'lAMPLUGH : LARGER BOULDER? OF FLAMBOROUGH HEAD 405 
The proportion of far-travelled igneous and metamorphic rocks 
remains always low, its maximum barely exceeding 5 per cent., and 
yet it is a quantity which is never absent. 
Respecting these rocks, Mr. Barker's notes indicate that 
no inconsiderable number of those found at Flamborough (and 
presumably, therefore, elsewhere also) may have come from Scandi- 
navia, while others have been furnished by the northern and eastern 
parts of the English Lake district, and others again by the Cheviot 
Hills and the southern part of Scotland. 
The proportion of blocks from the Carboniferous system is, on 
the other hand, always high. And when, in addition to the rocks 
which can be recognized at a glance as Carboniferous, the basalts 
from the same system are considered, the proportion from that system 
in almost every case outnumbers, and generally greatly outnumbers, 
all the other rocks combined. 
With the definite and well-known trail of the Shap granite and 
Brockram erratics to guide us, we need feel no uncertainty as to the 
quarter whence these Carboniferous rocks have been derived. It 
is clearly the elevated region lying to the north-westward, eighty or 
a hundred miles away, which has been the main contributor, and the 
route must in most, if not in all cases, have been down Teesdale, and 
thence south-eastward along the coast. 
It is the Secondary rocks which form the unstable factor of the 
lists, both in proportion and in composition. In fact, were these 
Secondaries eliminated, the other differences would become very slight 
indeed. From the distribution of these rocks we gather the same 
lesson as from the study of the route taken by the Carboniferous 
rocks, that the Eastern Moorlands and the Wolds were not entirely 
overridden by the great ice-sheet, but that they formed a buttress 
upon which that mighty stream impinged. 
The striking low percentage of Secondary rocks on Flamborough 
Head demands explanation ; though perhaps, as already remarked, 
this inequality may be somewhat exaggerated in my tables by the 
omission of a few loose blocks of chalk. But when the general 
character of the ice-movement fi'om the seaward is taken into con- 
sideration, in conjunction with the fact of the considerable eastward 
