Chapter 3B. Analysis of Imaging Spectrometer Data for the 

Badakhshan Area of Interest

By Todd M. Hoefen and Michaela R. Johnson

Abstract

Imaging spectrometer data collected over the Badakhshan area of interest (AOI) in northeastern 

Afghanistan were analyzed with spectroscopic methods to identify the occurrence of selected material

classes at the surface. Absorption features in the spectra of HyMap data were compared to a reference 

library of spectra of known materials. The HyMap data in this AOI is limited by the northern and eastern

limits of the dataset. Thus, less than one-half of the AOI has HyMap coverage. The presence of 

abundant dry vegetation, which has masked the surficial minerals in a significant and geologically 

important part of the area, have reduced the utility of the hyperspectral data for overall site 

characterization in the Badakhshan AOI. Carbonates, muscovite, illite, and vegetation cover most of the 

region. Distinct patterns of chlorite or epidote, muscovite, illite, dolomite, and serpentine occur in 

localized patterns throughout. Many of the faulted areas in the region have associated dolomite, epidote 

or chlorite, and serpentine. In the iron-bearing map, vegetation covers much of the surface mineralogy. 

Fe2+ Fe3+ Type 2, epidote, and Fe3+ Type 1 are found in concentrations throughout most of the 

southwestern region of the AOI. It should be noted that the distance from a ground calibration target 

combined with the high elevation of the region results in residual atmospheric bands, which can affect

the accuracy of results in this region. Some of the rocks in this region also lack significant amounts of 

minerals with diagnostic absorption features in the wavelengths covered by the HyMap sensor. Future 

field work to the area could result in an improvement in the overall calibration of the area and 

understanding of the minerals within the Badakhshan AOI. 

3B.1 Introduction

Past studies of geologic data of Afghanistan revealed numerous areas with indications of 

potential mineral resources of various types (Peters and others, 2007; Abdullah and others, 1977).

Several of these were selected for follow-on studies using imaging spectroscopy to characterize surface 

materials. Imaging spectroscopy is an advanced type of remote sensing which is also known as 

hyperspectral remote sensing. One of those areas is the Badakhshan area of interest (AOI) in 

northeastern Afghanistan, which is approximately 350 kilometers north-northeast of Kabul (fig. 3B–1).

The area is believed to have the potential for metamorphic gold vein, gold-copper skarn, iron skarn, and 

polymetallic vein deposits. To help assess these potential resources, high-resolution imaging 

spectrometer data were analyzed to detect the presence of selected minerals that may be indicative of 

past mineralization processes. This report contains the results of the spectroscopic data analyses and 

identifies sites within the Badakhshan AOI that warrant further investigation, especially detailed 

geological mapping, lithologic sampling, and geochemical studies.

3B.2 Data Collection and Processing

In 2007, imaging spectrometer data were acquired over most of Afghanistan as part of the 

U.S. Geological Survey (USGS) project "Oil and Gas Resources Assessment of the Katawaz and 

Helmand Basins.” These data were collected to characterize surface materials in support of assessments 

of resources (coal, water, minerals, oil, and gas) and earthquake hazards in the country (King and others, 

2010). Imaging spectrometers measure the reflectance of visible and near-infrared light from the Earth’s 
Chapter 3B. Hyperspectral Mapping Analysis for the Badakhshan Area of Interest 187

surface in many narrow channels, producing a reflectance spectrum for each image pixel. These 

reflectance spectra can be interpreted to identify absorption features that arise from specific chemical 

transitions and molecular bonds that provide compositional information about surface materials.

Imaging spectrometer data can be used only to characterize the upper surface materials and not 

subsurface composition or structure. Subsurface processes can be indicated, however, by the distribution 

of surface materials. 

Figure 3B–1.

3B.2.1 Collection of Imaging Spectrometer Data

The HyMap imaging spectrometer (Cocks and others, 1998) was flown in Afghanistan from 

August 22 to October 2, 2007 (Kokaly and others, 2008). HyMap has 512 cross-track pixels and covers 

the wavelength range 0.43 to 2.48 micrometers (μm) in 128 channels. The imaging spectrometer was 

flown on a WB-57 high-altitude aircraft at 50,000 feet. There were 207 standard data flight lines and 

11 cross-cutting calibration lines collected over Afghanistan for a total of 218 flight lines, covering a 

surface area of 438,012 square kilometers (km2) (Kokaly and others, 2008). Data were received in scaled 

radiance form (calibrated to National Institute of Standards and Technology reference materials). Before 

processing, four channels that had low signal-to-noise ratios and (or) were in wavelength regions 

overlapped by adjacent detectors were removed from the HyMap data (image cubes). Each flight line 

was georeferenced to Landsat base imagery in Universal Transverse Mercator (UTM) projection (Davis, 

2007). 

