Ice Age Tiger Stripes That Inspired Stonehenge?

 

This Google Earth image (dated 27 September 2018, coordinates approx. 52°29'19.20"N 0°39'19.20"E) captures Grime’s Graves in Norfolk from above. The Neolithic flint mine pits appear as circular depressions in the foreground field, while the large open area behind shows clear parallel bands of alternating vegetation — the classic Breckland periglacial stripes (also called tiger stripes). These stripes run across a gentle slope, visible as lighter and darker bands in the grass/heath.

Key Facts About the Stripes at Grime’s Graves

• Formed during the Devensian Stage (last Ice Age, ending ~11,700 years ago) through freeze-thaw cycles, frost cracking, solifluction, and cryoturbation on Upper Chalk bedrock.
• On gentle slopes (1–6°), polygons on flat ground transition into parallel stripes spaced ~7–8 m apart.
• Wind-blown coversand (acidic) infills frost-crack gullies, supporting heather; intervening chalky soil supports grass — creating strong pH and vegetation contrast.
• Confirmed by 2016–17 GPR, boreholes, and soil pits at the adjacent GRIM military training site: tripartite deposits (pellet chalk, gravelly diamicton, chalk rubble) with coversand in gullies.
• Still highly visible today in aerial views and lightly grazed areas; English Heritage notes these “vegetation stripes” as a Breckland speciality, best seen looking north-west from the site (some areas in a danger zone).

Identical Features at Stonehenge

• Excavations along the Stonehenge Avenue revealed parallel periglacial fissures/grooves in the chalk bedrock, formed by the same Devensian processes.
• These align roughly with the midsummer sunrise/midwinter sunset axis.
• Stonehenge Riverside Project researchers (e.g., Mike Parker Pearson, Mike Allen) suggest the natural stripes may have been noticeable to Neolithic people and influenced site selection.

Why the Grime’s Graves Photo Helps Reconstruct the Neolithic View at Stonehenge

• Shared origin: Both sites overlie Upper Chalk subjected to identical periglacial conditions; the stripes are relict patterned ground.
• Better modern preservation at Grime’s Graves: Thick Devensian coversand creates sharp acidic/alkaline contrast that drives vivid heather-grass bands. Salisbury Plain lacks this widespread coversand layer.
• Neolithic conditions at Stonehenge (~3000 BC):
  • Soils thinner: Holocene chalk dissolution and minor truncation estimated at ~0.3 m over ~4,000–5,000 years; Neolithic topsoil was shallower, bringing fissures closer to the surface.
  • Fresher micro-relief: Less time for bioturbation, grazing, and colluviation to smooth contrasts.
  • Differential vegetation likely: In dry summers, silt-filled grooves would support taller/darker grass versus shorter turf on chalk ridges — producing visible parallel lines similar to those in the Google Earth image.
• Homogenisation over time at Stonehenge: Patchy prehistoric cultivation, loess redistribution, and 5,000+ years of pastoral management dulled the surface expression. Today the Avenue stripes are subtle and mainly visible in excavations.
• Breckland as analogue: The photo shows the same Ice Age patterning still expressing strongly in vegetation. Remove modern heather, thin the turf, and sharpen the relief — and you approximate what Neolithic observers would have seen on Salisbury Plain: natural “lines in the grass” leading toward the solstice.

In short, the two photos of Grime’s Graves provide one of the clearest modern snapshots of active-looking periglacial stripes. They strongly suggest that 5,000 years ago the equivalent features at Stonehenge would have been much more obvious on the open chalk downland.

References

• Boreham, S. & Rolfe, C.J. (2016–17). “Imaging periglacial stripes using ground penetrating radar at the ‘GRIM’ training site, Grime’s Graves, Breckland, Norfolk.” Bulletin of the Geological Society of Norfolk 66: 31–43.
• English Heritage guidance on Grime’s Graves (Ice Age stripes description).
• Allen, M.J. et al. (2016). “Stonehenge’s Avenue and Bluestonehenge.” Antiquity.
• Geoarchaeological reports on Holocene soil development and truncation on Salisbury Plain chalk downlands.