Conglomerates, and Mark of Devonshire. U7 
fewer than three of the great geological periods. Its basement is 
red sandstone overlaid with red marl, both belonging to the Tri- 
assic period, and each destitute of fossils ; on them reposes the 
Greensand crowded with organic remains of the Cretaceous era ; 
and this, in its turn, supports gravel rich with chalk flints, which 
was probably laid down in Quaternary times, and certainly after 
the valleys of south-eastern Devonshire had been formed, since it 
lines all the valley slopes and crowns the summits of all the hills 
bounding them, from the Teign eastward, at least to Dorsetshire. 
Standing on the High Peake and lookiug eastward, it is seen 
that its leading phenomena are repeated in every hill as far as the 
eye can reach ; everywhere the strongly contrasted colours indicate 
that the basement is of Triassic, and the higher levels of Greta 
ceous, age. The deep, yet in most cases gently-sloping, and there- 
fore wide, valleys testify that they were formed by the denudation 
of large masses of the formations represented by the hills ; the 
gravels show that this excavation was completed before their era, 
yea, they show that the valleys were deeper and wider in pre-gravel 
times than they are at present. They indicate a period in which 
they spread far and wide over the country, covering the hill tops 
and obliterating the valleys ; and, though apparently destitute of 
fossils, they contain lithodomized stones, and thereby suggest that 
they were laid down during a period when the country gradually 
sank many hundred feet below its present level, until the ocean 
prevailed over our hills; and that the valleys were partially re-exca- 
vated during a period of gradual and uniform upheaval. 
But to return to the base of the hill. The Triassic beds, which 
alone claim attention at present, consist of marl and sandstone. 
The former is the most prevalent, and possesses all the characters 
of the same substance west of Budleigh Salterton — the same 
tendency to break into angular fragments, the same greenish 
circular patches and discontinuous parallel bands, and the same 
frequency of small land-slips, owing to the presence of springs. 
Nevertheless the marl between Sidmouth and the High Peake is 