Index map of the Badakhshan area of interest, northeastern Afghanistan.
188 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

3B.2.2 Calibration

HyMap data were converted from radiance to reflectance using a multi-step calibration process. 

This process removed the influence of the solar irradiance function, atmospheric absorptions, and 

residual instrument artifacts, resulting in reflectance spectra that have spectral features that arise from 

the material composition of the surface. Because of the extreme topographic relief and restricted access 

to ground calibration sites, modifications to the standard USGS calibration procedures were required to 

calibrate the 2007 Afghanistan HyMap dataset (Hoefen and others, 2010). 

In the first step of the calibration process, the radiance data were converted to apparent surface 

reflectance using the radiative transfer correction program Atmospheric CORrection Now (ACORN; 

ImSpec LLC, Palmdale, CA). The ACORN program was run multiple times for each flight line, using 

average elevations in 100-meter (m) increments, covering the range of minimum to maximum elevation 

within the flight line. A single atmospherically corrected image was assembled from these elevationincremented ACORN results. This was done by determining the elevation of each HyMap pixel and 

selecting the atmospherically corrected pixel from the 100-m increment closest to that elevation. 

Each assembled atmospherically corrected image was further empirically adjusted using groundbased reflectance measurements from a ground calibration site. Spectra of five ground calibration sites

were collected in Afghanistan: field spectra from Kandahar Air Field, Bagram Air Base, and

Mazar-e-Sharif Airport, as well as laboratory spectra of soil samples from two fallow fields in Kabul. 

These were used to calculate empirical correction factors using the pixels of atmospherically corrected 

HyMap data in the flight lines that passed over the sites. The empirical correction from the closest 

calibration site to each flight line was applied. 

To further improve the data quality, an additional calibration step was taken to address the 

atmospheric differences caused, in part, by the large distances between the calibration sites and the 

survey areas. The large distances were a result of the lack of safe access to ground calibration sites. The 

duration of the airborne survey and variation in time of day during which flight lines were acquired also 

resulted in differences in atmospheric conditions between standard flight lines and lines over ground 

calibration sites, which were used to derive the empirical correction factors. Over the course of the data 

collection, the sun angle, atmospheric water vapor, and atmospheric scattering differed for each flight 

line. To compensate for this variation, cross-cutting calibration flight lines over the ground calibration 

areas were acquired (Kokaly and others, 2008) and used to refine the data quality of the standard data 

lines. A multiplier correction for each standard data line, typically oriented north-south, was derived 

using the pixels of overlap with the well-calibrated cross-cutting line that intersected it, subject to slope, 

vegetation cover, and other restrictions on pixel selection (Hoefen and others, 2010). As a result, the 

localized cross-calibration multiplier, derived from the overlap region, corrected residual atmospheric 

contamination in the imaging spectrometer data that may have been present after the ground calibration 

step. 

While the cross-calibration procedure was successful for the Afghanistan dataset, the 

Badakhshan AOI is located in one of the more remote areas of Afghanistan. Because of its remote 

location, no ground calibration targets were measured within the region. The cross-calibration 

corrections limit atmospheric residuals to the best of our ability but the high elevations in this area 

combined with the lack of a nearby calibration site result in data that could benefit from additional 

information collected in future field excursions and a local calibration site. 

3B.2.3 Materials Maps and Presentation

After undergoing a complex and rigorous data calibration process, the georeferenced and 

calibrated reflectance data were analyzed using the Material Identification and Characterization 

Algorithm (MICA), a module of the USGS Processing Routines in IDL for Spectroscopic Measurements 

(PRISM) software (Kokaly, 2011). The MICA analysis compared the reflectance spectrum of each pixel 

of HyMap data to entries in a reference spectral library of minerals, vegetation, water, and other 

materials. The HyMap data were compared to 97 reference spectra of well-characterized mineral and 
Chapter 3B. Hyperspectral Mapping Analysis for the Badakhshan Area of Interest 189

material standards. The best spectral match to each pixel was determined and the results were clustered 

into classes of materials discussed below. The resulting maps of material distribution, resampled to a 

23 x 23 square meter pixel grid, were mosaicked to create thematic maps of surface mineral occurrences

over the full dataset covering Afghanistan. 

