Three types of remote sensing data (Airborne Imaging Spectroscopy (AIS), NS001, Zeiss IR-photographs) were obtained for the Moses Rock kimberlite dike in southern Utah. The goal is to identify and characterize the mantle derived mafic component in such volcanic features. The Zeiss and NS001 images provide information on the regional setting and allow units of the dike to be distinguished from surrounding material. A potential unmapped satellite dike was identified. The AIS data provide characterizing information of the surface composition of the dike. Serpentized olivine-bearing soils are (tentatively) identified from the AIS spectra for a few areas within the dike

Mustard, J. F.

Pieters, C. M.

English

NASA Technical Reports Server

N86-11635 
SPECTROSCOPY OF MOSES ROCK KIMBERLITE DIATREME 
CARLE M. PIETERS and JOHN F. MUSTARD, Department of Geologieel Sciences, Brown 
University, Providence RI 02912 
ABSTRACT: Three types of remote sensing ditto (AIS, NSOO I, Zeiss 
IR-photo;raphs) were obtained for the Moses Rock kimberlite dike In 
southern Utah. OUr pi Is to Iclmt1fy and charooterlze the mantle derlvaj 
mefic component in such volcanic features. The le'iss and NSOO 1 Images 
provide information on the regiOMI setting and allow units of the dike to be . 
distinguished from surrounding material. A potential unmapped satellite 
dike was identified. The AIS data prov\de chara:teri2ing information on the 
surfa oomposition of the dike. Serpentized olivine-bearing soils are 
(tentatively) identified from the AIS spectra for a few arees within the 
dike. 
Introduction 
A number of small kimberlite-bearing diatremes of Tertiary age recur on the Coloraoo 
Plateau. The origin of these unusual volcanic features is not well unoorst<XXt, but Is believed to be 
assooiated with mantle prooesses that result in a rapid rise of material from the mantle through 
the continental crust. Although such an event (presumably explosive) has never been directly 
observed, kimberlite-bearing volcanic features are a valuable source of otherwise Inaccessible 
m8fltle and crustal rocks of great interest to the geochem ist (and sometimes a source of diamonds 
for the investor). KimberHte-bearlng features have not been explored extensively with remote 
sensing techniques primarily because of their small size and because their Identifying 
ch8rooterlstics have not been well OOcumented. 
The Moses Rock dike in southern Utah was chosen for analysis with the Airborne Imaging 
Spectrometer (AIS). Rocks, breccias, and deposits of the dike have been mapped in detail 
( 1: 12000) by McGetchin ( 1968, unpublished). A schematic geologic map of Moses Rock dike and 
observed rock types were presented by Mc6etchln and Stiver ( 1970, 1972) w!th a dl~usslon of 
the mlnerolO1l(, petrolOll( and geochemistry of the mantle-derived mater loIs (summorized In 
Geology section below). -
OUr pi In sttxt(lng Moses Rock Dike with AIS data Is to Identify Gild charooterlze the 
mantle-derived mafic and ultramafic material. These types of rocl\s and minerals are known to 
exhibit charooteristic absorption bands near I urn as weH as bands be!;woon 1.6 and 2.5 um due 
largely to iron and other transition metals in their crystal structur-e (eg. Mlms 1974, 1975; 
Hunt end Salisbury, 1970). If successful, this type of dat.a will prGvide a significant exploration 
tool to be used not only in IrenUfylng these unusual volcanic structures, but also for unraveling 
the norm811y complex distribution of material w'ithin thb'm. 
. The flight over the Moses Rrek target area in Monument V811ey was flown July 20, 1984. 
~t8 oollected Included Zeiss oolor infrared photographs, NSOO 1 (TN simulator) multispectral 
images, and AIS deta. The day was clear and cloudless. Analysis of these deta commenced January 
1985, and a preliminary discussion of results is presented below. A few system problems 
occurred on our flight: the nevlglltion system (INS) was not functioning properly and could not 
provide accurate positioning of the aircraft, the Nlkon camera was inoperative, and the clocks on 
the ZeiSS end NSOO 1 were either loopefaUve or Inaccurate. 
