358 Professor Jameson’s Gcognostical Description 
others, was traversed by cotemporaneous veins of flesh-red com- 
pact felspar, or it contained the same mineral in imbedded 
masses, varying from an inch to upwards of a foot in diameter. 
These veins and imbedded masses were sometimes unmixed with 
the greenstone at the line of junction ; in other instances there 
were intermixtures and transitions of the one into the other, 
and not unoften branches or veins appeared shooting from the 
imbedded masses and veins into the surrounding greenstone, 
and from the greenstone into the imbedded masses. These 
facts prove the cotemporaneous formation of the felspar and 
greenstone, because any two rocks which are intermixed at their 
line of junction, and mutually penetrate each other in the form 
of veins, must have crystallised at the same time. 
The greenstone in the quarry just opened on the north foot 
of the hill, has the same general characters with that in Marshall’s 
Entry, and at the Custom House. In some places it is traversed 
by veins of greenstone, varying from a few inches to three feet in 
breadth. Some of these extend only a few feet, and their 
depth is not greater than their length ; others extend for se- 
veral fathoms, when they at length terminate, and these 
wedge out or terminate below, a few feet from the surface. 
Iron-pyrites is abundantly distributed through the green- 
stone, and sometimes also calcareous-spar. These two minerals 
also occur in the sandstone strata, which are traversed by the 
vein or dike of greenstone. The fact of the greenstone and 
sandstone, containing the same imbedded minerals, would seem 
to intimate that they are of simultaneous formation. 
The greenstone of the great vein, as it appears in the quar- 
ry (now filled up) beyond the Restalrig road, offered several 
fine examples of lateral veins shooting into the adjacent sand- 
stone, and some of these were parallel with the strata, forming 
beds three feet thick. The sandstone, where in contact with 
the greenstone, was highly crystallised, and in hand specimens 
nearly resembled the quartz-rock of primitive districts. 
The greenstone of Albany Street is in the form of a vein, from 
two to three or four feet thick, and which cuts across strata of the 
coal-field. For several yards it is bounded by bituminous shale, 
which has the usual characters of that mineral, both where it 
is in contact with the greenstone and at a distance from it. 
