The Newall Boulder -- not just weathered, but eroded

In one media piece after another, over the past couple of weeks, on the matter of the Newall Boulder, we have seen statements like this:

Prof Bevins and his team said most of the characteristics cited "could be simply generated by surface weathering".

.........the new research asserts that surface markings previously believed to be glacial abrasion are more likely the result of natural weathering or ancient human handling.

.......wear patterns cited in previous studies as resulting from glacial movement could have actually been caused by natural weathering.

Bevins and colleagues suggest the marks on the stones were not signs of abrasion by the glacier, but were made by human hands coupled with general surface weathering instead.

This is all very weird, and suggests that assorted senior academics do not know the difference between weathering and erosion.  Very strange, since this is one of the things that a student of O level Geography or Geology would be expected to know.  For the record, "weathering" is the term used to cover the in situ breakdown of rock surfaces as a result of physical and chemical processes.  In contrast "erosion" incorporates the movement or transport of material away from its original location, and the use of tools (sand, gravel and larger clasts) in lowering the rock surface.  There are many erosive processes, but abrasion is one of the most important, involving the grinding away of a surface of relatively soft material by ongoing contact with relatively harder "tools".  We might call it the sandpaper effect.  

I cannot imagine why they thought this necessary, but the eleven authors of the recent Newall Boulder tirade appear to be determined to avoid any mention of erosion in their press releases and statements to the media.  So they pretend that the surface of the boulder incorporates some structural elements (describing it as a "joint block" on which all the surfaces coincide with fracture planes) but where the detailed surface characteristics are the result simply of surface weathering.

This is  a serious misrepresentation of the situation. I stand by everything I said in my detailed analysis of the boulder surface.  One face is a fault-controlled feature with slickensides, and some of the other distinct facets may also coincide with joints or other internal weaknesses, but they are clearly abraded, and cannot be explained away as the results of weathering porocesses alone. There are also percussion fractures and fracture scars, some of which might be related to human interference.  The chatter marks are best explained by reference to subglacial processes during ice transport.  There are some slight scratches, but I have refrained from describing them as genuine striations or grooves.  In my paper I describe the weathering features as well.  They are quite complex, but quite distinct from the features associated with erosional history.

For those who seem to be ill-informed on these matters, I can recommend a useful tome, the cover of which I reproduce below.  Other texts are also available.

The literature:

John, B. S. 2024: A bluestone boulder at Stonehenge: implications for the glacial transport theory,
E&G Quaternary Sci. Journal 73, 117–134,

https://doi.org/10.5194/egqsj-73-117-2024

Bevins, R. E., Ixer, R. A., Pearce, N. G., Scourse, J., and Daw, T. 2023: Lithological description and provenancing of a collection of  bluestones from excavations at Stonehenge by William Hawley
in 1924 with implications for the human versus ice transport debate of the monument’s bluestone megaliths, Geoarchaeology, 38, 771–785, 

https://doi.org/10.1002/gea.21971, 2023

Richard E. Bevins, Nick J.G. Pearce, Rob A. Ixer, James Scourse, Tim Daw, Mike Parker Pearson, Mike Pitts, David Field, Duncan Pirrie, Ian Saunders, Matthew Power, 2025.  The enigmatic ‘Newall boulder’ excavated at Stonehenge in 1924: New data and correcting the record,
Journal of Archaeological Science: Reports, Volume 66, 2025, 105303,
ISSN 2352-409X,

 
https://doi.org/10.1016/j.jasrep.2025.105303

Victorian gifts: new insights into the Stonehenge bluestones
Rob Ixer, Richard Bevins, Nick Pearce, and David Dawson explain more. 2022.
CURRENT ARCHAEOLOGY, AUGUST 29, 2022, 5 pp

https://the-past.com/feature/victorian-gifts-new-insights-into-the-stonehenge-bluestones/

Streamlining, Blidö, Sweden

 

 

Nice pic from one of my kayaking trips this summer.  There is not much doubt in this area about the direction of ice movement -- all the features associated with glacial erosion point to ice movement pretty well exactly north to south......