106 
https://ntrs.nasa.gov/search.jsp?R=19860002168 2020-03-23T06:30:22+00:00Z
Geology of the Moses Rock Dike 
(from Mc6etchln, 1968; Hc6etchln and Sliver 1970, 1972) 
Hoses Rock dike is a breccia-ftlled. ktmberltte-bearino dl8treme lreated In the Colora» 
PJateDU of south-eastern Utah. It Is hooked-shaped In plan and Dbout 6 km in length. It intrudes 
the undeformed and unmetamorphosed sandstone, siltstone and limestone of the Permlen CUtler 
formation. The dike cont~t Is sharp and the walls are steep. A system of JOints extends out Into 
the host rooks parallel to the dike cont~t. Hoses Rock dike occurs In a cluster of diatremes 
southeast of the Monument uplift (a large regional anticline) and along the axis of the Comb Ridge 
monocline. Superlm~ on the regional structure are a series of north-south trending 
anticlines and synclines. Total structural relief 00es not exceed 1500 meters and is concentrated 
. along the Comb Ridge monocline. 
The majority of the dike consists of large blocks up to several hundred meters across 
derived from the Cutler formation of sYldstones exposed tn the vent walls. The interstices between 
the lar~ blooks are ftlled with a matrix of unconsoltdated br8lCla. This matrix Is composed of 
fregments from the large blocks, limestone fragments, crystalline rook fragments, and mafic and 
ultramafic const i tuents. 
Kimberlite, which constitutes 8bout I~ of the dike, oocurs as small bOOles not larger than 
10 meters in diameter. It is a hj~ly serpentinized, ultramafic microbreccia containingoJivine, 
pyroxene. garnet. phlO(J)pite and spinel. Most of the primary mineralow is relict after 
serpentine and chlorite. These mineral consutuents and alteration products are found dispersed 
throujlout the breccia matrix. Haterial derived from kimberlite constitutes about 121 of the 
breccias. About 31 of the breccia consists of Igneous. altered Igneous. and foliated metamorphic 
rocks derived from the b8S8ment. Oense ultr8l1ltlfic mantle-derived fr8gments, which include 
eclogite, lherzolite, websterite, and jolte-pyroxenite, are rare. The distinctly comminuted 
texture, the absence of sil1cate melt. and the dispersion of kimberlite material throughout the 
breccia indicates that the dike was emplaced as a fluidized volatile and solid particle system driven 
by H2O and CO2. The source of the k Imber lite m8lJlla has been estimated to have been at a depth in 
excess of 100 km. 
Zeiss Infrared Photographs 
The Zeiss camera used color infra-red ftJm with a spectral range of 510-900 nm. The 
field of view is approximately 7 kilometers with a ground resolution of about 1-2 meters. These 
hl~-QU8lity stereo images provide a regional perspective of the fJlght Jines and f~i1nate mapping 
of fine structural features. These images were our primary data for looating the ground tr~ks of 
both the NSOO 1 and AIS data. The high-resolution 80d stereo viewing allow the Influences of 
topolTaphy and texture to be assessOO. 
East and South of Moses Rook the Permian beds dip moderately fI'Nff./ from the dike towards 
an are6 of fJat- lying TriassiC and Jurassic sandstones. Where the Navajo sandstone Is exposed a 
prominent set of parallel joints is visible. They are oriented approximately ESE/WNW and are 
regularly spaced at 50 to 100 meter intervals with no apparent offset along the jOints. The 
orientation of the joints Is orttlOljJ)nal to the axis of the Monument uplift and Comb RiOJa which 
implies the joints are a result of the regional stresses that existaj during the formation of the 
uplift end monoollne. There are elso scattered lineations oriented about 60 degrees to the joints 
8I1d localized circular and curvl- linear fr~ture patterns in the same formation. These are 
~ttributed to 10081 structural response due to stratigraphic if'regularities in the regional stress 
environment. 
On the basts of texture and color In the Zeiss Images, Hoses Rock dike Is divided Into three 
units; the head, the bcOt, and the tan. The apparent color of ~ unit Is distinctive in the IR 
107 
photqaphs: pale blue, green, and grf1« to b Ius-grey. The heed is comp lex and coarsely textured. 
On the east marain of the head a 1000 linear feeler dike intersects two eHipttcel mounds of uniform 
debris. In the ~, large looal1y derlv'" breccia blooks ere surrounded by a motU"', bri~t 
matrix. The taU Is characterized by a uniform fine-grained texture and an absence of breccia 
blocks. 900 meters east of the tal1 Is a small e111ptlC81 zone aboUt 300 meters tn length with the 
long exls oriented ~anel to the tmiing. It is simn8l" in texture and apparent color to the ten, 
and mav be 8 previously undet~t.., satell ite dike. 
NSOO 1 (TM Simulator) 
Airborne slmulat.., thematic mepper (NSOOJ) dlaital d8ta were examined to quantify the 
quts1ttatlve observations from the Zeiss images. Ratio Images were prepared and principal 
component analysis (PCA) images were studied in this prel1minary examination to better define 
the general nature of Moses Rock dike ~ weH as potenUal sateH ite dikes. 
