e° Remarks on Rocks accompanying Anthracite. 
..*M. Beudant’s tertiary class can be only local, confined: 
to the basin of the north of France, and the south of Eng- 
land, as it consists of all the-strata that lie above the chalk. 
As there is no chalk in the United States, there can be no 
tertiary class, and in many other countries, such as Norway, 
Sweden, &c. I {ound a small band of chalk between Mos- 
cow and the Black sea, in Russia, entirely surrounded by 
alluvion. Chalk is a very rare rock and cannot possibly 
be considered as a good foundation for a class. 
REMARK BY THE EDITOR. 
The above communication was received a good while 
since, and ought to have appeared before—but owing to 
the editor’s ill health it was acéidentally postponed. 
Remarks on the rocks accompanying anthracite at Wilkesbar- 
re and elsewhere, by Pres. Maclure, in a letter to the Editor 
dated Madrid, dug. 20, 1822. 
I observe in your Journal’a description of the anthracite 
at Wilkesbarre, Pennsylvania, by Mr. Cist. In describing 
the accompaning rocks (the most essential part of Geology) 
he gives avery correct mineralogical description, but that is 
not sufficient to be comprehended by the SR ccnien geolo- 
gist; for all the aggregates, secondary or transition, have 
pretty much the same mineralogical structure ; but the po 
sition and relative situation decides the class and fixes the 
nature of the rock. The whole region about Wilkesbarre 
belongs to the transition class, and all the slate he describes 
with spots of mica, must be gray wacke slate. Aggregates 
of large rounded pebbles cemented by quartz, form the 
*V° Reudant gfe ea + ‘a ct : his Gres how- 
illier, and confounds it with the argillac cide of iron, found in : 
~“— = eet out of ich the greatest part of the English iron # 
te of iron rarely, if ever, occurs in — 
is found in transition recks, ano ption that there is some 
supposing Carpathian and A i 
priueipally of Gres houillier or coal measures. 
! in the United States for the study of geo 
ogy, that itis probable when its it, will be 
vishal Wp “thle ae its advantages are generally known it. 
