UPLAND

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These slide-shows are all on the Prepwork folder
if you wish to copy any notes from them we will
not be stopping in class for you to do this
UPLAND LIMESTONE SCENERY
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INTRODUCTION This unit is about Carboniferous
Limestone Scenery its creation and the processes
that sculpt its distinctive features.
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It is called Carboniferous after the geological
time when it was first made.
It is an alkaline rock, made from granules of a
mineral salt called Calcium.
As a result of its chemistry, it can be dissolved
by acids in the environment, like plant
secretions or acid rain .
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1.These limestones were formed from the
fossilised remains of countless marine plants and
animals, such as corals, which lived during the
Carboniferous period, 345 - 280 million years ago.
2.These former sea beds were moved from the
Equator due to continental drift and forced above
sea level 280 - 230 million years ago.
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Britain during the Carboniferous? Here, on the
Great Barrier Reef off the Australian coast, is
the worlds biggest expanse of coral reef-
tomorrows limestone!
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There are several types of limestone in Britain -
this presentation will concentrate on
Carboniferous Limestone and look at the Yorkshire
Dales in particular.
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This type of landscape is more correctly known as
Glacio Karst - glacio because it has been
glaciated, and karst after an area in Slovenia,
which gives its name to this kind of landscape.
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In the Core textbook, read pages 120/1.
The text mentions five ways that glaciation
contributed to karst features. Describe and
explain them in your jotter.
The answers are on the next slide. Did you get
them all?
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• Stripping topsoil to expose pavement to erosion.
• Eroding away all the limestone in U-shaped
  valleys.
• Plucking and abrading valley sides into scars.
• Erosion of valleys on the surface during
  glaciation, features that are now dry valleys.
• Enlarging passages with glacial meltwater.

The creation of screes by frost-shattering, and
leaving erratics on the surface are not
limestone- only features! They occur with other
rock types.
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This is a glacial erratic come to rest in a
limestone area. The limestone has been eroded by
about half a metre since the end of the Ice Age-
how do we know?
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Limestone - Chemical weathering

• Limestone Calcium Carbonate (alkaline)
• Rainwater Carbonic Acid
• Carbonic Acid dissolves alkaline Calcium
  Carbonate
• This is called CARBONATION, a type of solution
  weathering.

Learn this at home!
There is no need to know chemical formulae, but
if you want to quote them, get them right!
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Carbonation / solution weathering also attacks
buildings made from limestone
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Limestone commonly comes in the form of a block
(B) called a Limestone Plateau. It is usually
sandwiched between two other rock types, here A
and C.
A
B
C
A CAP ROCK (IMPERMEABLE) eg. grit or basalt B
LIMESTONE ( PERMEABLE) C BASE ROCK (
IMPERMEABLE) eg. clay
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Horizontal bedding planes
Vertical joints
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Limestone is a permeable rock i.e. it allows
water to pass through its joints and bedding
planes. It is well jointed, full of horizontal
and vertical cracks.