44 Geology of Massachusetts. 
Scotia, with the rocks of the Connecticut valley, and they can hardly 
be distinguished from each other. 
As to anthracite coal, it seems to occupy a wider range among 
the rocks, than genuine bituminous coal. Generally, however, the 
former occurs lower down in the rocks—that is in older rocks—than 
the latter. Sometimes it is found in what are called transition rocks ; 
and sometimes in the primitive. In this country it is found in both 
these classes of rocks. We have inthe United States, at least three 
extensive deposits of anthracite: the largest isin Pennsylvania; the 
next largest in Rhode Island; and the smallest in Worcester. I have 
examined them all, and have come to the conclusion, that all the 
rocks containing this coal, are at least, as low down in the series as" 
the transition class: and I am rather of the opinion, that they all lie 
below the Independent coal formation of Europe; I mean on the 
scale of rocks. I suspect that the Pennsylvania anthracite occurs 
in the higher beds of the graywacke, perhaps even in the millstone 
grit, and the Rhode Island anthracite, in the lower beds of the gray- 
wacke. ‘There is no geological connection between the Rhode Is- 
land and the Worcester coal, as Dr. Meade and others have suppo- 
sed. By inspecting the Map, the two localities will be seen to be 
separated by granite and gneiss, from twenty to thirty miles across. 
The Worcester coal occurs in an imperfect kind of mica slate. It is 
what Humboldt calls transition mica slate: for a few miles north, it 
passes into distinct argillaceous slate. Following the range south 
from Worcester, it becomes more decidedly micaceous, and proba- 
bly there forms a bed in gneiss. Indeed, in Dudley, I saw the same 
rock surrounded by gneiss, and highly impregnated with anthracite. 
The bed of anthracite in Worcester, is about seven feet thick, 
and has a moderate dip to the northeast. It has been explored only 
a few feet, and the operations are now suspended. ‘To continue them 
advantageously, it will be necessary to go down the hill, and remove 
the soil so as to find the lateral outcrop of the bed, in order to avoid 
an accumulation of water. ‘This work has been already commenced. 
The Rhode Island beds of this coal were opened several years 
ago, before the value of it was justly appreciated by the community. 
The sales not being brisk, the works were abandoned, and have 
never since been resumed; so that on account of the rubbish, I 
was unable to ascertain the width of the beds. I have always under- 
stood, however, that there was abundance of coal. The beds are 
less favorably situated for working, than that at Worcester. 