The MICA module was applied to HyMap data twice to present the distribution of two categories 

of minerals that are naturally separated in the wavelength regions of their primary absorption features. 

MICA was applied using the subset of minerals with absorption features in (1) the visible and nearinfrared wavelength region, producing the 1-μm map of iron-bearing minerals and other materials (King 

and others, 2011), and (2) in the shortwave infrared region to produce the 2-μm map of carbonates, 

phyllosilicates, sulfates, altered minerals, and other materials (Kokaly and others, 2011). For clarity of 

presentation, some individual classes in these two maps were bundled by combining selected mineral 

types (for example, all montmorillonites or all kaolinites) and representing them with the same color in 

order to reduce the number of colors required to represent the mineral classes. 

The iron-bearing minerals map includes 28 classes. Iron-bearing minerals with different mineral 

compositions but similar broad spectral features are difficult to classify as specific mineral species. 

Thus, generic spectral classes, including several minerals with similar absorption features, such as 

Fe3+ Type 1 and Fe3+ Type 2, are depicted on the map. The carbonates, phyllosilicates, sulfates, and 

altered minerals map has 32 classes. Minerals with slightly different mineral compositions but 

comparable spectral features are less easily distinguished; therefore, some identified classes consist of 

several minerals with similar spectra, such as the “chlorite or epidote” class. When comparisons with 

reference spectra resulted in no viable match, a designation of “not classified” was assigned to a pixel.

3B.3 Geologic Setting of the Badakhshan AOI

The Badakhshan AOI is within Badakhshan Province in northeastern Afghanistan. The main 

Badakhshan AOI is 6,500 km2, of which the Fayz Abad District subarea covers 1,270 km2. The Ragh 

and Bharak District subareas are not covered by the HyMap dataset and are not discussed in this chapter. 

The contrast-enhanced stretch of the natural color composite of Landsat Thematic Mapper bands shown 

in figure 3B–2 provides a general overview of the Badakhshan AOI terrain and is useful for 

understanding the general characteristics and distribution of surficial material, including rocks and soil, 

unconsolidated sediments, vegetation, and hydrologic features.

3B.3.1 Topography

Land elevation within the Badakhshan AOI ranges from 577 to 4,605 m (fig. 3B–3). The lowest 

areas within the Badakhshan AOI are in the river basin in the southern region of the AOI. The highest 

areas are found in the central and northeastern regions of the AOI. The three population centers within 

the AOI are the province center of Fayzabad and the two district centers of Ragh and Baharak.

3B.3.2 Lithology and Structure

The Badakhshan AOI contains known low-sulfide gold-quartz occurrences and associated 

deposits in northern Badakhshan Province that are hosted in Proterozoic and cover rocks that mainly are 

Early Proterozoic biotite-amphibolite, garnet-biotite gneiss, migmatite, quartzite, and marble. Rocks in 

the Badakhshan area range in age from Early Proterozoic to Late Quaternary and Recent. Intrusive rocks 

of Proterozoic, Mississippian, Permian, Early Triassic and Oligocene age occur within the AOI. The 

Proterozoic, Mississippian, Permian and Early Triassic intrusive rocks predominantly occur in the 

western half of the AOI. The Oligocene intrusive rocks occur in the eastern half with only small sections 

having overlapping hyperspectral data. Older Precambrian rocks occur along heavily faulted terrain and 

are trending from the southwest to northeast. Mesozoic and Paleozoic rocks occur throughout the AOI. 

Cenozoic rocks generally occur in the northwest region of the AOI with the exception of Late 

Quaternary and Recent age rocks that are present within the river basins of the area (fig. 3B–4; Abdullah 

and Chmyriov, 1977). 
190 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 3B–2. Contrast-enhanced Landsat Thematic Mapper natural color image of the Badakhshan area of 

interest. Geologic units and faults from (Abdullah and Chmyriov, 1977).

