This may be a repeat of an earlier query from someone else,
but I am trying to get some information about protecting
in-situ historical artifacts located about 1 1/2 to 2 feet
below the surface.  The final use of the site will be as a
parking area for everyday vehicles
 
(1)  Which is better for the artifacts, gravel fill (with a
geothermal (I believe that is the term) liner) OR a concrete
pad?
 
(2)  If a gravel fill, how thick should it be for the best
protection?
 
Prior testing revealed that artifacts down to about a foot
below the ground surface were heavily fragmented, but below
that were some large, intact remains, especially faunal
material.    This area was previously used as an informal
parking area.
 
Thanks.
 
Doreen Cooper, Klondike Gold Rush NHP, Skagway, Alaska