Tell u r i c prof i1es across t h e Darrough
Known Geothermal Resource Area, Nevada
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BY
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Harold Kaufniann
U.S. Geological Survey
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Open-file Report No. 76-286
1976
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T h i s r e p o r t is preliminary and h a s n o t b e e n
edited o r reviewed f o r conformity w i t h U.S.
Geological Survey standards and nomenclature.
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DISCLAIMER
This report was prepared as an account of work sponsored by an
agency of the United States Government. Neither the United States
Government nor any agency Thereof, nor any of their employees,
makes any warranty, express or implied, or assumes any legal
liability or responsibility for the accuracy, completeness, or
usefulness of any information, apparatus, product, or process
disclosed, or represents that its use would not infringe privately
owned rights. Reference herein to any specific commercial product,
process, or service by trade name, trademark, manufacturer, or
otherwise does not necessarily constitute or imply its endorsement,
recommendation, or favoring by the United States Government or any
agency thereof. The views and opinions of authors expressed herein
do not necessarily state or reflect those of the United States
Government or any agency thereof.
DISCLAIMER
Portions of this document may be illegible in
electronic image products. Images are produced
from the best available original document.
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TELLURIC PROFILES
Darrough, Nevada
Three t e l l u r i c p r o f i l e s were completed across the Darrough, Nevada
K.G.R.A.
One-traverse crossed through t h e c e n t e r of the a r e a from west
t o e a s t , a n o t h e r n e a r the south boundary from west t o e a s t , and one
traverse n e a r the center from s o u t h t o north.
map f o r e x a c t p o s i t i o n s .
See d a t a and l o c a t i o n
Two five-hundred metre lines were used i n a
l i n e a r a r r a y , g i v i n g a s t a t i o n spacing o f one-half km i n t e r v a l .
component between three c o l i n e a r e l e c t r o d e s was used.
Only one
The array was, leap-
frogged along a s t r a i g h t p r o f i l e line t o obtain r u n n i n g r a t i o s of e l e c t r i c
f i e l d amplitudes, a l l referenced back t o the fir,st d i p o l e l o c a t i o n ,
-The s i g n a l was bandpassed fi1t.ered t o limit the p e r i o d t o a 10 t o 60
second range.
The d a t a were recorded on an x-y p l o t t e r and the s l o p e of
the l i n e is proportional t o the r a t i o - o f the e l e c t r i c f i e l d amplitudes
observed between the two dipoles.
The p r o f i l e s for the west t o e a s t t r a v e r s e s a r e shown a t t h e tob o f
the l o c a t i o n map and the sooth t o n o r t h p r o f i l e i s along t h e west edge o f
the map.
The south t o n o r t h t r a v e r s e p a r a l l e l e d the mountain range'and
g i v e s some i n d i c a t i o n of less r e s i t i v e s t r u c t u r e f e a t u r e s a t d e p t h , which
may be i n d i c a t i v e of the east dipping f a u l t (Ferguson and C a t h c a r t , 1954).
The c e n t r a l p r o f i l e also shows a low value n e a r the west end o f the p r o f i l e
which could be related t o the f a u l t i n t h a t a r e a , t h e r e being two high points
on either s i d e of t h e h o t s p r i n g s &rea would i n d i c a t e a perched low resist i v i t y zone r e l a t e d t o t h e h o t s p r i n g s a l t e r a t i o n a t depth w i t h t h e l o w e s t
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p a r t of the p r o f i l e on t h e east end probably reflecting the deeper b a s i n
sediments.
The A.M.T.
27 Hz, t e l l u r i c l i n e n-S r e s i s t i v i t y map s u p p o r t s
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the tel1,uric p r o f i l e very well from t h e Darrough hot springs eastward by
i n d i c a t i n g low r e s i s t i v i t y over the hot springs w i t h a higher r e s i s t i v i t y
ridge s e p a r a t i n g the basin sediments from the area o f the h o t springs.
. The s o u t h p r o f i l e does show a moderate change i n r e s i s t i v i t y just e a s t of
highway 84 n e a r Carvers s t a t i o n , which would be i n the proper l o c a t i o n t o
intersect the east dipping fault.
A f o u r t h t r a v e r s e was attempted near the
north boundary, b u t except for t h e f i r s t two west s t a t i o n s , we were unable
t o obtain a s i g n a l above the noise level.
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Tell uri c Profi 1es-Darrough , Nevada
September 18-22, 1975
Station
1
E l e c t r i c - f i e l d Ratios
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Central t r a v e r s e
(West-East)
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South -N o r t h trave rs e
(South-North)
Angle
y/x r a t i o
Angl e
1
35O
1.36
43.5'
2
45O
1 .oo
3
47'
4
y/x r a t i o
South ern t r a v e r s e
(West -Eas t )
Angle
y/x r a t i o
1.11
56'
0.68
53.0'
0.75
( 34' )
(1.49)
0.93
40.0'
1.18
76'
0.25
38'
1.28
36.0'
1.38
390
1.24
5
45'
1io0
44.0'
1.03
30'
1.74
6
45'
1 .oo
42.0'
1.11
7
37'
1.33
51 .O'
0.81
8
50'
0.84
46.0'
0.96
9
51
0.81
5p.'5
0.82
10
49'
0.87
38.0'
1.28
11
(54')
(0.73)
49.0'
0.87
12
44'
1.03
55.0'
-.
0.70
13
45.0'
1 .oo
14
45.0'
1 .oo
-
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Scale:
1 :62500
Telluric profile with data and location map,
Darrough Hot Springs KGRA, Nevada.
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