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breaks on a rocky coast. These Tertiary gravels are, therefore, probably of 
marine origin As the land continued to rise, the sea would recede 
further west ; and the rivers being increased in size and power, subaerial 
degradation would proceed more rapidly. The channels of the rivers would 
be continually deepened, and the whole surface of the land gradually lowered 
to adapt itself to the increasing fall of the rivers What was the 
exact configuration of the country at the time of the first outbreak of the 
basalt lavas geological evidence fails to tell. That part only which has been 
sealed up under the lava sheets has been preserved to the present day, and its 
shape is being gradually restored by the workings on the £ deep leads.’ The 
results of these subterranean explorations tend to show that most of the country 
now covered by lava sheets, and forming in places main lines of water-parting, 
was at that time near to, or part of the principal drainage channels, and that 
the trend or fall of these old rivers agreed approximately with that of their 
nearest modern equivalents .... The. flora of. the period, to judge 
from the number and variety of leaves entombed in the Eocene pipeclays, was 
rich and diversified. The fossils are chiefly leaves of herbs, trees, and ferns, 
some having fruit, and a blossom delicately preserved, . . . . . At a time 
then when the physical features of the country were somewhat similar to 
what they are now, and its surface, probably some 20 or so feet higher than 
at present, was covered with an Eocene flora, volcanic energy revealed itself in 
the first eruptions of basalt. The hard rocks of the quartz-porphyry, felstone, 
and granite, were rent open ; and, where the volcanic forces became central- 
ised, small cones were thrown up composed of comminuted fragments of the 
underlying rock and scoriaceous basalt. The lava emanating from these 
centres poured into the valleys in streams from 100 to 200 feet thick, flowing 
for a distance of from 6 to 12 miles. Dispossessed of their old beds, the creeks 
and rivers had to wear for themselves fresh channels, either down the centre 
of the lava stream, or along one or both of its margins That the 
volcanic activity was prolonged for a vast space of time is proved by the 
extent of denudation which has taken place between the older flows of lava 
and the newer. The amount of this can be measured at the upper end of the 
Vegetable Creek Deep Lead, at Dose Valley The section at 
Griffiths and Vox’s shafts shows that a watercourse has cut through one or 
more flows of basalt, altogether to a depth of about 60 feet. Then succeeded 
another flow of basalt, which buried the second channel to a depth of 100 feet. 
. . . . Powerful streams must have flowed in places over the surface of 
the basalt, long after its consolidation, as evinced by the coarse Pliocene 
