East of the Alleghenies the deposits are anthracite, while the bituminous fields occupy the southwestern section of the state.Ed.
The surface may or may not be coated with some bituminous material.
Soft or bituminous coals contain considerable organic matter besides carbon and mineral substances.
bituminous may be distinguished from subbituminous by the manner of weathering.
Taken generally, the coals are bituminous in the south-east and anthracitic in the north-west.
In that isle there are the bituminous springs which Herodotus has commemorated.
bituminous coal exists in great profusion in various parts of the Western Valley.
The coal is of two varieties: bituminous and semi-bituminous.
These sandstones, bituminous schists, and indurated clays, contain mercury both in the state of sulphuret and in the native form.
It exists in large masses in the bituminous schists of Idria.
1610s, from French bitumineux, from Latin bituminosus, from bitumen (see bitumen).
The Plain, wherein a black bituminous gurge Boiles out from under ground, the mouth of Hell. ["Paradise Lost," XII.41]