REPORT ON GEOLOGY. 
397 
menclature adopted by Mr. Eaton, and his subdividing a single 
formation, that of transition limestone, into many members, of 
which some were absurdly identified with the English lias, &c.; 
but more recently Mr. Featherstonhaugh, a geologist eminently 
qualified from his intimate acquaintance with European forma¬ 
tions, to advance those comparative views which demand the 
principal attention in our science, has undertaken a philosophi¬ 
cal journal in which these will be especially attended to ; he has 
also presented us with a correct table of the correspondence of 
the American and European formations, from which it appears 
that in the regions west of the Alleghany, nothing newer than 
the carboniferous series has yet been found ; the saliferous 
sandstone appearing, as an equivalent to our old red sandstone, 
to under-lie these *. 
Bigsby has ably explored the geology of the great Canadian 
lakes. This district principally consists of transition limestone; 
indeed the line of junction of this formation and the primitive 
rock throughout the whole northern extremity of America is 
accurately marked by the great chain of lakes, the primitive 
zone ranging along their eastern, and the transition along 
their western borders. Franklin’s celebrated expeditions have 
made us acquainted with all the arctic portion of this tract; and 
Giesecke and Scoresby have explored the nearly contiguous 
and equally inhospitable shores of Greenland; the American 
expeditions to the source of the Mississippi have made known 
the structure of the great central valley, and enabled James to 
continue Maclure’s sections as far as the Rocky Mountains f. 
Burkart and Sartorius have published a geological map and 
Memoirs on Mexico J. 
On the east of the Alleghanies, in New Jersey, formations 
which appear from their character and fossils equivalent to 
the gait of our cretaceous group, have been described by 
Mr. Moreton. I suspect, from ancient notices in Woodward, 
* In this there is nothing that ought to surprise geologists; the saliferous 
character appears common to rocks of every age, and no view can he more 
narrow and incorrect, than one which should regard it as restricted to the pce- 
cilitic sera. We have long been acquainted with saline springs in our coal mea¬ 
sures; in the more recent secondary rocks, we find the salt of the Alps chiefly 
in the midst of the oolitic series. The very modern tertiary clays of Sicily and 
the Sub-Apennines are saliferous ; and Boue considers the salt deposits of Tran¬ 
sylvania as of the same age ; the salt of Wielilzka is also in the tertiary formation. 
f At St. Louis on the Mississippi is a limestone with impressions, vulgarly 
referred to human footsteps. From the representations of these in Silliman, I 
should conjecture them to be casts of a large Perna, in which case this lime¬ 
stone may be analogous to our oolites. 
X Hence it appears that near Catorze red sandstone occurs covered by lime¬ 
stone containing Ammonites. 
