Repetitive ERTS-1 imagery covering Utah and Nevada is studied as an aid in structural geology, mineral exploration, and limnological and hydrological aspects. Limnological features of algal blooms and varying biological activities in Utah Lake and the Great Salt Lake are grossly evident on the imagery with more subtle details detected on the different bands. Major structural breaks, lineages, or trends are abundant throughout the area of study. The correlation of positive aeromagnetic anomalies with the trends suggests near surface intrusive bodies, not yet exposed at the surface, that can be tested for possible associated mineralization by collecting soil-gas at the surface which is analyzed for mercury that is (1) apparently associated with mineralization, (2) escapes as a vapor, and (3) can be readily measured in extremely low amounts of less than 1 ppb by absorption

Jensen, M. L.

English

NASA Technical Reports Server

Paper G 3 
GEOLOGY OF UTAH AND NEVADA BY ERTS-1 IMAGERY 
Mead LeRoy Jensen, Depart~mnt of Geological and Geophysical Sciences, 
University of Utah, Salt Lake Ci:y, Utah 841 12 
Abstract 
" nepetst i ; .~ EKTE-? imgt!ty covering Utah and Nevada i s  being 
studied as an aid i n  s t r u c t u r a l  g;eology, rnineral exploration,  and llmnological 
and hydrological aspects.  
Limnological fea tures  of a l g a l  blooms and varying biological  a c t i v i t i e s  
i n  Utah Lake and the  Great Sa l t  Lake are  grossly evident on the imagery with 
more sub t l e  d e t a i l s  detected on the d i f fe ren t  bands. 
Major s t r u c t u r a l  breaks, i i n e a ~ e s ,  or  trends ace abundant throughout 
the area of study. The cor re la t ion  of posi t ive  aeromagn~?tic anomalies with the 
trends suggests near surface in t rus ive  bodies, not y e t  e:cposed a t  the surface,  
tha t  caa be t e s t ed  f o r  possible associated minera l iza t io~l  by col lec t ing s ' ~ i 1 -  
gas a t  the surface which is  analyzed fo r  mercury tha t  2s (1) apparently aa- 
sociatea si th  mineralizatlon,  (2 )  escapes as  a vapor, and (3)  caa be readi ly  
measured i n  extremely low anol~ztn of l e s s  than 1 ppb by ~ b s o r b t i o n .  
I n i t i a l  s tudiee are proving t h a t  the ERTS images show lineament 
trends and some of these lineament8 do r e l e ~ s e  anomalous !lg contents and are  
prime zones f o r  fu r the r  inineral exploration study. 
Orlglnal Plctography may tt purchased fr,m 
247 EROS Data Cenier 
~ R E C D W G  PAGE BLANK NOT mWBD 10th and Gahota A;\?nue 
Sioux Falls, SP 57198 
https://ntrs.nasa.gov/search.jsp?R=19730019503 2020-03-17T09:03:08+00:00Z
In t  roduc t 102 
The prime objectives of NASA ERTS-1 Contract L'N 113, of wnich I am 
the Pr incipal  Investigator,  per ta in  t o  mineral resources and exploratioc,  
and s t r u c t u r a l  geology. Limnological observations are  a l s o  proving t o  be 
in teres t ing.  The area of coverage Ls large extending over a l l  of Utah, most 
of Nevada, and portions of California and WymonFng. The boundaries of t h i s  
rectangular area are  from 37" t o  42" N l a t i tude  and from 109' t o  119' W 
longitude. 
Geologically and physiographicaliy, the area  includes diverse provinces, 
v iz . ,  Colorado Plateau, Uintah Mountains, Wasatch Mountains, Green River and 
Uintah basins,  a port ion of the  Sierra  Nevada slid a l l  of the northern portion 
of the Basin and Range province. The diversLty of mineral and o i l  depoaits ,  
ws of formations and igneous rocks, and the va r i a t ion  i n  s t r u c t u r a l  fea tures  
provide a vas t  po ten t i a l  f c r  the p r a c t i c a l  apgl ica t ion of mult iepectral  imagery 
t o  the study of t h i s  area. SpeciEic areae of w r e  deta i led  study a r e  indicated. 
Imegery 
Only bulk MSS imagery i e  being used i n  a l l  four bands. The i n i t i a l  
rtudy i r  great ly  enhanced by viewing with a Nikkon binocular microscope mounted tt 
;-, 
over a l i g h t  table  and used t o  view the poeit ive transparent films a t  10X t o  :: 
80X. The former magnifications is best  a s  i t  o f fe re  a l a rge r  area of rtudy but 
. . 
r t i l l  with re tent ion of d e t a i l s  on the imagery. 
Those imager t h a t  provide area8 o r  feature8 of g rea tes t  i n i t i a l  
i n t e r e r t  a r e  fu r the r  enhanced when printed i n  B 6 W but enlarged four t i ~ r  . . 
