WGCG Spring 2021 Newsletter - Flipbook - Page 19
WGCG
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Spring 2021 Newsletter
Napton Hill Quarry
SSSIID 1002121
Napton on the Hill is an outlier of the major escarpment of the Middle Lias in south-east Warwickshire. The
SSSI is an old brick-pit capped by the Marlstone Rock Bed consisting of a ferruginous, sandy, shell-detrital
limestone, which is oolitic in patches. The beds below the Marlstone Rock Bed comprise mostly siltstones
and silty mudstones with impersistent beds of ferruginous limestone and sandstone. The brick pit has
magnificent suites of Lower and Middle Lias fossils worthy of palaeontological and biostratigraphical
study. However, the Lower Lias is no longer exposed.
Napton Hill Quarry in its
working days – the
Marlstone Rock is the
dark bed at the top of
the face.
Photo credit:
Warwickshire County
Council collection
Napton Hill Quarry
(January 2021) showing
extent of vegetation growth
and talus masking the face.
The Marlstone Rock can be
seen at the top.
Photo credit:
Deborah Parke
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Cross Hands Quarry SSSSID 1001270
This disused quarry exposes carbonate sediments of Middle Jurassic age (170 million years ago). It has some
of the most extensive and most northerly exposures of the Clypeus Grit (Upper Inferior Oolite). This
comprises approximately 3.5 metres of pale cream to bluff-coloured, fossiliferous limestones with
interbedded, less-resistant marl units. Within the Clypeus Grit, bivalve molluscs and brachiopods are
particularly abundant. The overlying Hook Norton Limestone represents the basal units of the 'Great Oolite
Group' and comprises approximately 2.5 metres of fawn, oolitic limestone. The fauna is poorer than in the
Clypeus Grit; bivalves predominate, along with fragments of wood (ginko).
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