The document describes waterfalls located along the River Twiss and River Doe near Ingleton, North Yorkshire. It includes photos and questions about the geology and features of the waterfalls, such as the vegetation, relief, and erosion patterns visible. Differential erosion has created circular plunge pools below harder limestone bands. Over time, waterfalls will move upstream, leaving steep gorges as the erosion process continues.

1. Waterfalls
The River Twiss and Doe near
Ingleton, North Yorkshire

2. Describe the environment
• Vegetation
density
• Vegetation
type
• Relief
• = height
and shape
of the land
• Cross-
section

3. River Doe
• What does the
colour of the water
tell us about the
environment
upstream of this
fall?
• Clue - the rock
type is Limestone,
what is the soil

4. Features
• Can you identify
the features of
each image?
• And what is
happening here?

5. Differential
Erosion
• Less resistant rock is
eroded more easily
than adjacent harder
layers
• Can you identify the
bands of harder rock?

6. Top fall on the
River Doe
• What does this
image suggest
about the depth of
the plunge pool?
• Tomb stoning has
been banned at
Devils Bridge since
a death last year!

8. Above the River Doe the land emerges to improved moorland
- albeit enclosed. What altitude do you think it drops to the
river valley? Is there any evidence of glaciation?

9. Thornton Force on the River Twiss

10. Geology
• Was the rock
formed in layers?
Is it sedimentary?
• Is it blocky in its
structure?And
grey?
• Which rock do you
think it is? Think
back

11. The lower [older]
rock below
• The darker rock
below has been folded
and changed to form a
less resistant
metamorphic rock
• Any idea what rock
you think it is?
• With limestone above
and slate below the
water spray cuts back

12. • Harder limestone
on the top
• Less resistant slate
underneath
• Note the waterfall
is free-hanging
• Niagara Type
Rock Sequence

13. Plunge Pool
The plunge pool is
circular, deep and
gradually moving
upstream
Material is deposited,
gradually infilling the
pool

14. • Gradually the pool
becomes shallower and Downstream
the river bed returns to
a riffle.
• Note the bystander
ankle deep in the water.

15. • Some of the bigger
blocks which fall into
the plunge pool cannot
be removed as the
river loses all of its
energy here.
• Note the blocky
nature of this
carboniferous
limestone.
• How is the area being
used as a recreational
resource?

16. Evolution
• The waterfall
gradually moves
upstream leaving a
steep sided gorge
below it, often with
smaller falls
• The process continues

17. Credits
• Produced by Jacob K OLLIS Aged 8
• Photography Mark Ollis
• Head of Geography, St Bees School,
Cumbria
• The “Aberant Bee”

18. Additional Information for Teachers
• This power point was based upon a family walk from Ingleton, up beside the chip shop
returning via the normal footpath up and the car park. This was a sustainable
alternative to parking at a honey pot location and following the route, initially across
private land and paying to access public waterfalls. A payment may be necessary if you
continue down into Ingleton anticlockwise.
• Both rivers have conflicting names on OS maps and locally. Above Thornton Force the
river Twiss is called Kingsdale Beck OS GR 7077, but in the gorge SD6974, the Twiss.
The River Doe changes from Chapel Beck at 7376 to the Doe 2 km downstream. Both
rivers flow independently under the access bridges to the waterfall carpark before
joining before the old viaduct. Below this tributary the river is called the River Greta
[6571] and this is the river that is observed from the A65 outside of Ingleton at New
Bridge – an obvious metal construction. I am sure you can access all of these sites via
Get-a-map or aerially via Multi map. To further confuse things the climbing Guide
‘Yorkshire Limestone’ refers to the crag dividing Kingsdale from Chapel le Dale as
Twistleton rather than Twisleton [7276] so it could become the River Twist!
• For information on rock types and the general orientation I used Yorkshire Dales:
Limestone Country by Tony WALTHAM this is a Constable guide that was re-published
in 1987 but it is excellent if you like limestone. He draws attention to the excellent
terminal moraine above Thornton force and the ease of access over public land from
above – this is obvious on a 1:25 000 map with Open Access information highlighted so
don’t be perturbed by the need to pay. He includes three additional useful facts: That
the slate was overun by the sea 330 million years ago, that the fall is 14m high and
that it has retreated 60m in 14,000 years since it overtopped the terminal moraine.
• The gorge on the early slides is Baxenghyll above the Snow water falls, the upper fall
– with jumpers – the Beezley falls MO mark.ollis@st-bees-school.co.uk