Geography and geology
High Weald, Low Weald and Greensand Ridge
To understand an area's vernacular buildings we must understand its geology. Before canals, and then railways, transformed the carriage of heavy goods, only local building materials were affordable for most people. And it was the local geology that determined what materials these were.
Oak was the abundant material in the Weald, thanks to the clay soils on which oak trees thrive.
So almost all vernacular Wealden buildings used oak for timber frames, clay for tiles and wattle-and-daub walls, and sandstone outcrops for masonry plinths and walls, as well as clay for bricks.
The map shows the three main areas:
- The High Weald in the centre (areas of light green in the centre of the map). This is mostly hard sandstone rock with very poor soils, but there are complex local outcrops that make it important to check a detailed geology map. The many fast-running streams have cut deep, narrow valleys, known as ghylls, which are usually heavily wooded. The High Weald includes Lancaster Great Park formed in 1372, renamed as Ashdown Forest in 1672. The High Weald Area of Outstanding Natural Beauty (AONB) has good online videos about its geology, landscapes and settlements.
- The Low Weald round the northern, western and southern edges of the High Weald (darker green). This is mainly Weald clay with some softer sandstones, and is often still characterised by small pastures and meadows, shaws and thick hedgerows.
- The Greensand Ridge which stretches around the north and west of the Weald (light blue and turquoise). The Greensand, green only when first exposed, and weathering to a golden yellow, includes the Weald's highest points.