Cwm-Ton, Glascoed
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Geology & landscape
Geological Period: Silurian · Rock Type: Limestone
Description
Description This is an important geological site providing excellent exposures of Silurian rocks, formed about 410 million years ago. The rocks exposed consist mainly of limestones, representing the upper part of the Usk Limestone, overlain by siltstones. The Usk Limestone was traditionally regarded as equivalent in age to the Wenlock Limestone by recent work has led to a revision of this interpretation. These limestones and silts now appear to be Ludlow in age, significantly younger than the Wenlock Limestone and separated from it by an important break in the geological record. This site is therefore of considerable importance in the study of geological events during the Silurian Period at about the junction of the Wenlock and Ludlow series.