Pennsylvanian (Namurian and Westphalian) miospore assemblages from the west coast of Scotland

Abstract

Examination of cored borehole sections of Pennsylvanian sediments in the Machrihanish Coalfield on Kintyre and samples from coastal exposures at Inninmore Bay on the Sound of Mull, demonstrate the existence of Westphalian (Langsettian to Bolsovian) sediments in both close proximity to the Highland Boundary Fault zone and in isolated outliers within the western parts of the Scottish Highlands. Earlier studies suggested a Duckmantian to Bolsovian age for the Inninmore Bay sections and the investigation of material from new sections in the area confirms this stratigraphical range. The borehole sections in the Machrihanish Coalfield demonstrate the unconformable relationship between the probable Namurian to Westphalian sediments of the Scottish Coal Measures Group and the underlying early Namurian Limestone Coal Formation. In addition to rich assemblages of western European miospore taxa, the Machrihanish populations contain examples of species such as Columinisporites ovalis, Paleospora fragila, Spackmanites irregularis and Vestispora colchesterensis which are characteristic of North American assemblages. The distinctive species Playfordiaspora cancellosa is reported from the British Carboniferous.