Most faults in the regions are southwest to northeast trending. The entire region is highly 

fractured. Fault traces and geologic boundaries could be improved significantly with the addition of 

information from the HyMap results. 

3B.3.3 Known Mineralization

Figure 3B–5 shows the locations where mineralization with a potential for mineral resource 

development may exist (Peters and others, 2007). A number of different types of mineral deposits, 

particularly metamorphic gold vein, gold-copper skarn, iron skarn, and polymetallic vein deposits are 

present within the Badakhshan AOI. Of these known mineral deposits, only 18 occur within the 

boundaries of the HyMap data. The mineralogical characteristics of the mineralized locations are 

summarized in table 3B–1. 

Ragh and Baharak subareas in the Badakhshan AOI are beyond the coverage of the HyMap data. 

These areas are thought to have significant potential for gold. Future remote sensing and geochemical 

and geophysical studies of these remote areas are expected to improve understanding of these areas and 

their economic potential. 

Gold occurrences in the Fayz Abad District subarea have characteristics similar to pluton-related 

gold deposits rather than to regional metamorphic deposits. The Furmorah gold occurrence lies proximal 
Chapter 3B. Hyperspectral Mapping Analysis for the Badakhshan Area of Interest 191

to a number of iron skarn occurrences, such as the Syakh Jar, Kalawock, and Dozah-Dara iron skarns, 

and consists of an 80-km2-size mineralized area along the outer contact between Oligocene granite that 

intrudes Upper Permian to Upper Triassic sandstone and limestone. Mineralized zones consist of 

garnetiferous and garnet-magnetite skarn. Away from the skarn areas, mineralization consists of 

quartz-sulfide. 

Figure 3B–3. Elevations and topography of the Badakhshan area of interest. 
192 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Table 3B–1. Sites of known sites of mineralization in the Badakhshan area of interest (Peters and others, 2007).

Name Deposit type Alteration Mineralogy Gangue

Talbuzanak pegmatite _ Spodumene; cleavelandite; Biotite; microcline; quartz

beryl; columbite; tantalite; 

pollucite

Unnamed skarn Cu Skarn alteration of tremolite- No data Tremolite

actinolite facies

Furmarah skarn Fe Hornfels Magnetite No data

Syakh Jar skarn Fe Hornfels Magnetite; hematite No data

Unnamed skarn Fe Skarn alteration of magnetite Magnetite No data

facies

Unnamed skarn Fe Skarn alteration of magnetite Magnetite Garnet

facies; Skarn alteration of 

garnet-magnetite facies

Figure 3B–4. Geologic map of the Badakhshan area of interest from 1:500,000-scale geologic map of 

Afghanistan (Abdullah and Chmyriov, 1977). 

3B.4 Mineral Maps of the Badakhshan Area of Interest

Analysis of the HyMap imaging spectrometer data of the Badakhshan AOI using spectroscopic 

methods resulted in the identification of a wide variety of minerals exposed at the surface. Although the 

occurrence of certain minerals may suggest that mineralization processes may have once operated in the 
Chapter 3B. Hyperspectral Mapping Analysis for the Badakhshan Area of Interest 193

area, many of the minerals that were identified are also common rock-forming minerals or minerals that 

can be derived from the weathering of a wide variety of rock types. Consequently, knowledge about the 

the distribution patterns of the identified minerals and the geologic context in which they occur are 

extremely important in understanding the causes of mapped mineral occurrences and evaluating the 

possible potential for related mineral deposits. The presence of abundant vegetation that has masked the 

surficial minerals in significant parts of the area have reduced the utility of the hyperspectral data for 

overall site characterization in a few areas in the Badakhshan AOI.

Figures 3B–6 and 3B–7 depict the distribution of the carbonates, phyllosilicates, sulphates, 

altered minerals, and other materials (32 possible classes) and the iron -bearing minerals (28 possible 

classes) for the entire Badakhshan AOI. 

Figure 3B–5. Sites of known mineralization by deposit type (Peters and others, 2007) on the geologic map of the 

Badakhshan area of interest from 1:500,000-scale geologic map of Afghanistan (Abdullah and Chmyriov, 1977).

Figure 3B–6 shows the distribution of the carbonates, phyllosilicates, sulphates, altered minerals, 

and other materials. The carbonate classes, muscovite, illite, and vegetation dominate this region. 

