26 Boue^s Geological and Miscellaneous Observations. 



at the bottom blue clay with shells and sulphur covered 

 with sand and limestone with marine shells, and here and 

 there fresh water deposits. 



The basalt, or trap, forms in the Vicentin bed like veins, 

 and veins in the recent taicose schists, and in zechstein and 

 red marl. These last are altered in a most singular way 

 at their contact. The same rocks cut all the secondary 

 formation ; the former (the basalt) in true beds or coulees 

 between the green sand and the chalk, and alternates as 

 well as the shelly tuffas from two to six times with the 

 coarse tertiary limestone. But the most singular fact is 

 that of Predazzo in the Tyrol, where an immense projec- 

 tion of dolerite and granite passes through and rests upon 

 the secondary rock ; the juratic dolomite forms higher hills 

 but yet does not cover this igneous protuberance ; and at 

 tfie contact the dolomite is changed to granular primitive 

 limestone, and minerals have been produced here which 

 are in the undermost limestones. 



The dolerite passes gradually into granite, and a coarse 

 granite with schorl or with coccolite forms dykes in the 

 porpbyritic line dolerite. This was discovered by Marza- 

 ri. Von Buch is wrong in deriving the magnesia (of the 

 dolomite) from the porphyry, the dolomite is an original 

 deposit. This same augitic and porphyritic deposit forms 

 in the Vicentin dykes in the chalk, and covers also in part 

 the chalk, md yet there are mines of galena and blende in 

 small veins ! All the Fassa trap beds in Zechstein are 

 nolhiiig but this tertiary igneous rock, and are like beds, 

 or in columns in the juratic limestone. Jt is astonishing 

 that the errors on this point should so long have been over- 

 looked. 



In Switzerland there are two ?>"olasses, one is like the 

 red marl, like the Carpathic, what Beudant callg his Gres 

 houillcr; and the o!her is tertiary, and is divided into in- 

 ferior molasse with lignite, and superior with marine 

 shells. 



— Baron Ferussac's journal is going on with great success. 

 Humboldt is soon to publish a second edition of his geog- 

 nostical Essay. Beudant is printing a system of Mineralo- 

 gy. Maraschini has published a most excellent work oa 

 the Vicentin. 



