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B e r k s h i r e :.

["b e l l y ' s

and the G a u lt are now seen to be so closely allied as to
C h a lk w a s fo rm e rly m o re u sed fo r b u ild in g th an a t p re s e n t’
constitute really b ut one formation, to which the name of
an d w h en c a r e fu lly selected is w e ll su ite d fo r in sid e w o rk,
bBLBORNiAN has been given.
(4) The W h i u C h n lT T h ,c
*.1 u * ,
being very easy to carve ; examples m ay be seen in Sonning
rock in F no
V
perhaps the best known Town and in Tilehurst churches. The chalk-rock affords a
it constitutes poor road-m etal.
Flints furnish an alm ost everlasting
:shire. On the m*»t.«ri«i
. 41__ 1___ 1____
, ...
§
5 across from Hungerford to
ince of 12 miles. The strike,
iere nearly east and west
or direction of the Chalk, is here
irest and the
of g t s s T n i Z ^ 2 S
“ P f° r
”
fnam es. The dip
din is
i« to
in the
t.Ko south-east
continues so to the Thames.
at a very sm all angle, from one to three degrees only. I n '
T e r t ia r y P e r io d : T h e E o cen e
S y s t e m . — A great
the south the Chalk dips under the T ertiary beds of the break in tfie succession of the rocks occurs at the top of the
valley of the Rennet, and rises up furth er south at a sharp W hite Chalk. In the strata now to be described, which
angle along a line from Inkpen to Kingsclere (in H am p- rest directly upon the C halk, we find the fossil remains of
s h ire ), at Inkpen Beacon the W hite Chalk attains an ^mmals altogether different to those w hich occur as fossils
elevation of 1,011 feet, the highest point reached by this in
Chalk, and we believe that there was a great interval
form ation in the south of England. The total thickness in
tifne between the deposition of the two sets of strata,
Berkshire of this great mass of white soft limestone is pro- during which either (1) no deposit was here formed, the
bably over 700 feet, but some of the upper beds are want- country having been raised above the sea-level and become
m g, having been eroded before the deposition of the Eocene a *and surface, or (2) deposits were formed which were
strata ; the Chalk was em inently a deep-sea deposit, for afterwards washed aw ay— denuded off— before the rocks of
when we examine it m icroscopically we find it to consist in
large p art of the tin y cham bered shells of foraminifera, !
a T o u g h fe rru g in o u s
being very sim ilar in composition, in fact, to the g r e y ish -1
b ro w n c la y . A t a b o u t
w hite ooze which numerous soundings have proved*to form
16 in ch e s fro m th e
b o tto m th e re are o c­
th e floor of the North A tlantic Ocean at th e present time.
casio n a l fla tten e d con ­
In the great mass of the W hite Chalk three main sub­
c r e tio n a r y n o d u les o f
divisions are easily recognised— Lower, Middle, and Upper
c la y iro n-stone, a b o u t
— and each of these can be furth er sub-divided into Zones
th re e in ch es th ic k , uu(for details of which see the a itic le in this volum e upon the
d er a la y e r o f scatte red
flin t pebb les (6) w h ic h
G eology of B ucks), which* can, indeed, be traced and
are for th e m o st p a rt
recognised righ t across England, wherever the Chalk is
1 s m a ll an d w h ite .
exposed.
c F erru g in o u s brow n
(a.) 7 he .Low er Chalk (total thickness, 215 feet) has
s a n d y c la y o r c la y e y
m arly beds at the base about 80 feet thick ; above these
sand a b o u t fo u r fe e t.
d B la c k c l a y ; v e r y
come layers of grey to w hite chalk 135 feet thick, including
bard and h om ogene­
a hard band called the Totternhoe Stone.
This lower
o us, an d s p litt in g u p
division m aj’ be seen in the G reat Western railway cuttin g
w h en d ry v ery uneven­
at \\ allingford Road station.
l y w ith a s o r t o f con (6.) The M iddle Chal/c (total thickness, 170 feet). Above
ch o id al fra c tu re , a b o u t
th re e fe et.
the lower chalk, we get about 170 feet of chalk w ith few or
no flints, but containing m arly partings which indicate the
-73 C e A. lin e o f flin t peblines of bedding.
o

bles.