Spatially consistent patterns of the dolomite classes, montmorillonite, and the serpentine classes occur 

throughout the AOI. Vegetation is mapped throughout the AOI, with the largest concentrations mapping 

in the eastern and south-central areas. Extensive vegetation cover in this region prevents one from seeing 

the underlying mineralogy in geologically important areas of the AOI.

The calcite and calcite + muscovite/illite classes generally map in the central region of the AOI 

running north-south. Smaller coherent groupings of these classes do occur throughout the entire AOI 
194 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

and map in most of the geologic units of the region. Calcite + montmorillonite mostly maps in the 

southwestern corner of the HyMap data but also occurs throughout the AOI as well. Iron carbonate 

groupings occur in or near a stream drainage running northwest to southeast in the lower half of the 

AOI. Outside of the drainage system, iron carbonate maps in a linear feature the runs east-west near 

37°13'58"N, 70°31'44"E and should be looked at in more detail because of its close proximity to nearby 

faults and an intrusive body. 

Muscovite and illite map in large contiguous areas within Mississippian and Oligocene intrusive 

rocks and in Early Proterozoic stratified units. In the central fault system, muscovite and illite appear 

either to be bounded by or to occur on fault lines. This suggests the HyMap data could help improve 

data accuracy on these maps. 

Figure 3B–6. Map of carbonates, phyllosilicates, sulfates, altered minerals, and other materials derived from 

HyMap data in the Badakhshan area of interest. 

The dolomite, dolomite + montmorillonite/calcite, serpentine and serpentine or calcite + 

dolomite classes occur in scattered patterns over much of the AOI but many smaller coherent groupings 

do occur. These smaller groupings of the dolomite classes group best along fault lines in the central 

region of the AOI. Dolomites map within units of Early Proterozoic, Cambrian, Silurian-Devonian, Late 

Devonian-Mississippian, and Mississippian age rocks and are consistent with minerals found in these 

units. 

The largest occurrences of serpentine minerals map along the contact boundary of Early Triassic 

intrusive rocks or along faults that are in close proximity to Early Triassic intrusive rocks. It should be 
Chapter 3B. Hyperspectral Mapping Analysis for the Badakhshan Area of Interest 195

noted that upon further analysis of the spectral data that mapped as serpentines, a 2.38-μm feature is 

usually found to be present in HyMap spectra. This 2.38-μm band is usually very weak in hyperspectral 

data of most serpentines but is much stronger in amphibole minerals. The 2.32-μm feature of serpentine 

in this region also exhibits a slight shoulderness around 2.30 μm, which would also be consistent with 

amphiboles. Additional work to define the composition of rocks in these areas is warranted in 

conjunction with further analysis of the imaging spectrometer data. 

Chlorite or epidote occur in spatially consistent patterns in large areas in the south-central 

regions and smaller areas in the central and north-central regions. The southern occurrence of chlorite or 

epidote maps across different age geologic units. The central detection of chlorite or epidote mainly 

occurs within Early Triassic intrusive rocks. Other epidote or chlorite detections in this area may suggest 

that this intrusive body is larger than on the current Russian map. Chlorite or epidote in the north-central 

region map within Silurian-Devonian age rocks but tend to occur along fault lines. In several places the 

chlorite or epidote map as a series of offset blocks. This suggests that the fault lines need to be extended 

in many areas. 

Figure 3B–7. Map of iron-bearing minerals and other materials derived from HyMap data in the Badakhshan area 

of interest. 

Montmorillonite occurs as individual pixels or small clusters throughout the AOI with the largest 

coherent grouping mapping near the southern border in the south-central region of the AOI. This area is

clearly visible with the blue-grey colors in the TM image (see fig. 3B–2). 
196 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Tremolite or talc did map in small groupings in several areas, which is consistent with the 

mineralogy of the area. The addition of a more diverse range of amphibole entries into the spectral 

library and ground sampling could improve mapping within this classification. 

The iron-bearing materials map is shown in figure 3B–6. A large portion of the data mapped into 

the Not Classified classification. This shows that the rocks in this AOI lack minerals that contain 

significant absorption features in the 1 μm region of the electromagnetic spectrum. The image clearly 

demonstrates the extensive vegetation coverage in the Badakhshan AOI. The vegetation covers surface 

exposures and can limit the usefulness of the HyMap data and analysis in this region. Of the classified 

pixels in this region (other than the Not Classified or Non-data Pixel classifications), vegetation 

accounts for 60 percent of the identifications.

