11 
each epoch are not more decidedly characterized by dissimilarity in 
their relationship to the associated sedimentary rocks than by dif- 
ferences in their composition. 
The traps of the first epoch occupy the northern portion of the 
county from Stratheden to the estuary of the Tay, constituting the 
eastern extremity of the Ochils. They appear to be coeval with the 
grey sandstone (Arbroath pavement), and to rest upon, as well as to 
be variously associated with the old red sandstone, and to be covered 
by the yellow sandstone which supports the mountain limestone. 
Viewed on a great scale, they consist of amygdaloids containing ir- 
regular masses of porphyry, clay-stone, clink-stone, compact felspar, 
green-stone, and trap tuff: they also contain thin layers of slate- 
clay and grey sandstone. ‘The whole of the igneous rocks are de- 
cidedly stratified ; and though the beds are thick and variously bent, 
they have, in general, the same dip as the superior and inferior sedi- 
mentary formations. The materials of which they are composed, 
Dr. Fleming conceives were spread out under water, partly as lava 
and partly as ashes; and that several of the peculiarities of rocky 
structure have been produced by corpuscular action. 
Two vertical greenstone veins traverse this group in an easterly 
direction. One of them may be traced along the north side of the 
Ochils from the neighbourhood of Newburgh by Norman’s Law to 
Luthrie, a distance of nearly six miles: the other, observable at 
Alva and Dollard, on the south side of the Ochils, may be traced 
nearly forty miles by Monymeal to Hilton Bridge, north of Cupar. 
Several cross veins of greenstone and felspar likewise occur. 
The trap rocks of the second epoch form the southern margin of 
Stratheden, and may be considered as constituting a ridge parallel 
with the Ochils, from near St. Andrews to Stirling; but several 
branches or patches of the same age have been observed in the 
counties on the south of the Forth. ‘These traps consist almost ex- 
clusively of greenstone, which in a few instances is earthy and 
amygdaloidal. ‘They cover, in many places, the lower beds of the 
coal-measures; on the East Lomond they are intermixed with the 
mountain limestone; and at Wemyss Hall Hill, south of Cupar, 
they overlap the limestone, and are in contact with the yellow sand- 
stone. 
These two groups of trap rocks, the author is of opinion, were 
produced while the associated strata of old red sandstone and coal- 
mheasures were horizontal; and that they have undergone, equally 
with the sedimentary formations, the movements which gave the 
strata of the Ochils and the ridge south of Stratheden the southerly 
dip. He is also of opinion, that the greenstone of the second group 
may have furnished materials for the great veins, which traverse the 
older one. 
The traps of the third epoch occur chiefly along the shores of the 
Forth, and in the higher coal-measures. They consist of basalt with 
olivine, amygdaloid, greenstone, wacke, and trap tuff; and they fre- 
quently contain fragments of limestone, flinty slate, slate-clay, bitu- 
minous shale, sandstone, and coal. They appear to have been pro- 
