Palaeoenvironmental and stratigraphic significance of worm burrow linings from the Lower Oil-Shale Group (Dinantian) of West Lothian

Abstract

In an earlier paper, one of us drew attention to tube-like microproblematica as unusual, but potentially valuable, environmental and stratigraphic indicators in British Jurassic lagoonal deposits ([Andrews 1986][1]). In this note we develop the theme of the earlier paper by describing tube-like microproblematica in Upper Palaeozoic rocks, the Lower Oil-Shale Group of Dinantian age, in West Lothian, Central Scotland. It is suggested that shallow-lagoonal environments have been important habitats for small infaunal worms during much of Phanerozoic time. The Oil-Shale Group rocks mainly represent deposition of fluvio-deltaic and non-marine lagoonal sediments and the lithologies are dominated by sandstones, shales and dolostones. Although occasional, thin, marine horizons occur (e.g. the Pumpherston Shell-Bed), fossil assemblages are dominated by fish remains, bivalves, gastropods, conchostracans, spirorbid worms, ostracodes, cyanobacteria, calcareous green- and phytoplanktonic-algae, representing a non-marine fauna and flora. Tube-like microproblematica have been known from the Lower Oil Shale Group of West Lothian for almost a century ([Cadell 1906][2]; [Carruthers 1912][3]; [Greensmith 1960][4]; [Loftus 1985][5]). They occur in the Queensferry Beds of [Mitchell and Mykura (1962)][6] including dolostones (the ‘Bogwood Limestones’ of [Loftus 1985][5]) some ten metres below the Burdiehouse Limestone, the base of which divides the Upper and Lower Oil Shale Groups ([Francis 1983][7]). The tubes are seen at two localities, beds 1 and 68 of [Maddox and Andrews (1987][8], Fig. 4) on the southern foreshore of the Firth of Forth at South Queensferry [NT 140 785], and beds 1 and 52 on the southern foreshore of the Firth of Forth near Hopetoun . . . [1]: #ref-1 [2]: #ref-2 [3]: #ref-3 [4]: #ref-6 [5]: #ref-8 [6]: #ref-10 [7]: #ref-5 [8]: #ref-9