Chapter 7B. Analysis of Imaging Spectrometer Data for the 

Haji-Gak Area of Interest

By K. Eric Livo and Stuart A. Giles

Abstract

Imaging spectrometer data of the Haji-Gak area of interest (AOI) in the central-northeastern part 

of Afghanistan were analyzed using spectrum matching techniques to identify the distribution of 

selected materials at the surface. Characteristic absorption features (absorption bands) in the HyMap 

data were compared to a library of spectral standards. Wallrock mineralogy was detected in the HyMap 

data that is permissive for hosting iron ores and barite mineralization.

A sequence of Proterozoic and Paleozoic age rocks hosts known iron deposits. Spectrally 

mapped minerals within the host rock associated with this iron mineralization may be traced from the 

Haji-Gak deposits on the southwest extending northeastward through the AOI. Barite is associated with 

a group of spectrally mapped minerals within Ordovician age rocks in the northeastern part of the AOI.

7B.1 Introduction

Previous U.S. Geological Survey (USGS) analyses of existing geologic data of Afghanistan 

revealed numerous areas with indications of potential mineral resources of various types (Peters and 

others, 2007). From these areas of interest, several were selected for follow-on studies using modern 

hyperspectral remote sensing data to characterize surface materials. One of those areas is the Haji-Gak 

area in central-northeastern Afghanistan.

The Haji-Gak area of interest (AOI) is in the Bamyan and Wardak Provinces and extends 

northeastward into the Parwan Province (fig. 7B–1). The AOI contains Middle Proterozoic sedimentary 

rocks that host the Haji-Gak iron-oxide deposit and have the potential for iron, barite, lead-zinc, 

limestone, and sandstone deposits (Abdullah and others, 1977; Peters and others, 2007).

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 those analyses and identifies numerous sites within the 

Haji-Gak area that merit further investigation, especially detailed geological mapping and geochemical 

studies.

7B.1.1 Hyperspectral Data Collection and Processing

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

and 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 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 

only be used to characterize the upper surface materials and not subsurface composition or structure.

However, subsurface processes can be indicated by the distribution of surface materials that can be 

detected using imaging spectroscopy data.
500 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–1. The Haji-Gak area of interest is located about 100 kilometers west of Kabul in Bamyan, Wardak, 

and Parwan Provinces.

7B.1.2 Collection of Imaging Spectrometer Data

The HyMap imaging spectrometer (Cocks and others, 1998) was flown over 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 approximately 50,000 ft. 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 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 UTM projection (Davis, 2007). 

7B.1.3 Calibration Process

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 (Clark and 
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 501

others, 2003a) 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, Calif.). ACORN was run multiple times for each flight line, using average 

elevations in 100-m increments, covering the range of minimum to maximum elevation within the flight 

line. A single atmospherically corrected image was assembled from these elevation-incremented 

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. Five ground-calibration spectra were 

collected in Afghanistan: field spectra at 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. At each site, the 

average field spectrum of the ground target was used to calculate an empirical correction factor using the 

pixels of atmospherically corrected HyMap data in the flight lines that passed over the site. 

Subsequently, each of the HyMap flight lines was ground-calibrated using the empirical correction from 

the closest calibration site. 

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 groundcalibration sites. 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, cross-cutting calibration 

flight lines over the ground-calibration areas were acquired (Kokaly and others, 2008) and used to refine 

the reflectance calculation for standard data lines. A multiplier correction for standard data lines, 

typically oriented as north-south flight lines, was derived using the pixels of overlap with the wellcalibrated cross-cutting lines, 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, reduced residual atmospheric contamination in the imaging spectrometer data that may 

have been present after the ground-calibration step. 

7B.1.4 Materials Maps and Presentation

After undergoing the above calibration process, the georeferenced and calibrated reflectance data 

were processed. The reflectance spectrum of each pixel of HyMap data was compared to the spectral 

features of reference entries in a spectral library of minerals, vegetation, water, and other materials 

(King, Kokaly, and others, 2011; Kokaly and others, 2011). The best spectral matches were determined 

for each pixel, and the results were clustered into classes of materials discussed below.

HyMap reflectance data were processed using the MICA (Material Identification and 

Characterization Algorithm), a module of the U.S. Geological Survey PRISM (Processing Routines in 

Interactive Data Language (IDL) for Spectroscopic Measurements) 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 MICA spectral comparison 

technique is partly derived from the Tetracorder spectral identification system (Clark and others, 2003b). 

The HyMap data were compared to 97 reference spectra of well-characterized mineral and material 

standards. The resulting maps of material distribution, resampled to 23 × 23 meter square pixel grid, 

were mosaicked to create thematic maps of surface mineral occurrences over the full dataset covering 

Afghanistan. 

MICA 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 the visible and near-infrared wavelength 
502 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

region, producing a 1-μm map of iron-bearing minerals and other materials (King, Kokaly, and others, 

2011), and again using the subset of minerals with absorption features in the shortwave infrared, 

producing a 2-μm map of carbonates, phyllosilicates, sulfates, altered minerals, and other materials. 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 mineral classes. The iron-bearing minerals map has 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 compositions but similar spectral features are less easily discriminated; thus, some identified 

classes consist of several minerals with similar spectra, such as the chlorite or epidote class. When 

comparisons with reference spectra provided no viable match, a designation of “not classified” was 

assigned to a pixel. 

