Clay-balls, etc., from Banter Sandstone, Notts. bi 
Marls would at least suggest a similar source of origin for the 
two, whatever that source may be. 
When the clay-balls occur in situ it is often seen that a 
zone of white sand, from one-eighth to a quarter of an inch 
in thickness, surrounds the ball, while the general mass of 
sand is its normal yellowish-cream colour. As has been already 
noticed, the balls themselves are also dark red, with a greenish- 
grey centre. It would therefore seem that a process of leaching 
has been taking place in the clay throughout the ages, whereby 
the iron in the clay has been oxidised and brought to the outer 
rim of the clay-ball in a similar manner to that in which the 
“ ironstone-boxes ’ have been formed in the Northampton 
sands and other ironstones. 
In a similar manner the zone of white sand has been formed 
by the small quantity of iron which there surrounded the sand- 
grains, leaching out, or by being subject to molecular attraction 
by the zone of rich oxide in the clay. 
The leaching of the iron is probably subsequent to any 
movement in the clay, otherwise the remarkably clear and 
uniform line dividing the red and grey coloured marls would 
have been disturbed. 
Notwithstanding this clear line between the two colours, 
however, there are features in the clay which do indicate 
pressure and movement. 
In certain parts of the pit there are groups of small masses of 
clay which have been squeezed into flat lenticular slabs, and 
these are generally inclined in a kind of false-bedding plane. 
This may be due to creep in the rocks, or it may be due to more 
violent slip soon after the clay fragments were buried. But the 
most important movements are indicated in the clay-balls 
themselves. 
Careful examination of the balls shows that some few of 
the pebbles are totally embedded within the clay. The great 
pressure brought to bear on the clay after being buried in 
the sand has so crushed and moved it that some of the studded 
pebbles have been forced quite into the body of the marl. 
As far as I have been able to ascertain, none of the modern 
clay-balls contains beach pebbles within the mass,* but only 
on the surface. Also, in broken Bunter specimens we find 
slickensided, streaky pieces of clay dividing the pebbles, 
indicating that the clay has been squeezed into its present 
position among the pebbles by considerable pressure ; some- 
thing like a ball of putty would be forced through the fingers 
when pressed in the hands. 
Having noticed that the clay has moved thus within itself, 
we may next examine the included pebbles more closely. We 
* Excepting, of course, such as were originally in the boulder-clay, when 
these clay-balls are composed of that material. 
1914 Mar. 1. 
