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Survey Details for CRMRTGL308 - 2026-06-06

CRMRTGL308

Geological Landscape

Afon Cennen

Carmarthenshire

2008-12-30

  • Level 1: Lowland hills and valleys
  • Level 2: Lowland river and drainage systems
  • Level 3: Active lowland river-flood plain system

Monitoring

Q1 - Date of monitoring?

  • No Answer

Q1a - Monitoring undertaken by

  • No Answer

Q1b - Has this record been updated following monitoring work?

  • No Answer

Q1c - Change indicated by

  • No Answer

Q1d - What has changed?

  • No Answer

Q1e - Has the information ever been verified in the field?

  • No

Q2 - Does this area have a special or functional link with an adjacent area?

  • No

Description

Q3 - If Classification is "Other", specify here

  • Empty value

Q4 - What is the geographical and topographical character of this area?

  • Alluvial floodplain (Quaternary: Holocene) and channel of the Afon Cennen from its confluence with the Towy near Ffairfach to the Carreg Cennen Castle area. Highest part occupies narrow valley, gorge-like in places, and has a more upland stsyle (but not altitude). Flow is WSW to the Derwydd area where the system ia defelcted to the NW and then NE towards Ffairfach. Floodplain broader in these latter areas and the river is of lowland style.

Q4a - Where bedrock dominated, what is the dominant bedrock type?

  • No Answer

Q4b - Where bedrock dominated, what is the age that characterises the aspect area?

  • No Answer

Q4c - Where bedrock dominated, what is the major rock lithogy (-ies)?

  • No Answer

Q4d - Where drift dominated, what is the dominant drift deposit?

  • Glacial

Q4e - Where drift dominated, what is the major sediment that characterises the area?

  • Boulder clay/till

Q5 - What is the characteristic Level 3 component of the area?

  • Active lowland river-flood plain system

Q6 - Which of the following is a significant contributor to the geological character of the area?

  • Stratigraphic formation(s)
    • Minor 'Didymograptus Shales' ('Bifidus Beds'), Ffairfach 'Group' / Formation (= Drefach Group, part?) (including 'Ffairfach Grits', 'Pebbly Sands', 'Flags and Grits', 'Ashes and Lavas', 'Rhyolitic Conglomerate') [ORDOVICIAN, LLANVIRN: ABEREIDIAN-LLANDEILIAN].
  • Superficial deposits
    • Glacial clay dominates [QUATERNARY: PLEISTOCENE]. Fluvial deposits, mainly floodplain alluvium, and probaly low terrace deposits [QUATERNARY: HOLOCENE].
  • Active processes
    • Fluvial
  • Past processes
    • Glacial

Q7 - What additional subsidiary Level 3 components are notable?

  • No Answer

Q8 - What Level 4 components are notable in this area?

  • River channel (natural)
  • Flood plain

Q9 - What active geological and geomorphological processes are significant in this area?

  • Fluvial
  • Empty value

Q10 - Are there components of significant hydrological importance?

  • Yes
    • Fluvial

Q11 - Are there any pedological processes that are significant in the area or have had a landscape forming effect?

  • No

Q12 - Is there current mineral extraction?

  • No

Q13 - Has there been mineral extraction in the past?

  • Not known

Q14 - Are there SSSI/GCR sites here?

  • Yes
    • Ffair Fach Railway Cutting and River Section SSSI [Ffair Fach Railway Cutting and River Section (1) GCR site (SN628211): Ordovician, Arenig-Llanvirn. Ffair Fach Railway Cutting and River Section (2) GCR site (SN628211): Ordovician, Llandeilo] [minor part].

Q15 - Are there geological SINC, 2nd tier, or RIGS sites in the area?

  • No

Condition

Q16 - Value

  • High
    • Includes minor part of GCR / SSSI features of national / international importance.

Q17 - Condition

  • Good
    • Rural area with no significant development.

Q18 - Trend

  • Constant
    • Rural area with no significant development.

Recommendations

Q19 - Existing management

  • Generally Appropriate

Q20 - Existing management remarks:

  • Rural area with no significant development.

Q21 - Principal management recommendations

  • Ensure that no features or natural systems of geological or geomorphological significance in the area are lost or damaged (e.g. due to development or forestry). Ensure that SSSI features are maintained in favourable condition by implementation of management plan.

Q22 - Guideline

  • Long Term
    • Ensure that no features or natural systems of geological or geomorphological significance in the area are lost or damaged (e.g. due to development or forestry).
  • Long Term
    • Ensure that SSSI features are maintained in favourable condition by implementation of management plan.

Tolerance To Change

Q23 - Are there any significant threats to the current integrity and condition of the Earth Heritage features of the area?

  • Not known

Aspect Area Boundary

Q24 - To what level was this information site-surveyed?

  • Level 3

Q25 - At 1:10,000, how much of the Aspect Area boundary is precise?

  • Most
    • Aspect Area boundaries surveyed at 1:10,000 using aerial photographs, mapped at 1:25,000.

Q26 - What baseline information source was used for Aspect Area boundary mapping?

  • Other
    • 1:50,000 British Geological Survey maps, 1:10,000 aerial photographs (as stereo pairs), OS 1:25,000 Landranger topographical maps.

Q27 - If OS Data was used, what was the scale?

  • 1:25,000

Q28 - What is the justification for the Aspect Area boundaries?

  • Break of slope at edge river floodplain / terrace/ drift filled valley systems

Evaluation

Q29 - Evaluation Criteria: Research Value

  • High
    • Includes minor part of GCR / SSSI features of national / international importance.

Q29a - Evaluation Criteria: Educational Value

  • High
    • Includes minor part of GCR / SSSI features of national / international importance.

Q30 - Evaluation Criteria: Historical Value

  • High
    • Includes minor part of GCR / SSSI features of national / international importance.

Q31 - Evaluation Criteria: Rarity / Uniqueness

  • High
    • Includes minor part of GCR / SSSI features of national / international importance.

Q32 - Evaluation Criteria: Classic Example

  • High
    • Includes minor part of GCR / SSSI features of national / international importance.

Q33 - Evaluation Criteria: Overall Evaluation

  • High
    • Includes minor part of GCR / SSSI features of national / international importance.

Q34 - Justification of overall evaluation

  • Includes minor part of GCR / SSSI features of national / international importance.

Bibliography

Q35 - Sources and additional assessments

  • INSTITUTE OF GEOLOGICAL SCIENCES 1977, Sheet 230 (Drift), 1:50,000 Geological Series; ARCHER, A.A. 1968, Memoir of the Geological Survey of Great Britain (England and Wales), (Sheets 229 pt, 230, 246), HMSO. STRAHAN, A. et al. 1907, Memoirs of the Geological Survey (England and Wales), HMSO. ORDNANCE SURVEY 2002a, Explorer Map OL12 (1:25, 000). ORDNANCE SURVEY 2003a, Explorer Map 186 (1:25, 000). RUSHTON, A.W.A. et al. 1999, Geological Conservation Review Series 18, JNCC.

Assessment

Q36 - Additional Assessments

  • None

Q37 - Additional Comments

  • Additional Level 4 features include: Meander