This came up and bloomed in an old dirt pile at the back of my property. Does anyone know what it is? It is rather tall, 4 feet or so? has a bit of a silvery look to the foliage, and the flowers smell fruity to me-but just slightly-the scent is not strong.

Looks like one of the everlastings. Sweet everlasting, Pearly everlasting, there are several if memory serves.

Here are the 2 common names mentioned, both different plants.
Sweet Everlasting (Pseudognaphalium obtusifolium)
Pearly Everlasting (Anaphalis margaritacea)

I think a boneset, compare to Late flowering boneset which is just coming into bloom here, where it may be later than in your location
Eupatorium serotinum

That looks more like it. See our database entry for photos
Late Boneset (Eupatorium serotinum)

Thank you!

I've had more or less hunks of it for some years, it can self sow and get big, but it smells good and the pollinators

yes mine is covered in butterflies now!