Calciferous Sandstone Series Sedimentation at the Eastern End of the Midland Valley of Scotland

Abstract

ABSTRACT The East Fife Mississippian sedimentary succession is predominantly deltaic in origin. On-delta, delta-front platform, delta slope, and pro-delta shelf facies can be recognized. On-delta sediments include coals, seat earths, and sandstones occupying various sizes of cut-and-fills. The delta-front platform deposits are for the most part medium to fine grained, planar cross-bedded sandstones interbedded with siltstones and shales containing ostracods and non-marine lamellibranchs. Contorted, slump bedding is widespread in the delta slope sandstones and siltstones, as are small scale cut-and-fills and flow casts. Mottled and laminated siltstones interbedded with calci-lutites, shelly calcarenites and shales characterize the pro-delta shelf facies. At intervals the delta facies were partially or completely inundated by marine waters advancing from the south. The sediments laid down on these occasions include marine intraclastic and biogenic limestones, and shales. In West Lothian, lagoonal sedimentation at the margins of the main delta complex was more common (oil shales, oolitic, sun-cracked and mottled limestones). Marine transgressions are more difficult to detect. The petrography of the sandstones in both areas suggests very active erosion of nearby mountain sources composed chiefly of pre-existing sediments. The most important source lay to the north and north-east.