Mcgiiina Scries of Xora Scotia. — Woodman. 2<) 
Origin . 
Prc-Mcgnnia continent unknown. — Tlie Mc-fi^unia scries 
stands almost alone among the large stratified groups on the 
continent, in having no rocks visibly subjacent to it, in vertical 
or areal distribution. Neither bottom nor margin is known. 
The granites show no horses of a foreign and presumably older 
series. The conglomerates give little hint of what must have 
been a very large land mass. The schists of the Yarmouth re- 
gion were at one time regarded as subjacent to the Meguma 
series, but are not now so considered. In the east, Faribault 
says ('87, p. 146) "The base of the quartzyte group is char- 
acterized by the occurrence of coarse quartzyte and grit in cer- 
tain beds which, at the mouth of St. Mary's river, appear to be 
underlain by bluish-black and greenish siliceous slate holding 
small crystals of andalusite or staurolite." But no proof of the 
separateness of these rocks is given, and they may well be only 
a more highly metamorphosed part of the Goldenville forma- 
tion. Xor does the author show, either in the text or the map 
sheet (nos. 28, 29; Geol. Surv. Can., docs. 382, 383), that 
they lie at the base of the series . 
The southern, western, and part of the eastern margins lie 
under the sea, the original shore regions having of course long 
since vanished. The northern and part of the eastern margins 
lie under younger sediments. 
Problem of original dimensions: original extent and thick- 
ness. — Evidence as to the original dimensions of the series is 
circumstantial only, like that for several other factors in its 
history. Its lateral extent must have been much greater than 
at present . The only hint of the proximity of the pre-M'eguma 
land comes from the few conglomerates, chiefly in the west. 
None of these have been proved to be basal, hence cannot be 
used as arguments for the proximity of the shore at the begin- 
ning of sedimentation. At the east, the present strike of the 
series carries its northern contact clear of the south shore of 
Cape Breton ; and, unless its strata extend far to the north 
imder the Devonian, it is not to be expected that Meguma rocks 
would be fotmd on the island. A small circular area of this 
age is, indeed, mapped in southern Cape Breton (Geol. Surv. 
Can., doc. 203), occupying only about one-fourth of a square 
mile, and surrounded by pre-Cambrian rocks ; but what evi- 
