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HOMERSFIELD PITS
THE EXTENSIVE PIT BETWEEN HOMERSFIELD AND FLIXTON, N.E. SUFFOLK HOWARD MOTTRAM Introduction There are several pits in the area, the identification and working histories of which have recently been reviewed (Holt-Wilson, 2023). In the last 50 years, a lot of the extraction was focused on the land immediately south of the A143 (“Old Railway Road”), in the area between Back Lane in Homersfield and the western edge of Flixton village, a distance of 2.2km, see Fig. 1. There have been a few records of what was exposed in these workings at different periods in time. Since much of the recorded details are unpublished and not accessible on-line, one of the objectives of this article is to bring together some of the information in an accessible format via The Transactions of the Suffolk Naturalists’ Society, initially in printed format and then on-line when the Transactions are uploaded into the ISSUU platform. Although there is a lot of merit in using simple terms such as “Lower Gravels” or “Unit 1”, these terms have already been used by different authors and one author’s usage may not correspond with that of another author. Therefore, caution is required when reconciling the various accounts and, to try and avoid confusion, a simple, perhaps crude, system has been used here for the sediments that have been worked in the pit. The Chalk There are very few boreholes in the vicinity that reach down as far down as the Chalk but a couple of boreholes on the edge of the workings around TM 3025 8672 (BGS refs TM3NW69 and 70) recorded the top surface of the Chalk at about -6m OD. “Basal Crag” Sands that have been described as dark green, greyish green or even of blue-green colouration have been recorded from boreholes and sometimes from excavation. These sands were often shelly and they sometimes had mud bands and, more rarely, thin gravel layers (probably lags). As these sands were usually found below the water table1, useful details on the nature of the bedding and the palaeocurrent directions were not obtainable. The Bottom Half of the Exploited Beds of Sands & Gravels The “Basal Crag” was overlain by other granular sediments; - individual beds of sand and individual beds of mixed sand and gravel, all generally of a pale yellowish colour. Based largely on borehole records, these beds generally commenced at a level in the range of -2 to +2m OD but, in and around the recent workings between Back Lane and Park Drive, the commencement level was at up to +8m OD. 1
The use of the water table as a reference plane requires caution as the natural water table varied from a winter high of +11m OD in the west to a summer low of +9m OD in the east. Also, water could have been perched on areas of clay and, as there was pumping of water between the lagoons that had been created during mineral excavation and processing, the lagoon levels did not necessarily reflect the natural water table level at any location.
Trans. Suffolk Nat. Soc. 59 (2023)