and Ebbor Gorge are two geological gems nestling under the southern
flank of the Mendip Hills. The Ebbor Gorge National Nature Reserve
is a delightful wooded limestone gorge with way-marked trails and
great views while Wookey Hole is a show cave and paper mill.
Wookey Hole, the source of the River Axe, was once considered one
of the wonders of Britain. The cave, now open to the public, was
formed by the underground River Axe and is slightly unusual in that
it is formed not in Carboniferous Limestone but in Triassic Dolomitic
Cross-section from Swildon's Hole to Wookey Hole (click to enlarge
Aerial view of the Wookey area (click to enlarge view).
The River Axe can be seen flowing through the cave, and it resurges
at the head of the ravine near the show-cave exit. It has been followed
upstream by cave divers through several deep water-filled sumps to
the present limit of exploration at a depth of 90 m. The river drains
much of central Mendip, including most of the caves in the Priddy
area. Both Wookey Hole and several small caves in the ravine outside
have yielded important archaeological finds, including the bones
of the 'Witch of Wookey' (on show in the Wells and Mendip Museum)
and a Romano-British cemetery.
Ebbor Gorge is a National Nature Reserve with both geological and
wildlife importance. Here a slice of the Burrington Oolite
has been thrust up over the younger Quartzitic Sandstone and the
Coal Measures along the Ebbor Thrust. The gorge itself is incised
into the Clifton Down Limestone. This spectacular ravine was formed
by summer meltwater run-off during cold phases in the Pleistocene,
when underground drainage was prevented by permafrost. The narrowest
part of the gorge (The Narrows) forms a prominent 'knick point'.
This former waterfall is a consequence of valley rejuvenation during
the Pleistocene cold periods.
||The steep rocky limestone
slopes are cloaked in ancient ash woodland with many ancient woodland
species, while the rocky crags, cliffs and screes are home to many
ferns, mosses, liverworts, lichens and fungi. Butterflies are abundant
and many rare species can be found.
|Quarrying and mining
Iron, lead, limestone and coal were all once mined in the Wookey
and Ebbor area. Iron ore was mined in the 1890s at Higher Pitts
Farm. The ore was associated with a unique assemblage of rare secondary
lead, copper and manganese minerals. These minerals, Mendipite,
Chloroxiphite and Diaboleite are rare or unknown outside the Mendip
area. Lead was mined from rakes in the limestone between Pen Hill
and North Hill. A thin belt of Coal Measures strata occurs in Primrose
valley, at the foot of Ebbor Gorge.
||Coal was mined here from
a shaft 36 m deep in 1835, but the seams were very thin and only
a small amount of coal was mined. The most important commodity was
limestone. The Burrington Oolite was quarried from two sites on Milton
Hill, now both disused, for aggregate and lime. Quarrying in the
larger quarry in 1935 intercepted a vertical fissure which contained
remains of hippopotamus and straight-tusked elephant. These date
from the Ipswichian interglacial, about 120 000 years ago. The remains
are in the Wells and Mendip Museum.