7B.2 Geologic Setting of the Haji-Gak Area of Interest

The Haji-Gak area of interest is located in the Bamyan, Wardak, and Parwan Provinces of 

Afghanistan (fig. 7B–1). A large anomalous crustal block within the central tectonized zone, with deep 

valleys on all four sides, hosts the AOI. Elevations range from 1,900 to 4,962 m (fig.7B–2). The 

Haji-Gak area of interest is approximately 2,079.29 km2 . Within this AOI are three subareas: Haji-Gak 

Prospect (180 km2

), Northeast Haji-Gak (381 km2), and Farenjal (557 km2) subareas (see fig. 7B–5). 

Numerous faults and fractures of different orientations and extent occur in the AOI (fig. 7B–3). Within 

the Haji-Gak AOI, the most prominent faults strike northeast to southwest, with younger faults trending 

north-south and northwest-southeast, which juxtaposed Middle Proterozoic, Late Proterozoic, and late 

Paleozoic age rocks during the Cretaceous (Kusov and others, 1965). 

7B.2.1 Lithology and Structure

The Haji-Gak area of interest contains metavolcanic and metasedimentary rocks of Middle to 

Late Proterozoic age, as well as Paleozoic and Tertiary age rocks (fig. 7B–4). The Middle Proterozoic 

Jawkol Formation, consisting of limestones, dolomites, schists, and quartzites, has been metamorphosed 

to amphibolite grade and is the oldest part of the stratigraphic succession. These rocks outcrop in the 

northwestern part of the Haji-Gak AOI. Late Proterozoic Kab Formation and the overlying Awband 

Formation form the Qala Series of metavolcanic and metasedimentary rocks that are interpreted as being 

deposited within a marine basin (Kusov and others, 1965). According to Kusov and others (1965), the 

Kab Formation is composed of sericite schists, phyllite, volcanic rocks, and marble. The Awband 

Formation contains quartz-sericite and quartz-chlorite-sericite schists, along with cherts and marbles. 

The Awband hosts most of the iron deposits that are postulated as being sedimentary exhalative 

iron-rich fluids that formed lenses on the sea floor during times of increased volcanic activity (Peters 

and others, 2007). Above the Qala Series is the Late Proterozoic Green Schist Formation, which 

comprise chlorite schists and quartz-sericite schists that host lesser iron mineralization. Southeast of the 

Proterozoic rocks, Devonian to Mississippian limestones, conglomerates, sandstones, and pelagic schists 

and Permian rocks are in fault contact. The northeast region of the AOI contains Mississippian, 

Ordovician, and Silurian to Devonian rocks in fault contact with the northeastern extent of the 

Proterozoic rocks (Abdullah and Chymriov, 1977; Doebrich and others, 2006). 

During the Cretaceous, displacement along the Herat fault zone has juxtaposed Middle 

Proterozoic, Late Proterozoic, and upper Paleozoic rocks, forming the northeast-trending Haji-Gak 

anticline that hosts the iron deposits on the exposed southeast limb within the Late Proterozoic units 

(Kusov and others, 1965). The predominant strike at the Haji-Gak deposit is to the northeast with a 

regional dip of 50° to the southeast. The Haji-Gak iron deposits occur in the southwest region 
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 503

(Haji-Gak Prospect subarea, fig. 7B–5) and similar mineralization to the known iron deposits is exposed 

to the northeast along a high ridge (Northeast Haji-Gak subarea, fig. 7B–5; Doebrich and others, 2006; 

as mapped using HyMap data), and is fault truncated (pinched out) on the northeast end (Farenjal 

subarea: fig. 7B–5; Doebrich and others, 2006). 

Figure 7B–2. Shaded-relief map showing elevations in the Haji-Gak area of interest (AOI). The darker brown 

tones indicate the higher elevations, and the lower elevations are represented by the green tones. The AOI is 

drained by several rivers, principally the Gorband River and its southern tributary.

7B.2.2 Known Mineralization

Table 7B–1. Deposit name, deposit type, mineralogy, 

Haji-Gak area of interest.

[unk, unknown]

and alteration of the known sites of mineralization in the 

Name Deposit type Mineralogy Gangue Alteration

Hajigak unk stone No data No data _

Haji-Gak Sandstone unk sandstone No data No data _

Haji-Gak Silica silica –

Haji-Gak Barite vein barite Barite Quartz; sericite Baritization

Haji-Gak Limestone limestone

Haji-Gak Iron unk Fe Pyrite; magnetite; Carbonate; siderite; quartz; barite Carbonatization; 

hydrogoethite; silicification; 

martite; hematite sericitization; 

chloritization

Chapkul vein barite Barite Quartz; sericite Baritization
504 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Name Deposit type Mineralogy Gangue Alteration

