the sides they are enclosed by crests that surround 

 them in the form of the segment of a circle, subject of course to 

 much irregularity. Forwards they pass into narrow, extended val- 

 leys ; the transition being either gradual, or, as in most cases, rather 

 sudden. This narrow valley or dell [Thalenge] opens into a second 

 open basin, having very often a breadth of 2000 to 3000 feet 

 [French] . This continual succession of wide basins and narrow dells 

 is very conspicuous in all the transverse valleys of the Alps, and 

 have already been noticed in the valleys of the Aar, Linth, Reuss, 

 Gastein, &c, by Saussure, L. von Buch, Escher, Studer, and others. 

 Similar basins and circus-valleys are found in all the Alpine ranges, 

 and in the Pyrenees, the Jura, and other mountains, and they have 

 been noticed by Hutton and Playfair in England ; their examination, 

 therefore, must have a very general interest. 



Transverse Valleys. — Fully to exemplify these phsenomena the 

 author gives a copious detailed account of the following cross-valleys : 

 — 1. The Oetzthal, with its seven basins, illustrated by a woodcut 

 profile. This is described (p. 201) as opening into the longitudinal 

 valley of the Inn, five or six miles [German] above Innspruck, by a 

 narrow gap in the mica-schist mountains of the right bank. The 

 great volume of the water of the Oetz alone shows that there exists 

 an extensive valley behind this narrow cleft. The valley is composed 

 of a series of great basins ; the mountains, retreating mostly on both 

 sides and less frequently merely on one side, enclose wide level valley - 

 bottoms. These basins are connected in two ways ; either, from a 

 sudden subsidence or depression of the floor of the valley, a high 

 precipice divides them, or there occurs a longer interruption by means 

 of a ravine. The last is here more common, whilst we find the sud- 

 den depressions more developed in the Tauern Alps. 2. The Moll- 

 thal and its three basins, with a profile ; and 3 . The Fuschthal, 

 with its three basins. The interesting basins of the Gastein, noticed 

 by Von Buch, are also described (p. 207). 



Longitudinal Valleys. — These long-valleys are very numerous in 

 the Alps, and possess a similar alternation of basins and ravines as 

 that so constant in the transverse valleys. This character however 

 suffers certain modifications, owing to the great longitudinal extension 

 and the less height and inclination of the former. Special exam- 

 ples of their most important phsenomena are given in detailed de- 

 scriptions of the longitudinal valleys of the Drau and Rienz, which, 

 properly speaking, form one great valley (the Pusterthal) dividing 

 the long chain of the crystalline slates in the Tauern Alps from the 

 southern limestone Alps. * 



In the Alps it is sometimes rather difficult to define the charac- 

 teristics of a longitudinal valley. It would be a great mistake to 

 expect that these valleys must always run parallel to the chief longi- 



