PilOCEEDINGS OF GEOLOQICAL SOCIETIES. 



191 



rOEEIGN INTELLIGENCE. 



M. G. de Mortillet has published* a map of the ancient glaciers of 

 the Italian flanks of the Alps, in which the former greater extension of 

 the glaciers in the quaternary period and their present retracted limits are 

 marked out. The space occupied by these glaciers extended to the valley 

 of the Stura, near to the Col de Tende, as far as the environs of Udine. 

 The author believes that the lakes on the southern flank of the Alps have 

 been scooped out of the soft rocks by the grinding action of the glaciers. 

 The resume his theories is, that after the last upheaval of the Alps 

 there were formed enormous deposits of horizontally stratified alluvium, 

 which attained great thickness. Tliese alluvial beds exist above and below 

 the la^rge Italian lakes ; over them repose the glacial beds, with striated 

 pebbles and unrolled erratic blocks. This deposit has been left by the 

 glaciers, which then advanced more or less over the plain. These glaciers, 

 in clearing out the great basins filled with the ancient alluvium, have 

 scooped the site of the present valley. They drove before them the mate- 

 rials which they brought down, and these were heaped up in their terminal 

 moraines. The alluvial beds deposited during the great extension of the 

 glaciers, have formed a continuation of the ancient alluvium, and during 

 the period of retreat the streams of water have deeply excavated the ante- 

 rior or older deposits. They have scooped longitudinal terraces, which 

 border their present courses, and have not been able to fill up the great 

 depressions which now are the lakes. 



An " Essai sur les Conditions generales des Couches a Avicul a contorta, 

 svir la constitution geologique et paleontologique speciale de ces memes 

 couches en Lombardie, et sur la constitution definitive de I'Etage Infra- 

 Liasien," by the Abbe Stoppani, has been published in Milan (4to, 1861). 

 It is divided into three parts — the first containing bibliographical notices, 

 or rather an historical resume of the study of the beds forming the horizon 

 of the Avicula contorta, followed by a description of the characters of these 

 beds, and an indication of their thickness. In England they appear to be 

 very thin ; on the northern flanks of the Alps they are some twelve metres 

 thick ; while in Lombardy they attain to eight hundred or a thousand feet. 

 Their geographical area is of considerable extent ; they are met with in 

 England, Ireland. Wurtemberg, Bavaria, Westphalia, Luxemburg, in 

 the departments of the Moselle and the Meurthe, Cote d'Or, Yonne. Ehone, 

 Cevennes, Savoy, Switzerland, in the Vorarlberg, and at other points in the 

 chain of the Alps as far as Hungary — everywhere forming a convenient 

 and decided band. The second part of the Essay gives a more special de- 

 scription of these Avicula contorta beds in Lombardy, where they have 

 previously been studied by Collegno, Escher, and Omboni. In the third 

 part the author shows that, on palfeontological grounds, these beds must be 

 placed in the Jurassic series, and that they are sufficiently important and 

 sufficiently clearly separated from the beds above and below them to form 

 a separate division, which he terms the Etage InfraUasien. He indicates 

 exactly the synonyms of other countries, the principal of which are the 

 beds of Koessen in Austria ; the " Bone-bed" and White Lias in England ; 

 the " Cloac " of Wurtemberg ; the sandstone of Helmsingen and of Lseve- 

 lange, in Luxemburg; the sandstone of Hettange ; the zone of Ammonites 

 jplanorhis and A. angulatus of M. Oppel ; the limestone of Halberstadt ; 



* Atti della Soc. Italiaaa de Sc. Nat. in Milano, 1861, t. iii. 