It is app8f"ent by visual inspection thot the units of the dike show the greatest spectral 
variation in the first five TM bands. Many ratios were examined and it was found that the ratios 
of bands 2 (0.53-0.60 ~m) to 5 (1.00-1.35 ~m) and bands 3 (0.63-0.69 ~m) to 5 (1.00-1.35 
JIm) best differentiate the dike units. In both images the tail has a uniformly high ratio while the 
heOO and bOOt show an irregular distribution of regions with a hiOh ratio. Q)mparisons of these 
regions to the Zeiss images show thet they occur in the interstices between breccia blocks. 
Kimberlitic mineral components and alteration products are found dispersed throughout the 
matrix (see Geology sectton) , and may lI:COunt for the observed disttnction in the raUo Images. 
Further comparison with the geologic mop of Moses Rock (Mc6etchin, 1968) shows that the 
regions with the highest ratios cor'r'espond very weH with the units mapped as containing the most 
serpentine in the matrix. Some beds within the Cutler formation, however, exhibit comparable 
ratiQ values and may also be a significant component of the matrix. The potential sate11ite dike 
Unfortunately lies along one of these beds and was unresolv8ble in the ratio images. 
PCA of the first six thematic mapper bands was 00ne to further classify the dike. The 
program used ~ts up to six input images and by a linear transformation of the variables 
proouees Images of the first three principle components. Although the results of the PCA are at 
the moment preliminary and qualitative, the third principle component image clearly shows that 
the "satellite dike" is similar in nature to the tail and different than the sedimentary units 
sur'roundlng tt. With further analysts of the principal component tmages tn conjunction with the 
ratio images, we expect to obtain a better understanding of unit distinctions within the Moses Rock 
area. 
Airborne Imaging Spectrometer (AIS) 
Six of seven short AIS swaths did cross the Moses Rock dike target. Five of these were in 
the 'rook' mme (about 1.15 to 2.35~m); one was In the 'tree' mme (about 0.86 to 2.04~m). 
Date processing was performed at JPL using the s~ialized, but versetUe, software Pfdcege 
'SPAM' developed by J. Solomon. When this useful package is incorporated into the VAX-based 
VlCAR2 paage, we will continue AIS enaJysls using our fecnttles 8t BraNn. 
A'S Dota As§essnent. 
Although the data from this f1i~t were lOquate to determine thot useful spectroscopiC 
Information is indeed obtainable for kimberlite-bearing surfaces (see below), there were' 8 
number of ulldetermined instrumental or calibration problems thrJt made the precision, and 
possibly accuracy, of the data lower than it should be. Serious line":to-line (spatial) banding was 
108 
p .... 
observed for about half the spectral channels. Banding in one channel was correllated with banding 
In neljlboring channels. For a few channels along-track stripping was also present. These effects 
Idi!Id amiderable noise to the spectroscopic meesurements of pixel ,-oops and could not be 
removed without destrating most spatial information. 
Data analysis dealt largely with 'relative reflectance spectra' prOOUced by raUolng the 
_rum of an area of interest to the spectrum of a standard area (chosen as representat ive of 
10081 soil around the dike). This p~ has the mtvantage of anowing instrumental and 
atmospheric effects to be cancellEd (except in saturoted water bands). To obtain true reflectmce 
spectra, the standard area needs to be calibrated independently. For these preliminary analyses 
wei have assumed that the spectral ch8r~ter of the standard soil Is relatively featureless. 
(Anttcipeted field work this summer will check this.) 
Once distinctive spectrosmpf~ areas were identified (see below). the SPAM 'find' function 
was empla,red on the type spectrum (original, not raUDed) to estimate areal extent of a unit within 
ths AIS swath. 
AIS Data Analysjs. 
Within the ltmlts of this flIght of data, two distinct units with well-defined spectroscopIc 
features were identified in uUlion to the more spaliaHy extensive 10081 st8nd8rd. The vast 
majority of surfa material covered in the AIS swath is not greatly different from our chosen 
standard. 
The first of the spectroscopic units is in the dike and is what we have tentatively {'.ailed 
Moses Rock 'kimberlite'. The type area was chosen based on the unpubl1shed map of McGetchin 
(1968). This type are8 W8S crossed by AIS swaths of both spectroscopic mroes allowing its 
spectral ch8r~ter to be examined from 0.86 to 2.35 um. The 'kimberlite' area exhibits two 
spectral features: 1) a band that begins relatively sharply at about 2.25 um and Increases In 
absorption (up to 8bout 251) toward 2.35um; and 2) a brotll band of similiar strength between 
0.86 and 1.50~m with an 8Pparent center near 1.15um. These features are consistent with 
serpenttzed olivine-bearing rooks or soH, currently our preferred interpretation. For 
comparison our "k Imber lite" relative spectrum Is presented In F fgure I, and 8 serpet1Uzed olivine 
reflectance spectrum from Hunt and Salisbury ( 1970) is presented in Figure 2, 
0:11 1.00 '.15 1.)0 1.45 t.IO 1.11 t.1O 2.0~ 2,20 2.31 
wavelell9lh - micron. 