Harzar unk Fe Hematite; No data _

magnetite; 

martite

vein barite Barite Quartz; sericite Baritization

Rokul

Khaish unk Fe Hematite; Sericite; chlorite; carbonate _

magnetite

Sausang unk Fe Hematite; Quartz; chlorite _

magnetite

Chuy unk Fe Hematite; Quartz; chlorite _

magnetite

Zarak vein barite Barite No data Baritization

Unnamed unk W Pyrite; galena; No data _

scheelite; 

chalcopyrite; 

gold native

Zerak unk Fe Hematite; Quartz; dolomite Dolomitization; 

magnetite silicification

Unnamed unk Fe Hematite; Barite _

magnetite; 

galena

Surkh-i-Parso unclassified Chalcopyrite; Quartz Marmorization; 

uranite silicification

Dara-i-Neel unk Fe Martite No data _

Tanghi-Loli unk Ba Barite No data _

Unnamed unk Ba Barite No data Baritization

Farenjal Talc ultramafic-hosted talc Talc; serpentine No data

Talc alteration; 

overprinting 

serpentinization

Farenjal Manganese unk Mn No data _

Pyrolusite; 

psilomelane; 

hematite

Farenjal Barite bedded barite Barite; witherite; Quartz; calcite Baritization

chalcopyrite; 

pyrite; galena

Northern Farenjal vein barite No data Baritization

Barite

Unnamed unk Ba Barite; galena No data Baritization

Unnamed unk Ba Barite No data Baritization

7B.3 Mineral Maps of the Haji-Gak Area of Interest

Analysis of the HyMap data of the Haji-Gak AOI using spectral mapping techniques resulted in 

the identification of a variety of surficial minerals. These minerals have been identified on the presence 

and wavelength position of absorption features in the 0.45–2.48 μm wavelength region. Two general 

categories of minerals are recognized: (1) iron-bearing minerals that have characteristic spectral 

absorption features that occur at wavelengths near 1 μm, and (2) a wide variety of minerals, including 

carbonates, mica and clay minerals, and sulfates that have diagnostic spectral absorptions near 2 μm.

Although the occurrence of certain minerals may suggest mineralization processes may have operated in 

the area, many of the minerals identified and mapped are also common rock-forming minerals or 

minerals that can be derived from the weathering of a variety of rock types. Consequently, the 

distribution patterns of the identified minerals and the geologic content where they occur are extremely 

important in understanding the causes of the mapped mineral occurrences and assessing the possible 

potential for related mineral deposits.
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 505

Two general types of hyperspectral maps are included: (1) complete AOI maps showing the 

entire mapped suite of minerals that have absorption in 1-μm and 2-μm wavelengths, and (2) topical 

maps that are subsets of the mineral classes. The topical maps, which depict selected groups of minerals 

that are mineralogically related or commonly occur together, are presented to show subtleties in the 

mineral distribution. A set of maps has been produced for the full Haji-Gak AOI and each of the 

subareas. It should be noted that geographic registration between various datasets is not always possible, 

because of differences in collection methods and resolution. A companion report and geodatabase of 

potential mineral resource anomalies (areas of a potential economic mineral resource occurrence) that

were not previously known or where the HyMap data has expanded our knowledge of the region can be 

found in King, Johnson, and others (2011).

Figure 7B–3. Numerous faults and fractures of different orientations and extent occur within the Haji-Gak area of 

interest. The fault traces (Doebrich and others, 2006) are placed on a Landsat Thematic Mapper image (Davis, 

2007).
506 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–4. The geologic map of the Haji-Gak area of interest (AOI) is from the 1:500,000-scale geologic map of 

Afghanistan (Dronov and others, 1972). A series of intrusive rocks are exposed in the northern part of the AOI along 

the secondary fault traces and also in the southwest adjacent to a major secondary fault.

7B.3.1 Haji-Gak Area of Interest

Figures 7B–6 and 7B–7 shows the distribution of carbonates, phyllosilicates, sulfates, altered 

minerals, and other materials (30 possible classes) and the Fe-bearing minerals (27 possible classes), 

respectively, for the entire Haji-Gak AOI. HyMap data are also a powerful tool to use in the 

identification and mapping of faults and fractures (see fig. 7B–9); note the correlation between mapped 

minerals and fault traces. Because of the large number of mineral classes represented and the subtleties 

of the distribution patterns in these maps, it is more instructive to display these results as a series of 

topical images depicting a group of minerals that are commonly related or occur together in special 

geologic environments (figs. 7B–8 to 7B–12). Figure 7B–8 shows the distribution of carbonate minerals 

in the AOI, whereas figure 7B–9 shows where the clays and micas were mapped. The distribution of 

iron-oxide and iron-hydroxide minerals are displayed in figure 7B–10. Secondary minerals are shown in 

figure 7B–11, and minerals commonly found in hydrothermally altered rocks are mapped in figure 7B–12.

Spectrally mapped minerals (1- and 2-μm wavelengths; figs. 7B–7 and 7B–6) correlate with the 

field-mapped lithologies of the Haji-Gak Proterozoic stratigraphic succession that form the diagenetic 

hanging and footwalls of the sedex iron-oxide deposits (most clearly seen in the mineral maps of the 

Haji-Gak iron deposit in the Haji-Gak Prospect subarea; fig. 7B–5) located in the southwestern part of 

the AOI. Upward through the sequence (trending southeast, perpendicular to strike in the image; see 
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 507

fig. 7B–6), scattered carbonate pixels are associated with regions containing the Middle Proterozoic 

Jawkol Formation (limestone and dolomite). Ferrous and ferric (goethite) iron (see fig. 7B–7), 

muscovite (sericite or illite), and possibly kaolinite pixels trend within regions containing the Late 

