-
8/9/2019 Underground Waters Land Forms
1/23
Limestone Features
Miss James
Higher
-
8/9/2019 Underground Waters Land Forms
2/23
-
8/9/2019 Underground Waters Land Forms
3/23
Limestone
Blue area
arboniferous
Limestone
!or"shire
#ales
-
8/9/2019 Underground Waters Land Forms
4/23
Limestone consists mainly of calcium carbonate$ %here are
several different types of limestone including hal",
Jurassic
and arboniferous$
& %he arboniferous Limestone can be attac"ed by
the'eathering process of carbonation$ %hin" aboutchemical
'eathering$ %his 'eathering contains a very
distinctive type of landscape, 'ith both surface andunderground
features$ %he most distinct landscape ofthis "ind is found in
theYorkshire Dales$ Here thelimestone forms upland areas, capped by
impermeableroc"s above, and separated by flat(floored and
steep(sided glaciated valley)s called dales$ *laciers coveredthis
area and as 'ell as sculpting the valley)s, alsoremoved loose roc"
and soil to expose the limestone'hich 'as then more open to
chemical 'eathering$
-
8/9/2019 Underground Waters Land Forms
5/23
a+ - H.+ - +. / aH+.
alcium carbonate - 2ater - arbondioxide / alcium bicarbonate
3mpressive4
-
8/9/2019 Underground Waters Land Forms
6/23
!or"shire #ales
-
8/9/2019 Underground Waters Land Forms
7/23
Limestone& 5urface and rain 'ater do not flo' far on
exposed limestone, but infiltrate rapidlyinto the roc" and soil$
2here a 6oint or
intersection of 6oints has been greatly
'eathered or dissolved 'ater can passdo'n through the
limestone
arboniferous limestone is a sedimentary roc" formed in the
!or"shire #alesaround 00 million years ago$ %hese roc"s 'ere laid
do'n on the sea bed and
made up of layers of ancient corals and s"eletons of sea
creatures living in the
shallo' seas at that time$
-
8/9/2019 Underground Waters Land Forms
8/23
!or"shire
#ales
-
8/9/2019 Underground Waters Land Forms
9/23
Joints and Bedding 7lanes
%his is hard grey roc", laid do'n in layers on
the sea bed$ 3t occurs in massive bloc"s
bordered by hori8ontal bedding planes
and vertical joints$ %hese bedding planes
and 6oints ma"e the roc" permeable i$e$
'ater can pass through it$
-
8/9/2019 Underground Waters Land Forms
10/23
lints and *ri"es
-
8/9/2019 Underground Waters Land Forms
11/23
lints and *ri"es
& %hese are flat areas of exposed limestone$
5urface soil 'as probably removed by the
glaciers$ arbonation 'eathering has
enlarged 6oints to give 'ide gaps called
grikes. %he stones left are called clints$
5ome are 0$9m 'ide and .m deep$
http:;;'''$bbc$co$u";scotland;education;int;geog;limestone;surface;their
-
8/9/2019 Underground Waters Land Forms
12/23
5in";5'allo' holes
-
8/9/2019 Underground Waters Land Forms
13/23
5'allo' holes
& 3n the !or"shire #ales, streams flo' onimpermeable roc" on
higher hillsides$2hen the streams reach the limestone,
they usually only flo' for a short distancebefore disappearing
underground at as'allo' hole sin" hole$ %hese developat the
intersection of ma6or 6oints 'hichhave been 'idened by solution$
%his canbe seen at *aping *hyllin the !or"shire#ales$
-
8/9/2019 Underground Waters Land Forms
14/23
*aping *hyll
-
8/9/2019 Underground Waters Land Forms
15/23
+utcrops
-
8/9/2019 Underground Waters Land Forms
16/23
5talagmites, stalactites = 7illars
-
8/9/2019 Underground Waters Land Forms
17/23
-
8/9/2019 Underground Waters Land Forms
18/23
5talagmites, stalactites = 7illars
*round'ater may become saturated 'ith calcium
bicarbonate in solution$ 2ater continually drips
from cave ceilings$ 5ome 'ater evaporates to
leave a thin film of calcium carbonate lime$+vertime a narro'
stalactite may gro' do'n
from the roof of the cave$ %he drip of 'ater then
drops to the cave floor and evaporates from
there 'hich ma"es a stalagmite$ 3f these 6oin apillar is formed$
3n !or"shire caves stalactites
gro' at around >$9mm per year$
-
8/9/2019 Underground Waters Land Forms
19/23
*orges
-
8/9/2019 Underground Waters Land Forms
20/23
arboniferous limestone areas often havenear vertical roc" cliffs
along the sides of
valley)s$ %hese cliffs are "no'n locally asscars$ %hey are
susceptible to frostshattering physical 'eathering onexposed 6oints
and may have screeat
their base$ ?xtremely steep sided valley)sare called gorges$ @re
formed by cavescollapsing$
-
8/9/2019 Underground Waters Land Forms
21/23
aves
-
8/9/2019 Underground Waters Land Forms
22/23
aves;*orges
& #uring the melt'ater phase of the last ice
age, underground streams eroded vast
caverns as huge volumes of 'atertravelled through the
limestone$
5ometimes the roofs of these caverns can
collapse exposing the Aunderground
streamA in a very steep sided gorge$
-
8/9/2019 Underground Waters Land Forms
23/23