 

Figure 3B–8. Contrast-enhanced Landsat Thematic Mapper natural color image of the Fayz Abad District 

subarea. Geologic units and faults from Abdullah and Chmyriov, 1977.

The south-central and south-west regions of the AOI mapped large areas of Fe2+ Fe3+ Type 2, 

epidote, Fe3+ Type 1 and Fe2+ Type 1. The Fe2+ Fe3+ Type 2, epidote and Fe2+ Type 1 classes map 

together throughout this area and generally occur in older Proterozoic rocks. A large cluster of 

Fe2+ Fe3+ Type 2 minerals also occur near the northern limit of the dataset at some of the highest 

elevation in the region. A large cluster of Fe3+, Type 1 pixels occur within the river basin in the 

southwest corner of the AOI. Concentrations of goethite and Fe-hydroxide are limited to a small area on 
Chapter 3B. Hyperspectral Mapping Analysis for the Badakhshan Area of Interest 197

the border of the AOI in the southwest corner and small occurrences along fault lines in the northern 

region of the HyMap data. Early Triassic and Oligocene intrusive rocks are noted as lacking any 

significant detections of minerals that are found in the iron-bearing classifications. 

It is possible that the spectral library does not have a representative entry for the mineral or 

mineral mixture of rocks in these areas. There are several areas where reflectance levels in the longer 

wavelengths (2 to 2.5 μm region) of rocks are low (10 percent to 20 percent at 2.272 μm) compared to 

surrounding areas (20 percent to 45 percent at 2.272 μm). The addition of a 2.38 μm band in certain 

spectra is also intriguing. Understanding of the rocks in these areas would benefit from additional field 

work. 

Figure 3B–9. Elevations and topography of the Fayz Abad District subarea.

3B.4.1 Fayz Abad District Subarea

Detailed maps of the Fayz Abad District subarea are presented in figures 3B–8 through 3B–13. 

The Fayz Abad District subarea covers almost 50 percent of the total HyMap coverage for the area and 

most of the significant details of this area have already been discussed above. Figures 3B–8 through 3B–

11 show the contrast-enhanced natural color Landsat TM image, elevation data for this region, geologic 

map and the geologic map with known mineral occurrences. The elevation in the Fayz Abad District 

subarea ranges from 1,112 to 3,696 m. Stratified rocks in the Fayz Abad District subarea range in age 

from Early Proterozoic to Middle Quaternary. Intrusive rocks of Mississippi, Early Triassic and 

Oligocene age occur within the subarea (Abdullah and Chmyriov, 1977). The Proterozoic intrusive 
198 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

rocks occur extensively in the central and western region of the subarea. Paleozoic, Mesozoic and 

Cenozoic rocks occur along the eastern border of the subarea with small sections along the northern 

border. A large Early Triassic intrusive body occurs in the northwestern region with smaller intrusions to 

the south. Smaller intrusions of Mississippian and Oligocene rocks occur in the northwest and southeast 

corner of the subarea. The subarea is heavily faulted with north-south trending faults.

Figure 3B–10. Geologic map of the Fayz Abad District subarea from 1:500,000-scale geologic map of 

Afghanistan (Abdullah and Chmyriov, 1977).

Figure 3B–12 shows the distribution of carbonates, phyllosilicates, sulphates, altered minerals, 

and other materials within the Fayz Abad District subarea. Vegetation and calcite class minerals 

dominate most of the region and can be found in most rock units. Calcite and calcite + muscovite/illite 

predominantly map in the central and western region of the subarea. The calcite + montmorillonite class 

maps in spatially consistent patterns in the western third of the subarea with calcite, calcite + 

muscovite/illite, muscovite and illite dispersed throughout. Chlorite and epidote concentrations occur 

along the river basin in the south-central region, within Early Triassic intrusive rocks in the northwest 

region, and along fault lines in the northeast region of the subarea. Muscovite with smaller amounts of 

illite map throughout the subarea. In the northern regions they appear to map in bedded formations 

running mostly north-south. Muscovite, illite, and the main detections of kaolinite + 

muscovite/clay/calcite are associated with Oligocene intrusive rocks in the southeast region. The 

dolomite, dolomite + montmorillonite/calcite, serpentine, and serpentine or calcite + dolomite classes 
Chapter 3B. Hyperspectral Mapping Analysis for the Badakhshan Area of Interest 199

seem to map along intrusive body contacts or on fault lines near intrusive rocks. Iron carbonate maps 

along the river basin to the south and in the west-central region.

