152 PROF. ANSTED, ON TERTIARY FORMATIONS OF SWITZERLAND. 



In conclusion, the Tertiary Geology of the South-West of Switzerland 

 may be said to be separable under three heads ; first, the great deposit of 

 Molasse, which appears, from all we can tell, to be of marine origin; secondly, 

 the fresh-water marls and lignite bands occurring in the Molasse, but very 

 local, and apparently near the upper part ; and thirdly, the overlying beds of 

 marl and limestone in the valleys of the Jura, which alone can be compared 

 with the better developed systems in other parts of Europe; but since, from 

 the general dip of the sandstone, that portion of it in the Jura valleys would 

 seem to have been the earliest formed, there is no reason why the overlying 

 beds there should be very much newer than the lignite near the Alps. The 

 period therefore to which the Molasse must be referred, still remains in 

 doubt. It also results from the dips and observations recorded, that the so 

 called great Helvetic Basin is in fact no basin at all, but a vast accumula- 

 tion of sandstone, formed probably upon an inclined plane, and then tilted 

 to a greater or less angle into its present position. The smaller valleys are 

 indeed true basins, but the structure of many of them, especially the most 

 Easterly, is a point, I think, yet to be determined. 



It is obvious that much remains to be done in determining the true 

 geological relations of the Molasse, its fossils, and the varieties of its dip ; 

 and I would especially direct attention to the limestone near the Southern 

 extremity of the lake of Neuchatel, which is the most promising of 

 any part of this tiresome formation. Should there be found here any 

 fossils, they must possess great interest; and I regretted extremely the 

 want of opportunity which prevented me from examining accurately 

 the whole neighbourhood. It is very accessible, being close to the high road 

 between Yverdon and Moudon, and certainly deserves the attention of any 

 geologist travelling in that part of Switzerland. 



Should anything I have said lead to the determination of this and other 

 points in Swiss Tertiary Geology, my object in bringing this paper before 

 the Society will be fully accomplished. 



D. T. ANSTED. 



Jesus College, 

 March 1841. 