Proterozoic Qala Series (Kab and Awband Formations; see fig. 7B–6) that hosts the majority of iron 

deposits (sericite, quartz-sericite, and quartz-chlorite schists, phyllite, volcanic rocks, and minor chert 

and marble; Kusov and others, 1965; Renaud and others, chap. 7A, this volume). Stratigraphically 

higher (to the southeast), the Green Schist Formation (chlorite schists and quartz-sericite schists) also 

hosts iron deposits, though to a lesser extent, and is mapped using epidote/chlorite and serpentine 

mineral pixels (see fig. 7B–6 and Haji-Gak Prospect subarea section). Paleozoic limestones are located 

to the southeast and were identified by the presence of an abundant calcite zone (lat 34°45'N., long 

68°12'W.) that trends along strike to the northeast. This sequence of rocks is spectrally mapped trending 

northeast through the length of the bottom half of the AOI. It forms the southeast limb of the Haji-Gak 

anticline, along the ridgeline of the host block. 

Figure 7B–5. This map shows the location of known mineral occurrences in the Haji-Gak area of interest (AOI).

The map consists of four data layers: shaded-relief base map, transparency of the geologic map (Dronov and 

others, 1972), fault traces (Peters and others, 2007), and known mineral occurrences (Abdullah and others, 1977). 

The map shows the overall AOI and three subareas:Haji-Gak Prospect, Northeast Haji-Gak, and Farenjal

subareas. 
508 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

7B.3.1.1 Carbonate Minerals

The calcite and calcite + muscovite/illite groups follow the southern edge of the major trend of 

iron-oxide deposits that occur at the western end of the image and projects eastward throughout the 

mapped area (fig. 7B–8). These groups potentially define the Paleozoic limestones above the iron-oxide 

zone that were deposited after the iron was precipitated on the sea floor. Additional calcite was mapped 

to the far northeast and north, trending within or near Paleozoic rocks, especially within the Uluk and 

Kuberghandin horizons (fig. 7B–5).

7B.3.1.2 Clays and Micas

The phyllosilicates are the most dominant group of minerals mapped in the AOI (fig. 7B–9). 

Muscovite (sericite) and illite group minerals are widespread. Chlorite or epidote group minerals, when 

present, occur primarily in the Proterozoic greenstones (Green Schist Formation) in the western part of 

the AOI and in Ordovician rocks in the northeastern part of the AOI. Chlorite or epidote are anomalous 

just northwest of the Haji-Gak deposits, within the Proterozoic sequence. 

Figure 7B–6. Distribution of clays, carbonates, phyllosilicates, sulfates, altered minerals, and other materials 

detected in the HyMap data for the entire Haji-Gak area of interest. The identification of the specific minerals is 

based on the presence of characteristic absorption features resulting from vibrational processes in the mineral. The 

map area was analyzed to detect the presence of 32 possible specific minerals or groups of minerals.
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 509

The kaolinite group of minerals primarily occurs in the far northeast, cutting across 

Mississippian to Proterozoic age rocks and tend to be located along or near the major drainages. Minor 

amounts of kaolinite group minerals occur as spatially discrete regions along the iron-oxide trend near 

the middle of the AOI. 

7B.3.1.3 Iron Oxides and Iron Hydroxides

Figure 7B–10 shows the iron-bearing minerals in the Haji-Gak AOI. These iron-bearing minerals 

can roughly be grouped within three trends. The most important is a discontinuous goethite trend within 

the Haji-Gak iron-oxide deposits that extends eastward along the projected iron trend with muscovite 

(sericite; see fig. 7B–9) and ferrous iron, though the ferric iron (goethite) becomes more abundant and 

quickly broadens in the central region (described in detail within the subareas). Another trend is within 

the eastern end of the AOI, overlaying and extending past the kaolinite zone, cutting across lithologic 

boundaries. The third trend is a hematite-rich zone within Tertiary rocks at the northwestern corner of 

the AOL. Minor hematite also occurs at the easternmost part of the AOI. 

Figure 7B–7. This image shows the iron-bearing minerals and other materials in the Haji-Gak area of interest

detected in the HyMap data. 

7B.3.1.4 Common Secondary Minerals

The occurrence and distribution of common secondary minerals for the AOI are shown in figure 

7B–11. This map shows information taken from both the 1-μm and 2-μm datasets. The chlorite or 
510 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

epidote group minerals, as described within the Clays and Mica section standout within the Proterozoic 

rocks near the Haji-Gak iron deposit. A discontinuous trend of chlorite or epidote group minerals also 

follows the northern contact of Proterozoic-Paleozoic rocks (between the village of Shibar and the Darai-Neel mineral occurrence). Serpentine-bearing rocks are associated with carbonate-bearing units, 

especially in the northeast part of the AOI. Importantly, small, local serpentine-rich rocks are associated 

with the Haji-Gak iron deposits (see fig. 7B–11). A strong zone of serpentine-bearing rock (fig 7B–11) 

occurs near the Sausang mineral occurrence within a region of spatially coherent calcite.

7B.3.1.5 Common Alteration Minerals

Most of the minerals in this group are commonly present in hydrothermally altered rocks 

associated with epithermal processes. Consequently, where they occur in distinct clusters is of great 

interest in terms of potential mineral deposits. However, the only association of chlorite or epidote group 

minerals and kaolinite (fig. 7B–9) with Oligocene intrusive rocks occurs on the southwestern edge of the 

area (fig 7B–12). All other occurrences are as described within the Clays and Micas section above.