A t th e o u tc ro p

(c.) The Upper Chalk (total thickness 330 feet), is
=■ £ a I thiS be(1 forms a C(ir*tin u o n s b a n d o f c la y
characterized by the presence of flints, which occur most j
-g | I iro n -ston e, fo u r o r liv e
frequently in sm all irregular lumps or nodules, but aiso in
f m ri ' ,n ch es
t h :c k ,
w ith
flat tabular sheets.
The origin of flints is still a vexed
pq ( s m a ll em bedded flin ts.
question : m any appear to have been form ed by the deposit
f f G reenish
lo a m y
of siliceous m atter on and around organic bodies, such as
to # j c la y
p a ssin g
d ow nsponges ; the flat tabular masses of flint would seem to have
- ;§ J w a rd s in to m o re debeen deposited along the bedding-planes probably after the
:
S f l 1 cid ed solid c la y a t the
consolidation of the rock. Such lines of flint m ay be seen
P3
j d ep th o f a b o u t th re e
in the sides of the railw ay cuttin g near PangDourn, and in
( fe e t.
the chalk-pits at Courage, north ox N ewbury, and a t CookJ u n c tio n o f L o n d on C la y an d W o o lw ic h a n d R e a d in g B ed s a t
ham Dean. Fossils are of frequent occurrence both in the
flint and the chalk ; sea-urchins or Echinoderrns belonging K i n t b u r y B r ic k -y a r d , n o rth o f P e b b le H ill.
to such genera as Holaster, M arsupites, and Min-aster, which we now have to speak were laid down as sediment
abound, w ith sponges, belemnites, and such shells as in seas, lakes or rivers ; perhaps both things happened.
Terebratula, Inoceramus, &c.
The base of the Upper
I . — L o w e r E o c e n e F o r m a t i o n , — ( 1 ) The Reading B eds
Chalk is formed by a hard cream -coloured band—
the Chalk Rock— some 8 or 10 feet thick, which from its in Berkshire rest im m ediately upon the Chalk, and were
superior hardness usually form s the top of the chief chalk form erly known as the “ Plastic C la y ; ” they consist of
escarpm ent. Thus we can trace it all along the northern alternations of clays and sands of m any colours, w ith rolled
Fossils are few, Ostrea bellovacina, which
brow of Ilsley Common and Childrey W arren ; the Ridge flint-pebbles.
W a y runs along th e edge, and sections are exposed at m uch resembles the oyster of the present day, being the
Commencing at Pros­
Cuckham sley Knob, &c. Th e main mass of the Chalk passes only one found in any num ber.
in Berkshire as far east as Rem enham ,W 'argraveand Maiden­ perous Wood, about two miles south of Hungerford, w e can
head, but W indsor Castle is built on an inlying boss, trace these Reading Beds aiong the south of the River
probably elevated by some local disturbance ; the rock is Rennet to two miles east of N ew bury ; on the opposite or
visible in the ice-house 111 the Castle grounds. Beds of northern side of the river they continue nearly to Theale ;
phosphatic ch ilk occur at W interbourne and at Boxford. then, after a gap formed by the connection of the Pang
They probably belong to the Marsupites-zone, and m ay be with the Rennet, we And the same clays, sands &c.
the highest of the Chalk strata (in order of succession)" ex­ spreading out east and west of Reading. Here they are
largely worked at K atesgrove, Coley Hill &c. The plastic
posed in Berkshire.
The scenery of the Chalk Downs is very m arked and dis­ clays are made into tiles, drain pipes, &c. ; the sands are
tinctive. The beautifully smooth swelling bill-curves are mixed w ith the clays in brick-m aking, or when w hite and
Thence the outcrop
covered w ith a short dense herbage which affords good clean are used in glass works.
pasturage for sheep and capital galloping grounds for continues about half a mile wide through Sonning and the
horses.
The higher p art of the chalk area is, however, two W altham s towards Windsor. There are numerous out­
often covered with clayey deposits, as south of Ilsley, and liers of the Reading Beds on the chalk hills north of the
then form s a soil on which the beech grows w e l l; b ut as a Lam bourn and the Pang, as at Beedon Hill, Basildon, and
ru le the wide open nature of the country is always dis­ Farnborough Copse. The junction w ith the Chalk below
cernible. The valleys are often waterless, the rain being is often m arked by swallow-holes, which are caverns or
•oon absorbed by the porous soil. W hite Horse Hili rises funnel-shaped pipes, into which the water, running down
893 feet above the level of the sea. Econom ically regarded, the slope of the T ertiary beds, enters and disappears.
chalk is valuable as a dressing for clay lands ; m uch is also
(2) The Lorulon Clay.— W here the junction of the London
dug to burn into lim e, and it form s an ingredient of Port­ C lay above with the Reading Beds below is exposed we see a
land cement. W hiting is solely m ade from chalk, K in tbury “ basement bed ” of blackish flint pebbles which are traversed
being the seat of m anufacture. The soft upper chalk is b y cracks, so th a t they fall to pieces on receiving even a gentle