GEOLOGY 13 
in vain for fossils—searched so diligently, that probably now those who 
know them best would be most surprised to find recognisable organisms 
in them. Yet many of them seem less altered than rocks that in other 
formations are very fossiliferous. ‘There is no reasonable doubt that 
they are older than the earliest fossil-bearing groups—that is, they are 
pre-Palzozoic in age. 
They have a wide distribution in the North-east. Inland exposures 
are often obscured by surface drifts, but along the coast, from Cullen 
in the north to Stonehaven in the south, they are exposed in a section 
over seventy miles long. On the shore of the Moray Firth, from west 
of Cullen to Gamrie Bay, the rocks are laid bare, with few gaps, for some 
twenty-five miles. This section has been frequently described, the most 
detailed account being that of Prof. H. H. Read, who re-surveyed the 
ground recently for the Geological Survey. One of the interesting facts 
that emerge is that the Moray Firth group falls into two series, the 
western (known as the Keith Division) showing a higher grade of meta- 
morphism than the eastern (the Banff Division). ‘The two are separated 
from one another east of Portsoy by a definite structural break, known 
as the ‘ Boyne line.’ While the Keith division is generally accepted 
as a northerly extension of the Perthshire series, the Banff division appears 
to be unrepresented in Perthshire, perhaps even anywhere in Scotland, 
unless it may correspond in a measure to the Loch Awe group (S.W. 
Highlands). 
The metamorphic series is continued eastwards along the coast through 
Fraserburgh to Peterhead and thence southwards to Aberdeen, but the 
continuity is interrupted by blown sand-drifts and igneous intrusions. 
South of Aberdeen, these rocks build a continuous coast-line for fifteen 
miles—a fine section, though frequently inaccessible from land owing to 
the precipitous character of the cliffs. It consists of coarse gneisses, 
mica-schists, hornblende-schists, quartzose chlorite-schists and other 
types, interleaved with granite injections, penetrated by pegmatite dykes 
and felsite sills, by dolerite dykes and some amygdaloidal rocks, and 
carrying, in some belts, minerals of high-grade metamorphism like 
Sillimanite and Staurolite. The metamorphics terminate abruptly 
against the Highland Fault just north of Stonehaven. 
__ The rocks of the coast sections can be followed inland, still maintaining 
‘ the same general strike as the coast series, and with the same trend as 
their supposed equivalents in Forfarshire and Perthshire—from which, 
however, they are almost severed by the intrusive masses of the Grampian 
Granites. 
The Dalradian age of these rocks is not admitted by all: the more 
westerly members of the Keith group have been sometimes regarded as 
belonging to the Moines ; certain members of the Banff group have been 
correlated with the Lennoxians ; and by some, the whole sequence from 
Peterhead to Muchalls (Stonehaven) has, again, been referred to the 
group of the Moines. 
: The age, the metamorphism, the structural relations, the stratigraphical 
_ Sequence of these rocks are all still very obscure: their full elucidation 
promises to be another battle-ground of Scottish geology. 
