With this in mind, and referring to the theoretical diagram, 
Plate 1, the method of attack is to shoot a line of reflection pro- 
files radially into the dome, following the deeper sediments up 
slope as far as possible. As the angle of slope of the sediments in- 
creases, the reflection point moves further in toward the dome 
from the vertical, allowing the reflected energy to pass under 
the overhanging upper portion of the salt or caprock, thus secur- 
ing data on the position of sediments actually underlying thick 
sections of salt. 
For cases of relatively thin overhangs or fingers of caprock or 
salt, extending some distance out from the main salt body, there 
exists also the possibility of working through them as though 
they were ordinary beds, of varying thickness. 
It may be well to point out in passing, that the entire success 
or failure of such a determination need not rest on an accurate 
quantitative analysis. For example: An edge well is drilled into 
caprock or salt. By means of such a procedure as outlined above, 
the presence of sediments is shown beneath the depth of the 
well merely by the existence of reflections at greater depth, on 
the record. (Obviously no reflections would be expected within 
the salt core itself.) While quantitative data as to the exact slope 
and depth of these sediments is, of course, greatly to be desired, 
the proving of the mere existence of sediments beneath such a 
well is half the story, and certainly valuable information. 
Reference is given here to an actual case where reflection 
work has been done on the edge of a dome. At the time of this 
work, the question of overhang was not under consideration. A 
subsequent well, however, as seen on the accompanying section 
(See Plate 2), was drilled into caprock within the area below 
which sediments are definitely shown to exist. This would strongly 
indicate the existence of overhang and would suggest the value 
of further study and analysis of the data with this new idea in 
mind. This further study has been started, and while not yet 
complete, there is every indication that further analysis will bear 
out the conclusions drawn and present a very interesting picture. 
As mentioned previously refraction work, by its inherent 
nature, can hardly be expected to contribute any detailed infor- 
mation to such a problem as this. It seems quite probable, however, 
that interesting and worth while general conclusions may be 
drawn in some instances from a closer study of refraction work, 
especially where any considerable amount of it has been done on 
a single dome. Especial attention should be paid in such study 
to relative ‘leads’ on long and short lines, where shot through 
equivalent sections of salt. Obviously, for the commonly assumed 
salt dome shape where the salt section broadens continuously 
13 