Figure 7B–8. Distribution of carbonate-bearing minerals detected by the HyMap data in the Haji-Gak area of 

interest detected in the HyMap data. 

7B.3.2 Haji-Gak Prospect Subarea

The known mineral occurrence map (semi-transparent geologic map overlain on a shaded-relief

image) shows the position of reported mineral occurrences in the Haji-Gak Prospect subarea (fig. 7B–13), 
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 511

including the Haji-Gak iron deposit, with associated barite, limestone, silica, sandstone, Harzar iron, and 

Chapkul and Rokul vein-barite occurrences. Iron-oxide deposits at Haji-Gak Prospect subarea make up 

the most important iron resource presently known in Afghanistan. The structurally controlled 

mineralization is estimated by Russian scientists to have a mining reserve of 85 million metric tons 

(Abdullah and others, 1977; Peters and others, 2007). Primary ore consists of magnetite and pyrite with 

minor chalcopyrite. Oxidized ores are composed of three hematitic types, whereas altered-rock 

mineralization from the ore-forming event includes sericitization, silicification, and carbonization. The 

Harzar iron occurrence is hosted by greenschist containing 300-m-thick hematitic lenses grading to as 

much as about 63-weight-percent iron. 

The topography in the area ranges from 2,874 to 4,324 m (fig. 7B–14). The Haji-Gak Prospect 

subarea deposits and mineralization trends northeast along the topographic ridge on the southeast-facing 

slope. 

Figure 7B–9. Distribution of clays and micas identified in the HyMap data for the Haji-Gak area of interest

detected in the HyMap data. 

The geologic map of the area (fig. 7B–15) shows stratified rocks ranging in age from Late 

Proterozoic to Early Permian, with Oligocene age intrusive rocks in fault contact with the Permian age 

rocks in the southwest corner of the AOI. The known mineral occurrences in the Haji-Gak Prospect 

subarea occur within the upper part of the Late Proterozoic rocks, near the contact with Paleozoic rocks 

(can be seen in detail within the Haji-Gak Prospect subarea on the Russian geologic map of Kusov and 

others, 1965; Renaud and others, chap. 7A, this volume). These iron deposits form large outcrops along 
512 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

the upper south-facing side of the main northeast-trending ridge of the subarea, as seen throughout the 

center of the Landsat Thematic Mapper (TM) image (fig. 7B–16). 

Mapped minerals (figs. 7B–17 and 18) correlate well within this subarea with lithology, 

especially when compared with the Renaud and others (chap. 7A, this volume) modified Russian 

geologic map (after Kusov and others, 1965). The Middle Proterozoic Jawkol Formation, containing 

limestone and dolomite, shows spatially distinct pixels of calcite. The iron-oxide-bearing Late 

Proterozoic Qala Series is composed of tuffites, argillaceous rocks, and minor chert and marble (Kusov 

and others, 1965); ferrous-and ferric-iron oxides, muscovite (sericite or illite), and lesser amounts of 

kaolinite are mapped using the HyMap data. Stratigraphically above the mineralized units, the Green 

Schist Formation consisting of chlorite schists and quartz-sericite schists have regions of mapped 

epidote/chlorite and serpentine (and mobilized iron occurrences). The overlying Paleozoic limestones 

are mapped with abundant calcite (linear, green calcite unit trending northeastward throughout the center 

of the subarea). 

Figure 7B–10.

Figure 7B–17 shows the distribution of Fe-bearing minerals and figure 7B–18 shows carbonate, 

sulfate, phyllosilicate and altered minerals. The map of Fe-bearing minerals (fig. 7B–17) displays the 

Haji-Gak Prospect iron-oxide deposit and nearby mineralization as a southwest to northeast linear trend 

through the center of the image. Ferrous- and ferric-iron oxide dominates the area with goethite on the 

Distribution of iron hydroxides and iron oxides mapped using the HyMap data for the Haji-Gak

area of interest detected in the HyMap data. 
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 513

fringes. Muscovite (sericite or illite) pixels shown in figure 7B–18 are highly correlated with the ironoxide pixels. 

The strike of the lithology is mapped by linear trending pixels of calcite, muscovite, 

chlorite/epidote, and calcite-bearing rock units (oldest to youngest, dipping to the southeast). There is an 

area of mapped minerals (iron oxide, chlorite/epidote, serpentine, and calcite) at the upper northwest 

corner of the image that is a separate region not associated with the main Haji-Gak mineralization.

Figure 7B–11. Occurrence and distribution of common secondary minerals detected in the HyMap data for the 

Haji-Gak area of interest detected in the HyMap data. 

