Mineral Exploration Using Modern Remote Sensing Techniques by John L. Berry John Berry Assocs Beverly Hills Dr. AUSTIN, TX

ASTER DEM & Draped Image John Berry Assocs Beverly Hills Dr. AUSTIN, TX Bands 1,2,3 CompositeASTER DEM ASTER DEM with Contours Oblique View of Band 1,2,3 composite draped over DEM

Comparison of ASTER Bands (bottom) with TM bands (top). Note multiple narrow ASTER bands where TM has one broad band in SWIR and TIR. John Berry Assocs Beverly Hills Dr. AUSTIN, TX

Landsat TM and ASTER SWIR Band Coverage of Clay Mineral Spectra. ASTER can resolve Kaolinite, Alunite, Illite, etc.. John Berry Assocs Beverly Hills Dr. AUSTIN, TX

John Berry Assocs Beverly Hills Dr. AUSTIN, TX

John Berry Assocs Beverly Hills Dr. AUSTIN, TX Standard USGS reference spectra for Na-Sericite, K-sericite, phengite and Mg/Fe phengite in the SWIR region, showing the progressive shift of the absorption band position to longer wavelengths (left). The same spectra convolved to the ASTER band configuration showing the variation in the shape of the 2209 nm absorption band for the same minerals (right) (Courtesy AD, Inc., website)

John Berry Assocs Beverly Hills Dr. AUSTIN, TX Emissivity Spectra of Common Rocks showing shift in emissivity low from 8.6 um (ASTER Band 11) for granite to 10.7 um (ASTER Band 13) for dunite. This shift forms the basis for using the thermal bands of ASTER to map lithology

John Berry Assocs Beverly Hills Dr. AUSTIN, TX Thermal emissivity spectra of some important minerals convolved with the ASTER thermal bands, superimposed on each other by normal- izing to a value of 1.0 at 8.0 um (Band 10). The spectral curves differ even more than those for rocks. Thus alteration zones char- acterized by these minerals can be map- ped using ASTER TIR.

John Berry Assocs Beverly Hills Dr. AUSTIN, TX Green Red Minerals are widely separated on this plot, and would show up as green (Dunite) to orange (Albite) if Band 13 were assigned to Greeen and Band 12 to Red.

John Berry Assocs Beverly Hills Dr. AUSTIN, TX The linear distribution shows that there is a strong correlation between the emisssivity spectra of different minerals in bands 13 and 14, a phen- omenon that is also seen in the SWIR region, but for vegetation spectra. This means that in an image, dunite (olivine) would be dark and quartz would be bright, but they would have the same color. This is therefore NOT a good band combination Using ratio composites (next slide) helps to spread the data points out in color space, giving better discrimination

John Berry Assocs Beverly Hills Dr. AUSTIN, TX This is actually an enlarged section of a ternary diagram, but Excel will not display it as such. It shows that good separation of the minerals in color space can be achieved using Thermal band ratios.

This image shows different ages of lava flow - the youngest being the whitest. The overall variation in the image is from red to green, with little blue: this reflects the linearity of the distribution of points on the previous slide. The N-S dark line on the east edge appears to be a fault in alluvium. John Berry Assocs Beverly Hills Dr. AUSTIN, TX Ethiopian Rift Valley Thermal image

Khoy Ophiolite, NW Iran. ASTER Bands 3,2,1 draped over DEM Ophiolite nappes are at left John Berry Assocs Beverly Hills Dr. AUSTIN, TX

John Berry Assocs Beverly Hills Dr. AUSTIN, TX Bands 7,3,1, ASTER Composite Khoy Area: ASTER composite compared to Geological Map. Note the greater amount of detail on the image in the Ultramafics at lower left

John Berry Assocs Beverly Hills Dr. AUSTIN, TX NW-trending Nappes Basalts Ultramafic Rocks Khoy Tectonic Mélanges

Left: 7,3,1 Composite. Red Box outlines area of next 2 slides. Blue Box outlines the slide after that Right: 4/7-3/4-2/1 Abram Band Ratio Composite John Berry Assocs Beverly Hills Dr. AUSTIN, TX

John Berry Assocs Beverly Hills Dr. AUSTIN, TX KHOY, IRAN: Composite, showing Tectonic Windows and Related Folds

John Berry Assocs Beverly Hills Dr. AUSTIN, TX John Berry Assocs Beverly Hills Dr. AUSTIN, TX KHOY, IRAN: ASTER Band Ratios, showing Tectonic winows and related Folds

E-MORB OIB Band Ratio 4/7-3/4-2/1 composite distinguishes Ocean Island Basalt (OIB) from mid-Ocean Ridge (MORB) Basalt