RESEARCH· ·1970·

B56
GEOPHYSICS
STRATIGRAPHY
AND
LITHOLOGY
STRATIGRAPHY
AND
LITHOLOGY
400
600
800
1000
1200
1600
1800
2600
3300
1
I
Density from 1
density log
I
I
I
I
......
I
._ 1
I
I
01
I
I
L
Density from borehole
gravity meter data
1
L...,
I
I
I
I
I
I
I
-,
I
I
I
I
I
I
I
0
J
oo 1
...:
0 c.J
E
:::1
"> 'ii
=
~
'ii ~
>. .:
"' c:
~
I
~
:::1
8
0 ...,
"C
rtf
~ 0
..... 8
>. N'
iV a:
:e Cl)
Q)
.....
(I)
e
;
c.J £
·c:
~
~ ~
~
c.J
>. ~
iV 0
>.
'€ .r:
Q) a::
.....
"C
~~
"C::I
Gl-
CQ
3400
3600
3800
0 0
0
L...,
r.....J
Saturated bulk density
4000
determined from core L .,
b rJ
4200 0
4400
4600
4800
5000
I
I
I
5200 10
I
I
5400 I
I
, .......
5600
--,
r'O""'
,J 0
L--,
5800
Lo_,
I
.... J
6000 op
._,
01
6200
0 .I
r--J
-....,o
6400 I
r-_,
Total depth of hole: 6,514 feet
l!l:GURE 3.-0alculated illlterval in s•itu bulk densities from borehole gravity meter and density log data, with laboratocy
analysis of·co•re, drill hole UOe--18, Hot Greek Valley, Nev. Lithology modified from R. P. Snyder (unpub, data).
6600
-,'
penetrated rocks and is also considerably influenced
by 'hole rugosity which affects the positioning of the
tool against the side of the hole and, consequently, its
precision. None of these factors, however, influence the
borehole gravity meter. The density determined from
the gravity data is the average value for all the rocks
in this interval, out to a radius approximately equivalent
to five times the interval thickness (l\1cCulloh,
1966, p. 4). This factor tends to average the borehole
gravity n1eter data.
The saturated bulk density data determined by
laboratory analysis of core versus depth are plotted on
figure 3. These data also exhibit considerable scatter,
which is not unexpected because the densities are determined
on individual cores from rocks that are not
homogeneous.