One never really knows about integrity one would try to plan for it should 
it become important
I would suggest a form of coffer process- a rigid liner set in place to hold 
back the sides of the excavation-keeping walls from falling in is hard in 
the best of condition-this could be plywood or boards
-width of material would be determined by expected depth of site. One would 
simply make a box using bolts that could be removed and disassembled. If you 
don’t want to use a ladder in and out could be managed with a door insert 
that would be of several levels
one would let the box drop down as excavation permitted just as in well 
excavation using liners.

sounds like fun

Note also that wet sand is more cooperative than dry- the reverse of land 
practice if you keep it damp it wont tend to fly around and whatever may be 
left of integrity could be better managed.

Conrad Bladey
Professional Archeologist
http://www.cbladey.com/hac/hac.html

-----Original Message----- 
From: Katherine Hull
Sent: Tuesday, October 16, 2012 11:25 AM
To: [log in to unmask]
Subject: Excavation strategy

Good afternoon, folks. Just looking for a little professional advice. We 
will be starting an excavation at the base of the bluffs and along the sandy 
beach of Lake Ontario. Does anyone have any tips re: working in pure sand? 
Our usual approach would be 1x1m test units, but we are wondering if 
trenching (hand-dug, of course) might be a better plan. Vertical control of 
the artifact locations is not imperative as these are secondary deposits at 
the very best. I see depths of deposits being minimal, perhaps 40 cm at the 
most.
Any suggestions would be greatly appreciated.
(at least screening will be a breeze!)
Thanks,
Katie Hull