104 
THE GEOLOGIST. 
d'Encombres, in Savoy. By their researches in the geology 6f this 
country the author, with his brother and M. Bellardi, confirms the 
conclusion they arrived at in the year 1848, that the anthraxiferous 
formation of the Alps belongs to the Liassic age. Perhaps no other 
stratigraphical group has given rise to so much discussion as the one of 
which we now speak. The presence of coal and anthracite in the 
limestone-formations of the Alps long ago attracted particular attention 
to these strata. "What would our English geologists have thought, in 
1830, had they observed a seam of anthracite or coal imbedded in the 
white chalk of Dover cliffs ? Would it not have led to a strict 
examination of the stratigraphical relations of this chalk, and a more 
minute investigation of its fossils ; more especially if these were broken, 
cemented together, and difficult to determine, as they are in the Col 
d'Encombres ? That is precisely what has taken place regarding the 
Alpine strata; and since the year 1830, or thereabouts, up to the 
present time, they have been shifted about on geological tables and 
maps, from the white chalk to the coal-measures, from these to the 
white chalk again ; from the latter they have travelled to the Jurassic 
formations, to be finally* fixed in the Lias. Studer, Brongniart, 
Brochant, and D'Omalius, have all striven to solve this problem ; but for 
the elucidation of the discussed points we are mostly indebted to the 
admirable labours of M. Elie de Beaumont, who first got a glimpse of 
the real nature and position of the Lias strata of the Alps. 
The list of fossils from the limestone of the Col d'Encombres shows 
in all 63 species, of which 35 only can be specifically classified by the 
examination of fossils already known. Of these 35 belong to the 
superior, inferior, and middle strata of the Lias, with the exception of 
four, which are attributed by M. Sismonda to the stratum known as 
the Inferior Oxfordian bed. A remarkable circumstance, which 
deserves especial notice is, that from Professor Sismonda's account, the 
fossils which modern palasontologists look upon as belonging to different 
strata, are, in the Lias of the Alps, all found in one bed. Thus, at 
Col d'Encombres, all those belonging to the three Lias beds are found 
in one single stratum. 
* It is impossible to regard tliis -vexed question as definitely settled, even after 
these late researches of MM. Sismonda and Bellardi ; for we must not forget that 
M. Favre, and other equally talented and experienced Geologists, still consider 
that distinct Liassic beds are intermixed, by inversions, in some cases, with true 
Carboniferous beds, in these Alpine Anthraxiferous sti ata ; although some refer 
the whole to the Jurassic series, and others place them all in the Carboniferous. — 
iiD. OF GliOLOGlbT. 
