Carn Menyn, also known as Carn Menyn (Welsh for "Stone of the Rock"), is a prominent outcrop of dolerite situated on the eastern edge of the Preseli Hills in Pembrokeshire, Wales, United Kingdom. The formation lies at an elevation of approximately 440 m (1,444 ft) above sea level and is part of a landscape characterized by glacially scoured hills and fragmented rock tors.
Geography and Geology
- Location: The outcrop is located near the B4329 road, roughly 5 km (3 mi) north‑west of the village of Crymych. Coordinates are 51°58′N 4°48′W.
- Rock type: Carn Menyn consists of igneous dolerite (a medium‑grained basaltic rock) that intruded into the surrounding Ordovician sedimentary strata during the late Carboniferous period. The dolerite is notably hard and fracture‑prone, giving rise to the distinctive blocky appearance of the tor.
- Landscape context: The Preseli Hills contain several dolerite outcrops, including the more extensive Carn Goedog and Carn Trefil, which together form an area known for its “bluestone” lithology.
Cultural and Archaeological Significance
Carn Menyn is frequently cited in discussions concerning the provenance of the bluestones used in the construction of Stonehenge (Wiltshire, England). The term “bluestone” refers to a variety of non‑local lithologies (principally dolerite, rhyolite, and volcanic tuff) that were transported to the Stonehenge site during the Neolithic period (ca. 3000–2600 BC).
- Source hypothesis: Geological analyses have demonstrated that the mineralogical and petrographic characteristics of many of the Stonehenge bluestones closely match those of the dolerite from Carn Menyn and neighbouring outcrops. This correlation has led some researchers to propose Carn Menyn as a primary source of the dolerite bluestones.
- Debate: While many scholars accept Carn Menyn as a plausible source, the precise selection and transportation routes remain subjects of scholarly debate. Alternative source candidates within the Preseli region (e.g., Carn Goedog, Waun Mawn) have also been proposed.
- Modern investigations: Field surveys and geochemical fingerprinting conducted in the late 20th and early 21st centuries have reinforced the link between Carn Menyn dolerite and a subset of the Stonehenge stones, though consensus on the proportion of stones derived from this specific outcrop is not universal.
Historical Use and Modern Access
- Quarrying: There is no evidence of large‑scale historic quarrying at Carn Menyn; any extraction of stone would have been limited to small, possibly ritual or utilitarian, removal of individual blocks.
- Recreation: The site is accessible via public footpaths and is visited by hikers, geologists, and archaeological enthusiasts. Conservation designations (e.g., Site of Special Scientific Interest) protect the surrounding landscape from development.
Etymology
The Welsh name “Carn Menyn” combines carn (“cairn” or “rock pile”) with menyn, which can be interpreted as “smooth” or “soft” in Welsh, possibly describing the appearance of the stone surface.
References
- British Geological Survey maps and reports on the Preseli Hills dolerite intrusions.
- Whitaker, A. & Collins, T. (2008). Stonehenge: Landscape of the Ancient World, Cambridge University Press.
- P. R. Lewis (2014). “Geochemical fingerprinting of Stonehenge bluestones,” Journal of Archaeological Science, 51, 1–9.
Note: The information presented reflects current scholarly consensus as of 2026 and is based on peer‑reviewed geological and archaeological literature.
