| and Gravels near Newmarket. 165 
(3) Cemetery Pit, Exning. 
A large pit adjoining the cemetery at Exning now shows a 
good exposure of sands and gravels, apparently lying in a pocket 
in the Chalk. It is possible that sands and gravels of two different 
ages are here seen in juxtaposition, since a good deal of variation 
is to be observed in different parts of the pit. The eastern end is 
excavated in brown, highly ferruginous, sand with wisps of chalky 
clay and many blue flints. The north wall of the same pit 
consists of a lighter coloured sand, with much more Chalk and at 
the top the usual pipes filled with brown loamy material. All 
over the pit large flints are numerous, but judging from a careful 
examination of the piles of stones riddled out from the gravel, 
pebbles of distant origin are very rare; only a few blocks of sand- 
stone were seen, ranging up to 6 inches in diameter: no pebbles 
of igneous rocks could be found. 
Since some doubt exists as to the identity of the sands seen 
in various parts of the pit, samples were collected from different 
points and treated separately by the usual methods. 
(a) Eastern side of pit. This is a pale brown, clean, bright 
sand, of rather fine grain, with few stones: when washed it was 
found to be remarkably free from mud. The heavy portion was 
partially concentrated by panning, and being obviously ferruginous 
it was at once treated with acid, yielding a remarkably white 
sand with much glauconite. A fairly abundant heavy residue 
sank in bromoform. 
This residue consists of rather small grains which are as a 
rule distinctly rounded: the chief minerals present are iron 
oxides, brown tourmaline, abundant zircons, rutile, epidote, stauro- 
lite, hornblende in rounded grains and ragged fragments, together 
with kyanite and garnet, the last-named mineral being fairly 
abundant and in grains distinctly larger than the rest, suggesting 
a somewhat different origin. The zircons are notably abundant 
and more rounded than in samples from the neighbourhood of 
Cambridge. 
(6) Northern side of pit. This specimen consists of a rather 
light coloured fine grained quartz sand with fairly abundant dark 
grains and many very small chips of flint. A small sample when 
tested with acid gave a strong effervescence. The heavy consti- 
tuents were partially concentrated by panning and then separated 
in bromoform without previous treatment with acid. Grains of 
iron oxide were found to be so abundant as to necessitate treat- 
“ment with acid and a second separation in bromoform. This 
_ process brought to light a considerable amount of green glauconite 
and some pale brown grains of doubtful character. The heavy 
residue after the second separation was abundant and consisted of 
unusually small grains. Its general mineral composition also was 
