30 ■ The American Geologist. •^"'^'' ^^*'^- 
dence there is for correlating it with the Meguma I do not 
know . 
All that can be said definitely at present, upon the subject 
of original extent, is that the character of the sediments gives 
no indication of the proximity of any natural margin, and the 
former lateral extent was probably much greater than now ex- 
posed, even were the strata straightened out and the folds 
eliminated. 
Evidence as to greater original thickness is of four classes, 
none of which gives definite quantitative results. The first 
is the extent of younger sediment composed of material which 
may have been derived from the Meguma. Xo measurements 
have been made which would justify giving figures on this mat- 
ter. But the area and thickness of the lower Carboniferous 
conglomerate in the eastern half of the province, where it is 
composed almost entirely of Meguma waste in parts, are both 
considerable. It is very noticeable at Gays River mines, Cold- 
stream, Colchester county, that the conglomerate contains a 
large amount of one rock not now found as a part of the older 
series — a dull red sandstone. The rest is readily traceable to 
the Meguma . This red of course may be Devonian ; but there 
is no evidence that it is, and the boulders at Gays River have 
evidently not travelled far. Again, there may have been an 
upper formation in the Meguma, now eroded completely away 
and preserved in these relics ; or the latter may come from a 
younger series below the Devonian, although wc know of none 
which answers the description. 
The second cla. s of evidence as to the former thickness of 
the Meguma is its structure. The folds are as sharp and well- 
formed at the present summit as at the bottom ; and. except at 
the extremities of domes, have no faults which appear to be 
consefjuent upon east-west folding while brittle. The whole 
appearance of the orogenic type displayed by the series indi- 
cates that the folds were made well down in the zone of plastic- 
ity, which later became one of plasticity and fracture. 
The third line of evidence is the dynamo-metamorphism, 
which will be discussed separately in a subsequent paper. It is 
as thorough at the top of the series as at the bottom, and of 
such degree as must have required no small depth of superin- 
