Geology and Soils
The National Park has a unique and visible geological character that is a fundamental part of its outstanding landscape and scenery which has been formed and re-shaped by complex processes such as plate tectonics, glaciations, weathering and erosion. Snowdonia has played an important role in the development of earth sciences, with many notable geologists visiting to undertake fieldwork. It contains a wealth of nationally and locally important geological and geomorphological features, and has a wide-range of soil types that are influenced by the underlying geology and rock types and also the land management practice/activity upon it.
Human action has, over a considerable period of time, impacted in various ways on geological and soil resources through activities such as quarrying; the clearance of native woodlands for agriculture; the draining of upland bogs; commercial afforestation and erosion due to recreational activities and overgrazing.
LANDMAP is a tool to help sustainable decision-making and natural resource planning at a range of levels from local to national. Five spatial datasets are included, which are:
- Geological landscape
- Landscape habitats
- Visual and sensory
- Historic landscape
- Cultural landscape
The image below shows the percentage of areas within Snowdonia National Park that are graded as being of high or outstanding quality within their relevant categories.
Regionally Important Geodiversity Sites
RIGS were designated as Regionally Important Geological/Geomorphological Sites in the UK Nature Conservancy “Earth Science Conservation in Great Britain: A Strategy” (1990), being of a standard worthy of recognition and protection as non-statutory sites, to complement the SSSIs and NNRs under statutory protection. RIGS sites in Wales are now known as Regional Geodiversity Sites.
Natural Resources Wales have contributed to the all Wales audit of RIGS through financial and technical support. The audit which began in 2003, is the first comprehensive national assessment of second-tier sites in Wales. It was undertaken largely by the local RIGS groups and NRW Earth Scientists with the majority of the funding coming from the Aggregates Levy Sustainability Fund, but with a financial contribution by NRW to the project in North Wales. The audit led to the standardisation of the site documentation, digitisation of site boundaries to a common format and ensured that the landowners and planning authorities were informed of the RIGS.
A major input from NRW was the development of the GIS database for the project where all of the 600 or so sites registered so far were digitised by NRW. NRW currently hosts these GIS data.
There are 47 RIGS in the National Park.
RIGS Sites within Snowdonia
Location of Working Mineral Sites in Snowdonia
Table 9 presents details of the current working mineral sites in Snowdonia.
|Name of Site||Commodity||Other Mineral Type||National Grid Easting||National Grid Northing|
|Braich Ddu||Slate Waste||Building Stone||271970||338440|
|Craig y Tan||Igneous and Metamorphic rock||Building Stone||271349||336224|
|Ty'n-y-Coed||Slate Waste||Secondary Aggregate||265030||315275|
Working Mineral Sites (Source: Snowdonia National Park Authority)