Geological Sites | Leeds
| Bradford | Calderdale
| Kirklees | Wakefield
 STATUS:
Local Geological Site
OTHER DESIGNATIONS:
COUNTY: West Yorkshire
DISTRICT: Calderdale
OS GRID REF. SD 892 260 (Green Clough) to 903 266 (Whitaker Naze)
OS 1:50,000 Landranger 103 Blackburn and Burnley
OS 1:25,000 Explorer OL 21 South Pennines
BGS 1:50,000 Sheet 76 Rochdale
FIRST DESIGNATED by West Yorkshire LGS Group in 1996
MOST RECENT SURVEY West Yorkshire Geology Trust in February 2009
DESIGNATION SHEET UPDATED August 2009
SITE DESCRIPTION:
The rocks are Upper Carboniferous Namurian (Millstone Grit) and Westphalian
(Coal
Measures) sandstones, siltstones and shales, with some coal seams. This
sequence
coarsens upwards because of delta advance into a deep water basin, so
alternating beds
form several cyclothems. Green’s Clough cuts through the sequence
and exposes at least
4 sandstone layers in the stream bed and on the sides of the valley,
with intervening
mudstones and coals.
Cliviger Gorge runs along major faults, which form
weaknesses for subsequent
weathering and erosion to take place. It is an important geomorphological
feature, a
remarkable example of a glacially over-deepened valley formed by escaping
melt water
at the end of the last glacial period. The deepening of the main valley
caused tributary
streams to form hanging valleys, where the underlying strata are exposed
in steep sided
cloughs, such as Green’s Clough. Cliviger Gorge, with its precipitous
slopes, is prone to
landslips and rotational slides.
HISTORICAL ASSOCIATIONS:
There is a mine entrance at the SW end of the LGS, which produces some
acid mine
water.
There are many other features of interest in Cliviger Gorge. Evidence
of coal and lead
mining can be seen near Thieveley Scout. Riddle Scout is the site of
an 18th century
iron stone mine. There are many packhorse routes in the district which
enabled lead and
iron ore to be transported to Yorkshire for smelting.
EDUCATIONAL VALUE:
The Cliviger Valley contains many features of educational interest including
landforms,
major faulting, mineralisation, marine bands and exposures of Coal Measure
cyclothems.
AESTHETIC CHARACTERISTICS:
The dramatic landscape of the Cliviger Gorge can be viewed from its
extensive network
of footpaths.
ACCESS AND SAFETY:
Cars can be parked at Portsmouth off the main road, adjacent to the post
office. Green’s
Clough may be reached by the footpath leading through Chatham Hill Plantation
and can
be followed up the clough to the waterfall at the top which marks the
end of the LGS. It
has excellent views down into the clough and across Cliviger Gorge. Permission
would
need to be gained for access to the stream bed to examine the rocks in
detail.
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