Geological Sites | Leeds
| Bradford | Calderdale
| Kirklees | Wakefield
 STATUS:
Local Geological Site
OTHER DESIGNATIONS:
COUNTY: West Yorkshire
DISTRICT: Calderdale
OS GRID REF. SD 983 274 – 962 282
OS 1:50,000 Landranger 103 Blackburn and Burnley
OS 1:25,000 Explorer OL 21 South Pennines
BGS 1:50,000 Sheet 77 Huddersfield
FIRST DESIGNATED by West Yorkshire LGS Group in 2000
MOST RECENT SURVEY West Yorkshire Geology Trust in February 2009
DESIGNATION SHEET UPDATED August 2009
SITE DESCRIPTION:
Colden Clough is the finest example in Calderdale of a rejuvenated
river system. The
lower reaches form a steep, rocky clough, where the stream is eroding
deeply into the
bedrock, in response to the deepening of the Colden Valley at the end
of the Ice Age
approximately 10,000 years ago.
Jack Bridge marks the position of a knick point, where the steep clough
levels out to form
the original valley of Noah Dale. Here the stream has not been rejuvenated
and flows
through the broad valley at a gentle gradient.
The river has incised into
the alternating shales and sandstones of the Upper
Carboniferous Todmorden Grit, which is a coarse and massive sandstone.
McCabe
(reference below, p275) mentions that two giant cross-bedding sets
can be seen on both
sides of the valley at Colden Water and they can be followed for
300m. This represents a
very large fluvial channel eroded into a delta top.
HISTORICAL ASSOCIATIONS:
The Colden Valley is an important industrial archaeological site, because
of the history of
cotton mills during the industrial revolution.
EDUCATIONAL VALUE:
AESTHETIC CHARACTERISTICS:
Colden Clough is valued for its unique landscape and wildlife habitats.
There are
prominent exposures of Todmorden Grit above the clough.
ACCESS AND SAFETY:
By footpaths and tracks from Mytholm, Heptonstall and Jack Bridge
- Colden Clough lies
within an area of access land.
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