Revisiting Newall's Mound

Newall's Mound is on the tight bend, just under the words "The Avenue"

Newall’s Mound is a distinctive, low raised hummock located near the "elbow" bend of the Stonehenge Avenue. Named after the pioneering archaeologist Robert Newall, who mapped much of the prehistoric landscape, the mound has been the subject of several archaeological investigations to determine its origin. 

Way back in 2012, I spent some time pondering on txhe origin of Newall's Mound.  Much flood water has gone under the bridge since then,  and on looking at my old post I saw that there is a solution hollow under Newall's Mound.  I was a bit puzzled by that.

https://brian-mountainman.blogspot.com/2012/11/newalls-mound.html

In my post I suggested that on the chalk downlands the solution hollows are the places where the solution of the chalk is most concentrated.  I think my assumption might have been quite wrong.  Having done a lot more reading,  it now seems to me to be much more likely that the solution hollows all over Salisbury Plain are very old indeed, and that they contain residues of ancient deposits that have been broken down and redistributed over hundreds of thousands of years while the "clean chalk" surface on the flanks of the hollows has been systematically lowered by solution.  In other words, there has been in inversion of the topography.  The hollows which were long since the sinks for surface detritus have actually seen a slowing down of the rate of surface solution, which has gone on unchecked elsewhere across the landscape.  

So the hollow becomes a mound, capped by 1.5m of "clay with flints" as we see here in this little feature at Stonehenge.  Sounds absurd?  Not really.  Just think of how kames are formed in glacierized landscapes.  In an ice wastage environment, glaciofluvial materials and associated debris accumulate in hollows in the ice surface.  Glacier ice eventually wastes away completely, and as it does so the old hollows are transformed into hillocks.  The high points in the landscape disappear, leaving befind a veneer of any englacial or supraglaciat deposits that might have been present.  Now substitute chalk for ice, and all is explained.

Topographic inversion and the formation of eskers and kames -- associated with ice wastage

I need to give this more thought........

Interestingly, the mound near the Avenue bend was investigated by Dr John Evans in 1984.  I met John a few times, at a delightful coastal cottage not far from Abermawr in Pembrokeshire.  John was married to Nora Figgis, whom I mentioned on this blog a few days ago.........

Evans,J G. (1984). Stonehenge – the environment in the Late Neolithic and Early Bronze Age and a Beaker-Age burial. Wiltshire Archaeological and Natural History Magazine 78 :7–30.