:Trefawr Formation

{{Use dmy dates|date=April 2022}}

{{No footnotes|date=June 2020}}

{{Infobox rockunit

| name = Trefawr Formation

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| type = Formation

| age = Silurian

| period = Silurian

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| region = Wales

| country = United Kingdom

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The Trefawr Formation is a geologic formation in Wales. It preserves fossils dating back to the Silurian period.