Cannel coal systems and low gradient drainage through British Carboniferous mires: informing structural backgrounds, mire longevities, and Pennine Basin palaeoslopes

Abstract

This paper re-introduces a forgotten subject, cannel coal, formed within very low gradient mire drainage systems. A minute part of the British Carboniferous rock volume, cannel was prized in the early Industrial Revolution for oil and gas, notably hydrogen. In this paper it is revisited to reveal under-reported palaeogeography, using modern mining and drilling data to give regional depositional insights. The focus is on the English East Midlands, in the southeast of the Pennine Basin. Early literature on other areas emphasised deposition in small lakes, assuming little connectivity. In the East Midlands, large lake deposits are connected by cannel-filled channels, from the basin's southern margins up to 100km north into Yorkshire. Interplays with fluvio-clastic systems are spread over a subtle but simple palaeoslope, north and northeast to the Gainsborough Trough sub-basin, with negligible structural disturbance during deposition of the Pennine Coal Measures Group. A gentle basement tilt is indicated. Mire drainage tangential to the central basin invites discussion on wider issues, including marine flooding into the basin. Mire longevity is discussed, this also being relevant to research on contaminant contents through coal-forming times.