a rca le  of  about 11250,000. In te re r t ing ly  enough, l i t t l e  d e t a i l  i r  loot  wick 
248 
the enlargement and numerous geological nape of the area are  available a t  
the same scale  A prime example is  Humbolt County, Nevada, where regional  
s t ruc tu ra l  trends,  basin and range normal f a u l t s ,  t ransverse (essen t i a l ly  E.W) 
i a , ~ l t s  and spec i f i c  l i thologic  types can be recognized on the imagery while 
some are  not noted on the geologicel map. The enlarged ERTS-1 image i s  
perfectly adeqaate as  a base map and could have served readi ly  as  a f i e l d  
hase map for  mapping. 
A simple method of producing color composites and aingle-color 
band-images i s  being used. This involves the  use of Diazochrome color  films 
i n  an Ozalid contact  copier.  The method i s  rapid,  simple, and r e l a t i v e l y  
inexpensive. The superposed f i l m  r e s u l t  i n  a color  transparency which can be 
re-photographed by 35 mm o r  o ther  cameras t o  produce excellent  projection 
materials .  The superposed fi lms can be used d i r e c t l y  on overhead projectcrs  
or  viewed with l i g h t  tables .  We find tha t  some experimenting i s  required 
with t h i s  technique because of the var ia t ion8 i n  the density of the iaagery 
6;s the need t o  use the proper co lo r  of diazochrome with epeci f ic  bands. 
Generally, tl:e l ighzer pas te l  colors  provide far bettet  f a l s e  color enhanced 
imagery. Examples w i l l  be shown with 35 nm colored r l ides .  
Hydrologic Featurea 
Two ancient watercouraer have been observed on ERTS-1 imagery. 
These l i e  i n  the  Waterpocket Fold area ,  north of the  Marble Canyon rect ion of the  
K 
Colorado River, i n  Atitona and Utah. The old  watercour8e appear8 t o  have baan :' 
! '\, 1 \ 
northward flowing, following the Waterpocket Fold west of the  Henry Uunta;lnr, 
1 
of the ryrtem, The wrtercourre can be obrerved on image No, 1032-17370, A 
cutoff meander on the Colorado River, r t i l l  above the prerent level  of Lake 
Powell, rpperrr  t o  be of r irnilrr  rgr m d  porribly re la ted to  the ancient 
wrteraourrr, Tho major part  of the path of the watercourse appean to be 
r t r u c t u r r l l y  controlled. Thr t r i b u t r r i r r  ganerrl ly flow northwrrtwrrd and 
northrrrtwrrd md i n t r r r r c t  Lhr major r i v r r r  with the rcuta rnglr  r r  i f  the 
mrfor r tn rmt  rtlll flowed northwud rather thrn routhwud. 
A rraond old wrtrraourrr  cm boat br rarn  i n  th r  v ic in i ty  of Lon8 
Rid8r and tha am Juan Rivrr on lmrgr No. 1031-17313, 
A remarkable c o r r r l a t i o n  of the mncgl  p rec ip i t r t ion  on the Uintrh 
Brrin i r  evident by comparing image No. E 1121-17312-4 with r computer generated 
rhadrd map (Fig, 1) of the  r a m  area. Tho remarkable r i m i l a r i t y  of the 
boundrrier of the loweot ?rc;ipitat ion are evident. 
Limnolonical Featured 
Inugr No. 1051-17414 contr inr  romr vary u r e t u l  informtior .  oc- 
arrning t h r  hydrology, rrdimmtology, and biology of Great S a l t  Lrkr A L ~  Brrr 
Lrkr i n  Utah, The Rrrrtrr p r n r t r r t i o n  of wrvrlrngthr i n  brad 4 of the WB 
lnugrry y i r l d r  much infornution rbout rrdiaunt p l w r  and wrtrr depth. Band 5, 
with lrrrrr penr t r r t ian ,  g ivrr  morr infomat ion rbout rurfroa phrndmrna, in- 
cludin# a l g a l  populrtionr , a t e ,  Tho i n f r r r r d  brndr providr infornution rbout 
rhrllow wrtrr i n  m r r h  rrrrr whre th r  wrtrr i r  hidden Cram rhortrr-wrvrlrrqth 
bmdr by v ra r t r t ion .  In  Orrrt Brlt L J r ,  t h r r r  i r  a rhrrp  linr brtwrrn t h r  
por t ioa  of t h r  lrkai north of tho ra i l road crurrwry, whkh i a  r r r r n t i a l l y  r r w k  
a d  orrthorn d m ,  a d  t h a t  routh of t h  arurowry (Pfi. 2), , There i e  I markod 
d i f fa r rncr  i n  r r l i n i t y  8ororr  the r a u r m y ,  and t h i r  i r  r r f l r a t r d  Ln d i f f r r r n t  
2so 
a l g a l  spec i e s ,  p l a in ly  v i s i b l e  i n  band 5. A reddish a lgae  occupy the  nor th  
limb, while blue-green v a r i e t i e s  occupy the  south l i m b .  The negative water 
budget i n  the  nor th  limb causes br ine  concentrat ion i n  t h a t  a r e a ,  accompanied 
by northward sur face  flow through the two narrow openings i n  th* causeway. This  
