THE 
GEOLOGICAL MAGAZINE. 
NEW SceRIES. IDECADE “lk VOR x. 
No. V.—MAY, 1883. 
Ore IL GAIN Ze) eA sy ee Cab IS. 
———— 
J.—Tue Secret or THE HIGHLANDS. 
By Prof. Cuartes Lapworrn, F.G.S. 
(Continued from p. 128.) 
(PLATE V.) 
VIIl.—Dificulties in the Local Stratigraphy of the Oldest Geological 
Formations of Britain. 
a those parts of Britain upon which all geologists are agreed 
with respect to the natural order of their ascending series of 
rock-formations, the stratigraphy is of a comparatively simple 
character. The beds are either gently inclined, or but slightly con- 
voluted. The rules by which the original sequence of the strata is 
worked out have been settled by common consent. The nature and 
effects of those physical accidents which have affected the rocks 
subsequent to their deposition have long since been almost ex- 
haustively worked out. The rules and conclusions thus developed 
are now-a-days part and parcel of the working material of every 
field-geologist worthy of the name. 
These undisputed British rocks are, generally speaking, of Neozoic 
and Upper Paleozoic age. They afford an abundance of fossils ; 
and, taught by the generally acknowledged truth of the maxim of 
William Smith, the stratigraphist, in those rare cases where con- 
tinuous sections fail him, calls in the aid of organic remains, upon 
which he relies with almost as much assurance as upon the clearest 
visible physical proof. 
But in proportion as we descend in the order of the British 
geological formations, the stratigraphical complexities increase; and, 
unfortunately, the means of unravelling these complexities begin 
to disappear in almost equal proportion. The strata grow more 
monotonous in their physical characters, and their fossils decrease 
most markedly both in abundance and variety. When finally we 
reach the Lower Paleozoic rocks, we find that in certain special 
regions (notably those of South Scotland, the Lake District, parts 
of Ireland, and Western Wales) their strata are intensely folded, 
crumpled, and often inverted. In these regions the stratigraphist, 
who has been trained among the newer and less complicated forma- 
tions, becomes bewildered and deceived. He follows of habit and 
necessity the rules he found so serviceable in the less disturbed 
regions. He groups his strata in grand physical masses, and he 
settles the probable inter-relationships of these major groups by 
their visible order of superposition. The more extended has been 
his experience in British Neozoic geology, the more irresistible 
DECADE II.—yOL. X.—NO. V. 13 
