Vol. 58. ] THE SUFFOLK CHALKY BOULDER-CLAY. 13k 
origin. I have seen similar grains in Lower Greensand material, and also in 
Middle Liassic marlstone.’ 
This again points to sources among Secondary rocks, and in a 
westerly direction. 
The residues all contain grains of silica, but the dark clays much 
fewer than the red and yellow; indeed, often extremely little. For 
instance, in the residues from Corton and League Hole the grey 
granules form the chief part, and in the small remainder chalk 
predominates. These two localities are on the coast-cliffs north of 
Lowestoft, looking out on to the North Sea, with its sandy bottom: 
under the clays lie sands which extend to the north for several 
miles—the so-called Mid-Glacial Sands. It is difficult to conceive 
how a material containing so little quartz could be produced or 
brought by any agent moving over the sea-bottom. If this be true 
for coast-cliffs, it must hold good of the other dark clays, on the 
landward side of these. ‘Therefore we must not look for the origin 
of these clays eastward, in the direction of the sea. 
While examining the clays of the Yorkshire coast, I have several 
times noticed in the cliffs included patches of coal-gravel. Micro- 
scopic coal [ have found in the samples from that.district universally. 
The Geological Survey Memoir on East Lincolnshire repeatedly 
mentions small pieces of coal as occurring there in the Boulder-Clay.’ 
It came into my mind to examine whether such coal-fragments 
could be detected in the East Anglian area. Accordingly I have 
scrutinized all the washed residues with an eye to this point. 
Coal is so unchangeable by weathering or decomposition, that one 
would expect the question to be readily settled. It is, however, not 
so easily disposed of. ‘here is little difficulty with such pieces as 
can be removed from the powder for separate examination; but 
black grains occur, too small for me to pick out. As in the residues 
are fragments of black chert, very dark limestones, black spines, 
enamel, or bone, black grains may belong to these. I have to rely 
upon eye-comparison with the coal-dust in similarly treated clay- 
residues from Tynemouth, Sunderland, and the Holderness clifts. 
My conclusions therefore may not be absolutely certain, still they 
agree fairly well together. 
In some of the samples there appear to be no black grains at all; 
in most, such as are there seem to me not to be coal. Only at 
Pakefield, and perhaps in the pits near Saxmundham, I incline to 
think that some may be present,—microscopic grains merely ; nc 
fragment large enough for me to isolate. Pakefield is on the coast , 
Saxmundham about 6 miles from the sea, on the edge of the clay- 
plateau. ‘This apparent absence of coal from the main dark-clay 
area, and also from Boston and Ely, contrasts not only with the 
presence of coal visible to the unaided eye in Kast Lincolnshire and in 
the Leicestershire clays, but also with the presence of what seems 
1 A. J. Jukes-Browne, Geol. Surv. Mem. 1887, pre 72, 87, 89, & 98. 
OMe 