Figure 3B–11. Sites of known mineralization by deposit type (Peters and others, 2007) on the geologic map of 

the Fayz Abad District subarea from 1:500,000-scale geologic map of Afghanistan (Abdullah and Chmyriov, 1977).

Figure 3B–13 shows the mineral distribution of iron-bearing minerals for the Fayz Abad District 

subarea. Vegetation covers most of the central and eastern regions of the subarea. Fe2+ Fe3+ Type 2, 

epidote, Fe3+ Type 1, and Fe2+ Type 1 concentrations occur throughout the central and western region in 

Early Proterozoic (Early Part) stratified formations. The intrusive rock units do not map significant 

amounts of iron-bearing minerals. Small linear groupings of the goethite class minerals occur in the 

northeastern region of the subarea and may be related to fault lines.
200 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

 

Figure 3B–12. Map of carbonates, phyllosilicates, sulfates, altered minerals, and other materials derived from 

HyMap data in the Fayz Abad District subarea.

3B.5 Summary 

The HyMap data for the Badakhshan AOI shows several locations based on the presence of 

specific minerals or groups of minerals that suggest the need for additional field sampling and 

geochemical characterization. The northern and eastern limits of the HyMap dataset result in only partial 

coverage within the Badakhshan AOI. Only the Fayz Abad District subarea was covered with HyMap 

data in this region. 

While vegetation, calcite class minerals, muscovite, and illite map extensively throughout the 

AOI, the proximity of the dolomite class minerals, serpentine class minerals, and iron carbonates to 

intrusive contacts or fault lines warrants further investigation. These detections would also benefit from 

additional field sampling, as weaker features in the spectra indicate that other minerals are present 

within these rock units. The addition of spectra of rock types of this area that aren’t part of our current 

spectral library and the acquisition of data from a local ground calibration site could improve the 

accuracy of the maps within this region. 
Chapter 3B. Hyperspectral Mapping Analysis for the Badakhshan Area of Interest 201

Figure 3B–13. Map of iron-bearing minerals and other materials derived from HyMap data in the Fayz Abad 

District subarea.

3B.6 References Cited

Abdullah, Sh., and Chmyriov, V.M., 1977, Geological map of Afghanistan: Kabul, Afghanistan, 

Ministry of Mining and Industry of Democratic Republic of Afghanistan, scale 1:500,000. 

Abdullah, Sh., Chmyriov, V.M., Stazhilo-Alekseev, K.F., Dronov, V.I., Gannan, P.J., Rossovskiy, L.N., 

Kafarskiy, A.Kh., and Malyarov, E.P., 1977, Mineral resources of Afghanistan (2d ed.): Kabul, 

Afghanistan, Republic of Afghanistan Geological and Mineral Survey, 419 p. 

Cocks, T., Jenssen, R., Stewart, A., Wilson, I., and Shields, T., 1998, The HyMap airborne hyperspectral 

sensor—The system, calibration and performance, in Schaepman, M., Schlapfer, D., and Itten, K.I., 

eds., Proceedings of the 1st EARSeL Workshop on Imaging Spectroscopy, 6–8 October 1998, Zurich: 

Paris, European Association of Remote Sensing Laboratories, p. 37–43. 

Davis, P.A., 2007, Landsat ETM+ false-color image mosaics of Afghanistan: U.S. Geological Survey 

Open-File Report 2007–1029, 22 p. (Also available at http://pubs.usgs.gov/of/2007/1029/

Hoefen, T.M., Kokaly, R.F., and King, T.V.V., 2010, Calibration of HyMap data covering the country 

of Afghanistan, in Proceedings of the 15th Australasian Remote Sensing and Photogrammetry 

Conference, Alice Springs, Australia, September 12–17, 2010, p. 409, available at 

.) 

http://dl.dropbox.com/u/81114/15ARSPC-Proceedings.zip/.
202 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

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