Figure 1. AIS spectra from combined 'rook' and 'tree' 
modes for our st8flderd area (AIS, rfIN calibrated 
spectrum) and the 'kimberlite' erea(Rklmb. reflectance 
spectrum relative to the standDrd area spectrum)~ 
109 
j 
I'! 100 ~ 
ti 
-' 
.... 
II: 
~ 50 
Iil 
-' ~ 
~ 0L-~1.0-=·~1~.5~-2~.0~-2~.5 
II! WAVELENGTH IN MICRONS 
Figure 2. Reflectance spectra of 
serpentlzed olivine (from Hunt and 
Salisbury, 1970) 
The second spectroscopiC unit occurs as a lecal soil type east of the dike that exhibits a 
week bend (about 7r«) between 2.1 md 2.35um, centered nee.- 2.2um [and perhaps another 
feature hicbln by the 1.9um atmospheric water bend]. We inter-prete this as soil containino an 
abundance of a hydrated minerai (currently undefined). 
Summary of Results 
Although we have not yet thoroughly analyZElt the Interrelation between the AIS, NSOO I, 
and Zeiss deta, It is clearly import8l1t to have coordinated data: one type of deta is needed that is 
Optimized for mapping surfas (such as the NSOO 1 and Zeiss) and allows material of oenerally 
slmner cMracteristics to be identified md mapped ewer IDrge oreas; and MOther type of d8to is 
needed that is optimized for characterization of surface material (such as AIS) and allows 
spectflc composlttonallnformatton to be determ tned. The AIS data has produced spectra that can be 
,'nterpreted directly in terms of mineral components. Mafic material at Moses Rock dike has 
tentatively been identified and interpreted as serpentiZElt olivine-bearing soils (confirmation 
awaiting field work). The NSOO I Images have not only allowed the necessary regional overview, 
but have also identified EOIitional areas in the region that may be associated with the dike. 
Mttttonai AIS fHghts and/or field work for these areas will clarify the 8SSOCtatton. 
Recommendat ions 
High-spectral resolution mapping spectrometers prewlde Important Information about the 
composition of surface materials. The AIS is a glad, if not excellent, prototype of such 
instruments. Major areas of impl"'ewement that would strongly enhanrA3 and enable science 
applications Include: I) more complete spectral coverage leg. 0.5 to 2.5um1 I 2) higher 
accuracy and precision [largely a function of instrument calibration and noise control], 3} wider 
swath width [or at least continU8tion of coordinated multispectral imeolno ewer a wider ares). 
References: 
Adams J. B. (1974) Visible and near-infrared diffuse reflectance spectra of pyroxenes as applied to 
remote sensing of solid objects in the solar system. J. (Jeophys. Res., 79. 4829-3636. 
Adams J. 8. (1975) Interpretation of visible and near-infrared diffuse reflectance spectra of 
pyroxenes and other rock-forming minerals. In: Infrlred Ind Rlmln Spectt:0scopy of 
Lunlr Ind Terres/ril/ /"Ilteril/s (C. Karr. Ed.) Academic Press. New York. 91-116. 
Hunt. G. R. and Salisbury. J.W. (1970) Visible and near-infrared spectra of minerals and rocks: I Silicate 
minerals. /"I()dern (Je()/()IY, V()I. /.283-300. 
McGetchin T. R. (1966) The Moses Rock dike: Geolooy. petrology. and mode of emplacement of a 
kimberlit.e-bearing breccia dike. San Juan County. Utah. Ph.D. thesis. 405 pp .• Calif. lost. of 
Technol .• Pasadena. 
McGetchln T. R. and Silver l. T. (1970) Compositional relations In minerals from kimberlite and related 
rocks in the Moses Rock Dike. San Juan County. Utah. The Americln /"Iinerl/()Iist, V()I. 
55. 1737-1771. 
McGet.chln T. R. and Silver L. T. (1972) A crustal-upper mantle model for the Colorado Plateau bned 
on observations of crystalline rock fragments In the Moses Rock Dike. J. (Je()phys. Res., 77. 
7022-7037. 
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Spectroscopy of Moses Rock Kimberlite Diatreme

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