Graptolites from a thin anoxic within the siltstone/oxic grey mudstone transition between the Moffat Shales proper (Birkhill Shales) and Gala Group greywackes at Selcoth Burn, Moffatdale

Graptolites occur within a thin anoxic mudstone horizon, midway through several metres of oxic grey mudstones and siltstones that separate the Moffat Shale Group proper (i.e. the black anoxic mudstones with bentonites of the Birkhill Shales) from sandstones of the overlying Gala Group, at Selcoth Burn in Moffatdale (at National Grid Reference NT 1575 0619). The lithostratigraphical setting and the graptolite fauna is very similar to that known from Pot Burn in the Ettrick Valley, the graptolites indicating the gemmatus subzone of the guerichi Biozone (lower Telychian, upper Llandovery). The find indicates the importance of searching for graptolites in uncompromising, predominantly oxic siltstone/mudstone sequences where these occur between the Moffat Shales and overlying sandstones.