GEOLOGY
The rocks underlying the woodlands of the Gleadless Valley belong to the Coal Measures and were formed between 325 and 280 million years ago, during the Carboniferous period of geological time.

The rocks consist of alternating bands of shale and sandstone, with shales generally being dominant.

Snow in one of the Gleadless Valley woodlands.

LANDSCAPE
The Lumb occupies a narrow valley, this being the origin of its unusual name, 'lumm' being the Saxon word for a steep-sided valley.

The stream in the valley bottom is a tributary of the Meers Brook, the main watercourse in the Gleadless Valley. It emerges from an artificial culvert at the southern tip of the woodland and, like most of the smaller streams in the Gleadless Valley, is generally shallow and narrow. However, the amount of water in the stream can vary considerably from season to season. In dry periods, it can almost disappear whilst after wet weather, runoff from surrounding land can cause it to become very full and fast flowing.

SOILS
Three main soil types underlie the woodlands of the Gleadless Valley: acidic soils, neutral soils and waterlogged soils.

Thin dry 'acidic soils' occur over sandstone, particularly on higher ground, as well as over shales on steep slopes. The depth and acidity of the soils is strongly affected by slope, with the thinnest and most acid soils being found on steeply sloping sites. Deeper and less acidic soils occur on flatter ground, even over sandstone.

Neutral soils are mainly found on flat to moderately sloping ground over shales. They vary in depth and clay content and also from dry to seasonally wet, the wettest areas being on stream banks, in valley bottoms and by springs and wet nutrient rich areas known as flushes.