at the Don and Tamar Rivers. 99 
I said before, that a strip of igneous rock, of which these 
points are spurs, skirts the coast on both sides of the Mersey 
River; and there is every reason to believe that, like most of 
the higher and more massive ranges inland, with which it is 
connected, it overlies sedimentary rocks. Having “ passed 
the ubicon,” a similar series of low dunes or sand-hills, 
with extensive flat beaches, recur, stretching to the foot of 
the Asbestos Hills, where the transition clay-slates present 
themselves in a nearly vertical position, rising from the sea 
level into mountain masses, having their planes of stratifica- 
tion variously bent and contorted, and crossed and re-crossed 
in every imaginable direction with veims of ferruginous 
matter and quartz. ‘The two headlands, known as “ Badger 
Head,” and ‘‘ Little Badger Head,” are of this structure and 
composition. Between West Head and Badger Head there 
is a long, flat, sandy beach, hedged in with high dunes, 
behind which there stretches along the eastern flank of the 
Asbestos Range a valley, chiefly formed in the sedimentary 
beds succeeding to the slate, and at some places in the clay- 
slate itself. The clay-slates usually, from the large portion 
of siliceous matter intermingled, yield but a cold, meagre, and 
ungenerous soil. Nor is thisvalleya marked exception, though 
at some places, where limestone comes to the surface, patches 
of desirable land with good herbage do exist. Many of the 
undulations look as if the surface had been sown with 
fragments of quartz. As in the case of the embouchure of 
the Mersey and of the Rubicon, the entrance of the Tamar 
River is guarded on either side with heavy masses of eruptive 
rock. From the West Head to Whirlpool Reach a chain 
of low rounded hills of greenstone, though interrupted by 
the intervals of the “West” and “ Middle’ Arms of the 
estuary of the Tamar, and broken by vallies of denudation, 
is still traceable, and to the south of Middle Arm tolerably 
H 2 