7B.3.2.1 Haji-Gak Prospect Subarea: Carbonate Minerals 

Calcite-rich rocks are widespread over the entire subarea (fig.7B–19). The iron-mineralization 

trend in the center of the image contains a moderate abundance of carbonate minerals in a southwest to 

northeast zone that follows the iron-mineralization trend. A strong trend of calcite, parallel, but 

southeast (up dip) of the iron mineralization occurs within areas containing Paleozoic limestones (the 

strong, green linear trend through the center of the image). Pixels spectrally matched to calcite mixed 

with montmorillonite in the HyMap data may in actuality contain calcite mixed with clay and mica; the 

clay and mica is a mixture that could include sericite and possibly illite.
514 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

7B.3.2.2 Haji-Gak Prospect Subarea: Clays and Micas 

A southwest-northeast trend of muscovite (sericite or illite) minerals is present in the central part 

of the image along the iron-mineralization trend (fig. 7B–20). This pixel trend of pod-like occurrences 

spectrally matched to muscovite is along the topographic divide and shows variability in surficial 

abundance (along the ridge between Haji-Gak and Rokul mineral occurrences). South of this zone, 

chlorite/epidote are the dominant minerals spectrally mapped in the Green Schist Formation. Farther to 

the southeast (stratigraphically upward) discontinuous calcite group minerals occur in Phanerozoic 

rocks. 

Figure 7B–12. Distribution of common alteration minerals in the Haji-Gak area of interest detected in the HyMap 

data. 

7B.3.2.3 Haji-Gak Prospect Subarea: Iron Oxide and Iron Hydroxide Minerals

Figure 7B–21 shows the distribution of Fe-oxides and Fe-hydroxides in the Haji-Gak Prospect 

subarea. The ferric iron (goethite) minerals are mapped as discontinuous pixels along the iron-oxide 

trend between the Haji-Gak and Rokul mineral occurrences. An anomalous area in the northwest corner 

(northwest of the Haji-Gak deposit) shows abundant goethite distal to Haji-Gak deposit mineralization. 

The easternmost border of the subarea continues the iron-oxide trend to the northeast, and a spatially 

distinct concentration of goethite pixels is seen within Phanerozoic rocks in the southeast part of the 

AOI.
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 515

Figure 7B–13. Map showing the known mineral occurrences in the Haji-Gak Prospect subarea of the Haji-Gak

area of interest. 

7B.3.2.4 Haji-Gak Prospect Subarea: Common Secondary Minerals

There are few occurrences and scattered distribution of common secondary minerals (fig.7B–22) 

in the area. The northeast-trending Green Schist Formation is spectrally mapped as containing chlorite 

and (or) epidote group minerals (southeast of the Haji-Gak-Rokul iron-oxide mineral-occurrence trend). 

The Harzar iron and Chapkul and Rokul barite deposits are located in the Haji-Gak Prospect subarea. Of 

note, an anomalous region in the northwest corner (northwest of the Haji-Gak deposit) shows abundant 

chlorite/epidote and serpentine occurrences (King, Johnson, and others, 2011).

7B.3.2.5 Haji-Gak Prospect Subarea: Common Alteration Minerals

Similar to the common secondary minerals map above (fig. 7B–22), common alteration materials 

detected in the HyMap data (fig. 7B–23) within the area are primarily chlorite/epidote group minerals 

that are mapped in the regions described in the previous section. A small, spatially coherent group of 

calcite-clay mineral pixels occur in the west-central part of image (Haji-Gak deposit area) and within 

Phanerozoic age rocks at the southeast corner of the subarea. 
516 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–14. Shaded-relief map showing elevation in the Haji-Gak Prospect subarea of the Haji-Gak area of 

interest. The darker brown tones indicate higher elevations, and lower elevations are represented by the green

tones.

7B.3.3 Northeast Haji-Gak Subarea

The known mineral occurrence map (semi-transparent geologic map overlain on a shaded-relief 

image) shows the position of reported mineral occurrences in the Northeast Haji-Gak subarea 

(fig. 7B–24). Iron-mineral occurrences include the Khaish, Chuy, Zerak, and Sausang deposits, along 

with the Zarak vein barite. Khaish, the largest iron prospect, located near Haji-Gak, is hosted within the 

same rock units as the Haji-Gak deposit. Chuy occurs within a quartz-chlorite schist host rock with 

hematite-magnetite mineralization. Zerak also contains hematite-magnetite mineralization (Abdullah 

and others, 1977; Peters and others, 2007). 

The topography in the subarea ranges from 2,686 to 4,600 m and trends southwest-northeast 

(fig. 7B–25). Figure 7B–26 shows the distribution of Late Proterozoic rocks along the northern side and 

younger Paleozoic units on the south side of the subarea. Fault-bounded wedges of Late Devonian to 

Mississippian age rocks occur in the middle of the subarea. All units have a northeast-trending strike 

parallel to the ridge crest.

In the Landsat TM data (Davis, 2007), the Paleozoic age rocks occur within moderate 

topographic relief in the southern half of the subarea and older Proterozoic rocks form the steeper 

sloping southern ridge area and the north slope (fig.7B–27). The majority (five of six) of the known 
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 517

mineral occurrences in the Northeast Haji-Gak subarea occur in rocks of Late Proterozoic age (see 

fig. 7B–24). 

Figure 7B–15. Geologic map of the Haji-Gak Prospect subarea of the Haji-Gak area of interest (AOI) taken from 

the Russian 1:500,000-scale geologic map of Afghanistan (Dronov and others, 1972). The intrusive rocks are 

exposed in the southwestern part of the AOI.

