Is there any possibility that the entire "dump" was in fact what I call a
resource pile?  I've seen lots of these on farms in various locales--a pile
for stones and such (including broken grindstones and brick at times),
another for wooden stuff, another for metal scrap.  Many farmers/ranchers
were very frugal, and figured it all might come in handy some time.  But we
tend to view their "resource piles" as unsightly dumps.  At the
Spencer-Peirce-Little Farm in Newbury, MA, residents in both the 18th and
19th centuries also allowed "dumps" of ceramics and glass to build up to be
used for drainage, in one case in a privy, in another in a fence-ditch.  In
the latter case the sherds and glass fragments probably also kept pesky
groundhogs from digging their way under the fence.

mcb