DEPOSITS OP THE LEEN VALLEY. 
113 
volume of water borue down the valley must have been many times 
greater than it is now. Some of the irregularities of the bedding may 
be due to the melting of lumps of ice or snow, which may have got 
buried along with the sediment. However this may have been, the 
oblique lamination seemed to indicate the influx of water from the 
side of the valley, as well as an onward movement down the valley. 
Its pebbles were the same as occur in the Drift, from the destruction 
of which it was most likely derived. 
There was evidently a long interval of time between the formation 
of the Drift at the bottom of the valley and the accumulation of this 
torrential gravel, during which a considerable amount of gravelly 
material was probably carried away altogether, leaving those scattered 
patches and terraces of rusty brown gravel higher up the valley slopes. 
It was during this interval that the ice-cap that had previously 
shrouded the land melted away, and the climate became less severe. 
Once more the Leen appears to have begun to deepen its bed, and to 
form the “ valley within valley” which its later Post-glacial or “ recent ” 
deposits were found to occupy. The lowest stratum of these deposits 
consisted of rusty-coloured coarse gravel, containing thin seams of red 
sand derived from the wearing away of its rocky bed, and full of flakes 
and pebbles of red hematite, as at Radford. This gravel was overlaid 
by a bed of light gray sand, very evenly laminated, and maintaining a 
tolerably uniform thickness all round the cutting. Above this came a 
band of peat, full of the stems of young trees, twigs, and leaves, all 
more or less decayed ; while the roots of many of the trees descended 
into the underlying sand bed. The peat varied from one to three feet 
in thickness. Many of the tree stumps were vertical, or nearly so, just 
as they must have grown. On the west side of the cutting the stool of 
an oak, about twelve inches in diameter, gnarled, but black and quite 
decayed, was met with at the bottom of the peat. The peat passed up 
into about three feet of lead-gray silt and dark surface-loam. The 
materials that composed the brown gravel resembled those of the Drift, 
except that the latter contained no hematite. Nor does the red 
hematite occur in any other of the gravelly deposits that line the 
valley, so far as I have observed. One curious fact connected with 
these Post-glacial deposits remains to be noticed. Between the rusty 
coloured gravel and the solid rock on which it rested at Old Radford 
were two or three small patches of peat (shown in the sketch. Fig. 1)— 
apparently all that was left of a more extensive layer that once lined 
the sides of the rocky ravine which the Leen then occupied. At that 
time (1879) I could hardly believe these fragments of peat were in situ, 
and examined the spot carefully to see if they had not somehow fallen 
down from the overlying peat bed during the work of excavating. 
On making my usual visit to the cuttings at Basford one day in the 
spring of this year, however, I was met by one of the superintendents 
of the works with the startling announcement that they had come 
upon a mass of peat imbedded right down in the heart of the sandstone 
rock (i.e., the Lower Mottled), underlying the alluvium, and therefore. 
