362 <A. R. Horwood—Upper Trias, Leicestershire. 
is greater in the Lower Keuper than in the Red Marls. On the whole 
there is, where the sandstones are fully developed, one-third sandstone 
to two-thirds marl. In the Red Marl the proportion, even including 
skerries and thin sandy beds, is hardly more than one-twelfth. This 
relative proportion of marls to sandstones is, taken in conjunction 
with their place in the full sequence, following pebble beds, the 
natural succession in aqueous deposits, especially those originated by 
a river and forming in due course a delta. : 
Not less clear, as seen by a study of the petrography, is the fact 
that, commencing with the Bunter, the deposits graduate upwards 
into finer and finer sediments right up to the Rheetics. It is true 
that there are interbedded coarser sands in the marls high up, but 
these are explained as abnormal in the lake phase, and they are as 
a whole most predominant between the pebble beds and the lower 
part of the Upper Red Marls, their proper position in a delta 
succession. 
In the Coal-measures laid down under delta conditions, there are 
rock courses or ancient river-beds in the lower part of the Middle 
Coal-measures. They do not appear higher up, and it is clear that 
the highest red beds, like the Red Marls, represented the lake phase. 
In the Trias we should not expect to find traces of the river-bed 
higher than the Lower Keuper, and though there is no strict analogy 
to be pointed out, yet in Bunter and Lower Keuper delta bedding 
and wedge-bedding and similar obscure types of deposition indicate 
that a river-bed might be sought if sections existed under Liverpool 
or in that direction, assuming one river came from the north-west. — 
The direction from which the sediments came may be to some 
extent proved by the occurrence of extraneous material for which 
a definite source can be adduced. Thus the occurrence of galena in 
Carboniferous Limestone nodules in the Lower Keuper at Shepshed, 
which is found in situ at Dimmingsdale to the north-west, furnishes 
one indication. Coal has been found also in the Upper Keuper 
Sandstone at Leicester, and it is reasonable to assume that this also 
was derived from the north-west, or the Ashby Coalfield. © 
The constant occurrence of current or delta bedding, noted in many 
instances in describing the stratigraphy, both in the Lower Keuper 
Sandstones and the Upper Keuper Sandstones, shows that, on the 
whole, they follow the direction of dip to the south-east (from north- 
west). When beds are uniformly bedded in this way it is usually 
held that, as in the Coal-measurtes, river agency produced the oblique 
laminations. This, again, points to the direction of the river and source 
of sediment. 
Again, the evidence of ripples shows that the period was marked by 
constant shallow-water conditions, and the presence of land in the 
vicinity, with intervals of depression between. ‘The ripples trend 
largely north-west and south-east in the Red Marl, varying mostly in 
the Lower Keuper, to the opposite direction, and in the latter the dip 
is also more variable. I consider the crest of the ripple was parallel 
to the direction of the flow, and do not think they were produced by 
a river at right angles from the south-west, but were formed by 
lateral ebb and flow. It has been suggested that in the variegated 