The overall-inclusive HyMap data for the area show the distribution of iron-bearing (fig. 7B–28) 

and carbonate, phyllosilicate, sulfate, alteration minerals, and other materials (fig. 7B–29). Dry 

vegetation (brown pixels, figs. 7B–28 and 7B–29) is abundant throughout the entire subarea, but is most 

pervasive on the north-sloping rock faces. The presence of the dry vegetation masks much of the northfacing surface and reduces the mineral identification in these areas. Known mineralization (iron and 

barite) occur within regions of abundant ferrous and ferric iron, muscovite (sericite or illite), other clay, 

and calcite. This group of minerals, mixed with dispersed zones of ferrihydrite (and calcite as shown in 

fig. 7B–29), occurs on the ridgeline and top of the southern slope. A circular-like feature of ferrous iron 

(blue) is situated within another discontinuous northeast trend of ferrous-iron-bearing minerals south of 

the ridgeline. Much of the Paleozoic rock on the southeastern side of the subarea also contains abundant 

ferric iron and a small zone of hematite occurs to the southeast (fig. 7B–28). 

7B.3.3.1 Northeast Haji-Gak Subarea: Carbonate Minerals

Figure 7B–30 shows widespread distribution of carbonate-rich rocks over the entire AOI. Calcite 

group minerals are by far the dominant mineral groups mapped in the HyMap data. The Paleozoic age 
518 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

rocks contain abundant calcite pixels in the central part of the image, whereas kaolinite occurs to the east 

and west, near the Proterozoic-Paleozoic contact (see blue areas in fig. 7B–30 and fig. 7B–24). Calcite 

with mica and clay and zones of kaolinite occur along the southern border of the subarea. 

Figure 7B–16. Numerous faults and fractures of different orientations and extent occur in the Haji-Gak Prospect 

subarea of the Haji-Gak area of interest. The fault traces (Peters and others, 2007) are placed on Landsat Thematic 

Mapper (TM) images (Davis, 2007). Marked color differences in the TM data are associated with rocks of different 

ages.

7B.3.3.2 Northeast Haji-Gak Subarea: Clays and Micas

Figure 7B–31 shows the enrichment of phyllosilicates in the Northeast Haji-Gak subarea. 

Muscovite (light-orange pixels) with zones of kaolinite (blue pixels) and other clay minerals are mapped 

as a band following the ridgeline. A second discontinuous band of similar composition parallels the first 

to the south. Both bands are located over areas that host known iron prospects (fig. 7B–24). The early 

Paleozoic age rock (fig. 7B–24) in the central part of the clay/mica image is associated with calcite-clay, 

and the younger Paleozoic rocks to the southeast are characterized by a mixture of calcite-clay group 

minerals, muscovite, and kaolinite. Within this subarea, regions of Proterozoic rock mapped as 
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 519

muscovite (sericite/illite) and minerals containing ferrous and ferric iron, with possibly kaolinite and 

calcite, suggest permissible lithologies for sed-ex hosted iron deposits. 

Figure 7B–17. Image showing iron-bearing and other alteration minerals detected in the HyMap data for the HajiGak Prospect subarea of the Haji-Gak area of interest. 

7B.3.3.3 Northeast Haji-Gak Subarea: Iron Oxides and Iron Hydroxides

The distribution of Fe-oxides and Fe-hydroxides is shown in figure 7B–32. Goethite dominates 

the subarea and defines regions of weathered rock abundant in iron-bearing minerals. The contact zone 

between the goethitic minerals along the southwest-northeast trending ridgeline and the Proterozoic and

Paleozoic age rocks defines an important zone of potential iron mineralization. Grain size of the goethite 

may be important along this iron-mineralization trend (along the ridgeline); the crystallinity of goethite 

is coarse-grained. Abundant goethite is also mapped in the Paleozoic rocks to the southeast, along with a 

small zone of hematite. Minor occurrences of ferrihydrite are located south of the goethite trending near 

the ridgeline that increase eastward in abundance. 
520 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–18. Map showing distribution of clays, carbonates, phyllosilicates, sulfates, altered minerals, and other 

materials for the Haji-Gak Prospect subarea of the Haji-Gak area of interest based on the HyMap data.

7B.3.3.4 Northeast Haji-Gak Subarea: Common Secondary Minerals

There are few occurrences of common secondary minerals (fig.7B–33), with the exception of 

serpentine and the chlorite or epidote group that are mapped in two small concentrated regions within 

upper Paleozoic rocks. These minerals, combined with the structure and geomorphology expressed 

within the Landsat TM image (fig. 7B–27),suggest potential mineral alteration of the country rock 

through weathering, skarn formation, or hydrothermal fluid flow. 

7B.3.3.5 Northeast Haji-Gak Subarea: Common Alteration Minerals

The only significant common alteration minerals mapped in the imaging spectrometer data are 

the kaolinite group minerals and the previously mentioned chlorite or epidote group minerals 

(fig. 7B–34). Local areas of spatially abundant kaolinite is present at or near the northern edge of 

calcite-rich rocks and appear to be positioned close to the contact of older Proterozoic rocks with 

younger Paleozoic limestones (about lat 34°

48' N., long. 68° 22' E). The kaolinite maps as strings of 

small, spatially distinct pixel groups with well-defined cores. Kaolinite is also common as a 

discontinuous dispersed band of pixels along the southern edge of the subarea. 
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 521

Figure 7B–19. Map showing the distribution of carbonate-bearing minerals in the Haji-Gak Prospect subarea 

detected in the HyMap data.

