438 D. MACKINTOSH ON THE ERRATIC BLOCKS OF 
diameter, and at the same time making reasonable allowance for 
those that have been ‘‘ massacred,” reinterred, or not yet disinterred, 
I think it will follow that the Criffel-granite boulders of this ter- 
minal concentration can only be numbered by many thousands. If 
we make allowances for flattening and striation through being 
dragged by horses* to their present resting-places, very few of the 
boulders can be said to be glaciated. Their rough, subangular, and 
often angular shapes forbid the idea that they were pushed forward 
under a sheet of land-ice. They could not have been transported on 
the surface of the ice, because no one can suppose that an ice-sheet 
with its surface lower than the part of the mountain from which the 
boulders must have come could have moved as far as Wolverhampton 
(170 miles), and during the latter part of the journey up hill. It 
would he contrary to what we know of the purity of the interior of 
Antarctic and Arctic ice-walls and icebergs to suppose that so vast 
an array of boulders could have been carried in the middle of an 
ice-sheet. It may be suggested that land-ice might have brought 
the boulders on its surface as far as the peninsula of Wirral, and 
that they were then transported by icebergs broken off from the end 
of the ice-sheet; but while the peninsula of Wirral furnishes no 
evidence of a change in the mode of transportation, it can be shown 
(see VI. § 1), from a consideration of relative levels, that icebergs could 
not have retransported the boulders as far as Wolverhampton. 
9. Scottish * Greenstone” Dispersion.—At Dawpool, on the coast 
of the estuary of the Dee, the New North Docks, Liverpool, and for 
some miles around, many very large and small boulders of a dark- 
coloured and often decomposing “greenstone” may be found. I 
have traced them as far east as the neighbourhood of Runcorn and 
Overton, and a little further south than Chester. At the New North 
Docks, Liverpool, nearly all the large boulders found during the 
progress of the excavations were ‘“‘ greenstone,” and many of them 
were much flattened and grooved. Fora long time I could not trace 
them to their parent rocks, having failed to see them on the first 
stage of their journey in any part of the Lake-district. I have 
lately been led by Dr. James Geike and Mr. Horne (of the Geological 
Survey of Scotland) to believe that they came from Kirkcudbright- 
shire or Wigtonshire. Some boulders of a rather different kind of 
rock (to which the term ‘“‘ greenstone” would formerly have been 
appled) are to be found associated with the Criffel-granite boulders 
around Wolverhampton 7. 
* One boulder in the late Mr. Mander’s bouldery, Tettenhall, required fifteen 
horses to drag it from Trescott. 
+ Professor Bonney has favoured me with the following remarks on a chip 
from one of the “ greenstone” boulders on the Dawpool coast :—‘ This slide 
is composed of triclinic felspar, augite, olivine, and grains of iron peroxide, 
probably magnetite. There are also a few small scales of brown mica, and a 
little of some zeolite. The felspar crystals are in very fair preservation, and 
rather smaller, as a rule, than those of the augite and olivine, which two 
together make up quite two thirds of the slide, and are not at all decomposed. 
There is no trace of a glassy residuum. ‘The rock is therefore a rather finely 
crystalline dolerite (anamesite of many authors). It is obviously hazardous to 
