I think that giving some thought to the Marlborough Mound and Silbaby could be helpful when thinking about the 'function' of Silbury, if indeed the people at the start of the construction had a specific function in mind.
It seems curious that another mound (Silbaby) should be required so close to Silbury. Or was it? Was Silbaby an abandoned project in favour of Silbury? If that was so you might imagine Silbaby would have been levelled.
Or perhaps Silbaby IS finished and at the required height for whatever purpose?
Theres too many unknowables.
