Soft-rock conservation in action

摘要

Situated in the heart of England, eastern Warwickshire is well known for its Quaternary glacial deposits, comprising tills, fluvial sands and gravels. Professor Fred Shotton first recognized a clear stratigraphy in the 1950s, and he subsequently proposed the local succession as the type-Wolstonian. Since then, ongoing exposure in working sand and gravel pits has led to many new sedimentological, palaeontological and archaeological discoveries. Several classic disused sites are now afforded statutory protection as Sites of Special Scientific Interest. However these pose real conservation challenges, given the rapidly degrading nature of the unconsolidated strata, once exposed. Recently, the Warwickshire Geological Conservation Group (WGCG) obtained funding from the Aggregates Levy Sustainability Fund to pilot a soft-rock conservation scheme at a working pit -Wood Farm quarry near Bubbenhall, south of Coventry, operated by Smiths Concrete Ltd. There, the Thrussington Till overlies the Baginton Sand and Gravel. When freshly excavated, the sections present an amazing range of sedimentary and other geological features, but rapidly degrade. The WGCG's project worker, Dr Clark Friend, identified a suitable section that was cleaned up, graded and stabilized through the co-operation and efforts of John Green, quarry manager. Through liaison with the WGCG's Conservation sub-committee, Clark designed and sourced a waterproof cover (vehicle tarpaulin sheeting) that has been pinned down over the section. Now that the cover is in place (Fig. 2), the WGCG aims to periodically monitor the section, to assess the viability of this technique and its applicability to other soft-rock sites.