MS Access 2007- Is this query possible?

[roweco]

I'm sure theres a way to do this, i just cant for the life of me work it out.

i have 2 tables each with the same fields but the data is different and non relational.
tbl structure
ID, Depth, x, y, z
f,0,x,y,z
f,5,x,y,z
f,10,x,y,z
f,15,x,y,z
g,0,x,y,z
g,5,x,y,z
g,10,x,y,z
h,0,x,y,z

tbl 2
f,6.5,x,y,z
f,12.4,x,y,z
g,6.0,x,y,z
h,4.1,x,y,z
h,7.8,x,y,z
h,10.0,x,y,z

I need to make a merge query that will merge all fields in preference.
if for each unique ID tbl 2(depth) is within 5 depth units of table 1 i want it ignored

i have tried doing a merge query with an iif statement but there seems to be a problem as the outcome is just 1000's of 0 depth values for each time an id appears.

hope this makes sense, my first post.