- Cefn-cerig Road
Cefn-cerig Road, a road near Cefn-cerig Farm,
Llandovery ,Wales , is the location of theGlobal Boundary Stratotype Section and Point (GSSP) which marks the boundary between theAeronian andTelychian stages of theSilurian period on thegeologic time scale . The GSSP was ratified in 1984.The boundary is defined as a point immediately above the highest record of the
brachiopod "Eocoelia intermedia" and below the first appearance of the succeeding species "Eocoelia curtisi". The boundary also corresponds to the incoming of theacritarch s "Deunffia monospinosa", "Domasia bispinosa" and "Pterospermella". The section, part of theWormwood Formation , issandstone andsiltstone .References
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