The Norian Mercia Mudstone Group of west Somerset (England) is dominated by red dolomitic mudstones and siltstones with thin beds of limestone, sandstone, and nodular or discoidal gypsum or celestite. Primary sedimentary structures are poorly preserved in the clastic units, but evidence of bioturbation and pedogenic features, including rootlet traces, is abundant. In contrast, many limestones contain parallel or ripple lamination. At the time of deposition, peloids seem to have been relatively common in the mudstone and carbonate facies. The sedimentary structures, plus the presence of ooids,Botryococcus, and charophyte fragments indicate that the carbonates are of subaqueous origin, but...