The provenance, petrology and sedimentology of building stone in Bromyard, Herefordshire, UK

摘要

A multi-disciplinary study was undertaken of the Lower Old Red Sandstone building stones of Bromyard, Bromyard Downs and Bringsty Common, Herefordshire, UK, to trace their original quarry sources. 196 stone structures were recorded in detail and 3 broad lithological groups recognised. Combining old maps, archival sources, Light Detection and Ranging (LiDAR) data and testimony of local residents, the historic quarries in the area have been mapped. Field studies of the geology of quarries and outcrops have established the area of origin of two distinctive coarse grained lithologies. Intraformational conglomerates have been demonstrated, with some confidence, to be derived from Bromyard itself. Coarse, pebbly, quartzose sandstones have been traced to Bringsty Common and shown to be used only in the church in Bromyard before the 20th century. The origins of fine grained sandstone are found to be more complex. Through a combination of fieldwork and archival research, Clater Park Quarry is indicated as the origin of high quality green sandstones in Bromyard. 15 samples of sandstone from the Bromyard Downs, have been petrographically analysed by point counting to determine their clastic and mineralogical proportions. Early results of this analysis are presented which show modal variation in lithics, feldspars and cements that may serve to link quarries to buildings. Finally, it is suggested that at least some of the diversity of stone present in Bromyard is the result of slight variation in depositional processes in the immediately underlying bedrock. (C) 2016 The Geologists' Association. Published by Elsevier Ltd. All rights reserved.