Context
Geological Conservation Review (GCR) sites are selected for,
and grouped according to, GCR blocks, which are site-selection
categories for nationally important Earth science sites.
There are around 100 'blocks' and about 3,000 GCR sites in
Britain. Each 'block' represents a particular geological age
or Earth science theme, such as Marine Permian Stratigraphy,
Jurassic–Cretaceous Reptilia, Caledonian Igneous Rocks and
Quaternary of Scotland.
The mineral blocks represent scientifically-important,
mineral-bearing rock bodies, produced as the result of igneous,
metamorphic or sedimentary processes, including those that:
- have metal, or metal-ore-bearing rock bodies (e.g. gold, tin,
lead, copper, zinc and iron lodes);
- provide evidence for the geological development of British
mineral-bearing rocks, and co-incidentally have led to its mining
heritage;
- provide materials such as china clay, barite, gypsum, and
rare crystalline materials, such as Blue John, zeolites or
garnet.
All of these provide evidence for the geological
development of the United Kingdom.