LAMPLUGH : LARGER BOULDERS OF FLAMBOROUGH HEAD. 235 
Per centum, 
4 Qartzite and conglomerates, nndoubtedly Primary 0'8 
187 Basaltic rocks ... ... ... ... 37-4 
3 Gneissic and schistose rocks ... . 0*6 
4 Granitic rocks .. ... ... 0'8 
500 100- 
By combining the three Flamborough Head lists we obtain a 
total of 328 Boulders, which furnish sufficient grounds for comparison 
with the 500 from Tunstall. The following table contains the con- 
densed results of this comparison, and reveals an interesting differ- 
ence in the character of the two lists : — 
' 5. COMPARATIVE TABLE. 
Flamborough 
TunstaU. 
Head. 
Per cent 
Per cent. 
Carboniferous Limestones, including 
the " doubtful" blocks ... 
20-0 
22-8 
Sandstones and Grits, supposed to be 
Carboniferous ... 
39-0 
14-4 
Secondary Rocks ... 
0-3 
221 
Basaltic and other Eruptive rocks 
340 
37-4 
Gneiss, schist, gTanite, etc.... 
6-7 
3-4 
100-0 
1000 
This table shows at a glance that the Holderness boulders, 
while essentially agreeing with those of Flamborough, differ from 
them in the presence of a considerable proportion of secondary 
rocks. The fact that the former locality lies further within the area 
covered by Secondary strata has no doubt something to do with this 
difference, but is not in itself a sufficient explanation, since there is 
no known border to the rocks of this age at a less distance than sixty 
miles from Flamborough Head, a distance surely more than sufficient 
for the Secondary erratics to establish themselves. I think that the 
main cause of the difference is as already indicated, that the lower 
layers of the ice which carried the secondaries were deflected eastward 
and southward by the high cliffs of the headland. Further researches 
now being carried on will no doubt elucidate this point. 
