Folds, faults and rock movements

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 structural and metamorphic geology blocks relate to the effects of mountain-building activity. The GCR blocks reflect the variation across Britain in the deformation processes during three major mountain building episodes (Caledonian, Variscan and Alpine). These blocks include geological features such as folds and faults and other effects resulting from compressional and tensional forces acting within the crust of the Earth.

Four blocks relate to Precambrian rocks in Scotland: Torridonian, Moine, Lewisian and Dalradian. Three of these, Moine, Lewisian and Dalradian, have been deformed and metamorphosed during mountain building.

Summary statistics

	A/SSSI	Total
Favourable condition	94%	94%
Main monitoring coverage	E, S
Reported assessments	139	139
Completeness of assessments	approx.40%
Distribution of features		UK

Number of assessments reported by country and site type

Country	SSSI/ASSI
England	45
Scotland	93
Wales	0
Northern Ireland	1
United Kingdom	139

SSSI features

List of SSSI and ASSI interest features in this reporting category

Interest feature name
Formal name	Informal name	No. of assessments reported
Alpine structures of southern England	Alpine structures of southern England	10
Caledonian structures	Caledonian structures	9
Caledonian structures of the Lake District	Caledonian structures of the Lake District	9
Dalradian	Dalradian	27
Lewisian	Lewisian	1
Moine	Moine	52
Torridonian	Torridonian	5
Variscan structures of south Wales and the Mendips	Variscan structures of south Wales and the Mendips	1
Variscan structures of south-west England	Variscan structures of south-west England	25

This list has not been fully standardised at a UK level yet. It is intended to show the principal constituent "feature types" for this reporting category.

Maps - distribution

UK distibution of reported interest features

Distribution of reported interest features.

Map showing the locations of the 10km squares in which at least one condition assessment has been reported. It does not show features that have not yet been assessed.

Maps - SSSI

Current condition of SSSI/ASSI features
Distribution of SSSI/ASSI features showing assessments of favourability (where unfavourable-recovering is counted as unfavourable).

Condition of SSSI/ASSI features, with those currently reported as unfavourable-recovering shown as favourable
The implication of the unfavourable-recovering condition assessments is that at some point in the future these features should become favourable. This map shows the effect of that recovery by counting the favourable and unfavourable-recovering assessments together.

IMPORTANT NOTE: we do not have information on the timescale of the predicted recovery, which may be influenced by many past, natural and human related factors. A sustained sympathetic management regime is more likely to result in favourable condition being attained.

Key: Proportion of assessed features on 10km squares that are favourable:

SSSI map legend - Proportion of assessed features on 10km squares that are favourable

Details of how these maps were produced

Condition summary

This lists the 10 different condition assessments and presents a bar chart showing the number of features within the SSSI series. Note that we are unable to estimate the total number of SSSI/ASSI features because we do not have an overall list of notified interest features for these designations.

NB favourable unclassified and unfavourable unclassified have been used in this first six year cycle to get around difficulties in identifying trends in condition as common standards monitoring is implemented. It is expected that these categories will not be used for subsequent assessments of a feature.

Condition assessment - SSSI features

The number and proportion of assessments for SSSI/ASSI interest features falling into each of the condition categories. Note that the �unfavourable� category includes all reports of unfavourable condition except �unfavourable recovering� which is shown as a separate segment.

Adverse activities

The number of interest features where an activity has been reported as being implicated in the "unfavourable" condition of a feature. More than one adverse activity may be reported for each feature.

Management measures

For each "measure" the chart shows the number of interest features where that measure has been taken on a site to improve or maintain the condition of an interest feature. More than one measure may be reported for each feature assessed.

Interpretation

About 40% of sites with folds, faults and rock movements are accounted for in the report, of which 94% are reported in favourable condition. This is above the average for geological features and well above the average for all features combined.

This is an expected result, because most features are robust (hard) rocks and less likely to be affected by activities that are damaging to soft rock or dynamic landscapes.