flow can be seen i n  band 5. The high dens i ty  i n  the  nor thern  limb r e s u l t s  i n  
dens i ty-current  counterflow a t  depths ,  and t h i s  can be seen i n  band 4. The 
sediment plumes from inflowing r i v e r s  a r e  p l a in ly  v i s i b l e  on bands 4 and 5.  
These f ea tu re s  a re  enhanced i n  the f a l s e  co lo r  images a s  shown by 35 mm s tud ie s .  
Image No. 1051-17420 conta ins  parc of Great S a l t  Lake and a l l  of 
Utah Lake. The l a t t e r  d i sp l ays  a  very i n t e r e s t i n g  sur face  pa t t e rn  which i s  
probahly due t o  an a l g a l  bloom which has been swirled i n t o  a  s p i r a l  by the 
c i r c u l a t i o n  of the lake.  This  was a shor t - l ived  phenomenon observed on the  
September 12 overpass only which has not been observed on o the r  imagery t o  
da te .  The a l g a l  nature of t he  phenomenon is  not ye t  proven but  i s  t o  be 
s tudied  i n  cooperat ion with ERTS-1 l i m o l o g i s t s  of the  National  Oceanic and 
Atmospheric Admids t r a t ion  who f i r s t  noted t h i s  f e a t u r e  a; shown in Fig. 3. 
Geological Features 
The prime geologica l  f ea tu re s  t h a t  a r e  most obvious i n  t he  area  a r e  
major s t r u c t u r a l  t r ends ,  lineaments, o r  s t r u c t u r a l  breaks. These a re  most 
prevalent  i n  t h e  Wasatch and Basin and Range provinces. The majori ty have 
never been recognized before ERTS-1 imagery and they provide an explora t ion  
p o t e n t i a l  of  major s igni f icance .  This  i s  t h e  app l i ca t ion  of geochemical and 
geophysical study over t rends  t h a t  extend i n t o  a l l u v i a l  or volcanic a reas  
t h a t  a r e  post-mineral izat ion i n  age and hide evidence of p o t e n t i a l l y  
mineral ized a reas  below the  overburden. 
25 1 
As there i s  s ign i f i can t  evidence tha t  mercury vapor escapes from 
mineralized zones, soil-gas samples are col lec ted i n  the post-ore blankets 
over the inferred extension of mineralized trends using a hood equipped 
with a fan tha t  forces the a j r  thrcagh 80 mesh s i l v e r  screen. The amalgon 
is  l a t e r  heated i n  the laboratory and the quantity of released Hg i s  measured 
by an atomic absorption instrument. Such s tud ies  have been done over known 
mineralized zones with s ignif icant  I4.g amounts of about 400 ppb t o  > 1000 ppb 
have been measured while samples collected over pr2sumably mineral barren 
zones assay generally i n  the range of < 300 ppb of Hg. 
It r s  o, lr  des i re  t o  locate Hg soil-gas anomalies i n  post-ore 
covered zones and perform cursory induced polar iza t ion surveys o l e r  the 
amonalies with the hope of detecting su l f ide  mineralization a t  depth. The 
p rac t i ca l  significance of t h i s  application of ERTS-1 imagery i n  cor re la t ive  
s t u d i e s  with known geotechnics is  qu i t e  obvious. 
In teres t ingly  enough, besides the evident mineralization exposed i n  
bed rock adjacent t o  the a l l u v i a l  f i l l e d  val leys ,  aeromagnetic maps a re  a l so  
used as addit ional  ground t r u t h  and are  of a id  i n  cnr re la t ing  the lineages 
and trends with posi t ive  aeromagnetic anomalies. This  i s  especia l ly  t rue  i n  
north cen t ra l  Nevada where in t rus ives  have presumably given r i s e  t o  mineral 
deposits  i n  favorable carbonate rocks underlying major th rus t  f a u l t s .  The 
overlying rocks of the t h ~ u s t s  conoist o f  e s s e n t i a l l y  s i l i ceous  and volcanic 
formatione tha t  a r e  comparatively non-reactive t o  mineralizing f lu ids .  
I n  conclurion, therefore,  r t r u c t u r a l  breaks detected oa ERTS imagery 
m y  t a rge t  trends tha t  co r re la te  with pos i t ive  aexomagnetic anomalies where 
anomalous Hg content i n  soil-gar fu r the r  del ineate  where jaduced po la r i t a t ion  
rurveyr should be done with the  hope of detecthtng r u l f i d e  depor i t r  f o r  which 
there  i r  no surface evadence other  than the  , .-ience on the  ERTS imagery. 
252 
0 - 6 inches 
6 - 10 
10 - 14 
14 - 18 
18 - 22 
22 - 26 
26 - 30 
30 - 34 
34 and above 
Figure 1 

Figure 3 


Geology of Utah and Nevada by ERTS-1 imagery

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