7B.3.4 Farenjal Subarea

The known mineral occurrence map (semi-transparent geologic map overlain on a shaded-relief 

image) shows the position of reported mineral occurrences in the Farenjal subarea (fig. 7B–35), 

including the Dara-i-Neel iron, Farenjal talc, Farenjal bedded barite, Northern Farenjal vein barite, 

Tanghi-Loli, three unnamed occurrences of barite (unknown type), Farenjal manganese (unknown type), 

and Surkh-i-Parso (unknown mineral and type). All the known barite occurrences are hosted in 

Ordovician age rock, with the Farenjal bedded barite, manganese, and talc mineralization occurring near 

a contact zone between Ordovician and Mississippian age rocks (fig. 7B–35). The Dara-i-Neel iron 

occurrence comprises martite float (Kusov and others, 1965). 

The topography in the subarea ranges from 1,900 to 3,832 m with the Gorband River flowing 

eastward through its center. A second river flows northward into the Gorband River with the confluence 

at the center of the subarea (fig. 7B–36). The Proterozic rock that hosts the Haji-Gak iron-bearing 

deposits is fault bounded and pinches out within this subarea; younger lithologies dominate this region 

(fig. 7B–37). Of note, the Dara-i-Neel iron occurrence is located on the northern edge of the Proterozoic 

rock in (or near) fault contact with upper Paleozoic rocks (fig. 7B–35). 
522 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–20. Mapped distribution of clays and micas detected using the HyMap data. The figure shows the 

occurrence of muscovites and illites, chlorite and (or) epidote, and kaolinite group minerals along the southwestnortheast lithologic trend.

In the Landsat TM data (Davis, 2007), the Proterozoic and Paleozoic rocks occur within areas of 

moderate topographic relief and can usually be traced by color within their fault-bounded blocks that are 

defined by the fault traces shown in fig. 7B-38. Changes in surface color represent spectral differences 

in surface mineralogy.

The overall-inclusive imaging spectrometer data for the area show the distribution of ironbearing minerals (fig. 7B–39) and carbonate, phyllosilicate, sulfate, alteration minerals, and other 

materials (fig. 7B–40). Dry vegetation (brown pixels) is sparse in the subarea. Known mineralization 

(iron and barite) occurs in the northern part of the image within regions of spatially well-defined pixels 

of ferrous iron, muscovite, and calcite. 

A complex mixture of minerals are mapped in the subarea. Abundant ferrous-iron-group 

minerals along with calcite, serpentine, chlorite or epidote are mapped in the northwest part of the 

subarea (above and to the west of the confluence of the Gorband River with the second primary river 

flowing in from the south). Muscovite occurs in the northern one-third of the image, north of the 

Gorband River, and is commonly associated with Ordovician age rocks that host the barite deposits (in 

the north-central part of the subarea; fig. 7B–35). In the southern part of the image, the Proterozoic rocks 

host ferrous-iron minerals and associated dolomite with spatially isolated pods of hematite and other 
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 523

ferric-iron minerals in contact zones with Paleozoic strata. Goethite minerals dominate the rest of the 

subarea. Kaolinite group minerals with dolomite dominate the south-central region of the image.

Figure 7B–21. Map showing the distribution of iron hydroxides and iron oxides for the Haji-Gak Prospect 

subarea.

7B.3.4.1 Farenjal Subarea: Carbonate Minerals

Figure 7B–41 shows widespread distribution of minor, discontinuous carbonate and carbonate 

group mineral-bearing rocks over the entire Farenjal subarea. An abundant zone of calcite pixels trends 

west to east through most of the image along the northern edge of the Gorband River, looping and 

cutting across Ordovician and Mississippian age lithologies. This calcite is mapped together with 

ferrous-iron minerals, serpentine, chlorite or epidote, and known barite prospects (see locations within 

fig. 7B–41) on the northwestern side of the subarea. Dolomite with kaolinite and other clay (and with 

ferrous iron and chlorite (or) epidote) is mapped in Proterozoic age terrain east of Dara-i-Neel, as well as 

northward within Mississippian age units (see fig. 7B–35). 

7B.3.4.2 Farenjal Subarea: Clays and Micas

Figure 7B–42 shows the enrichment of phyllosilicates in the Farenjal subarea. Abundant 

muscovite (lighter orange pixels) occurs in much of the subarea. The kaolinite-, dolomite-, and chloriteor epidote-bearing areas are described above with the carbonate minerals.
524 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–22. Image showing the very limited occurrence and scattered distribution of common secondary 

minerals detected in the HyMap data. A coherent grouping of secondary minerals occurs along the lithologic trend 

in the center of the image and in the northwestern part of the AOI.

7B.3.4.3 Farenjal Subarea: Iron Oxides and Iron Hydroxides

The distribution of Fe-oxides and Fe-hydroxides is shown figure 7B–43. Goethite dominates the 

subarea and is mapped in regions of weathered rock abundant in iron-bearing minerals. Goethitic group 

minerals are less abundant in the northeast edge of the image and are not mapped in the western 

one-third of the image, because (undisplayed) ferrous-iron pixels are dominant and occupy these pixel 

sites. Hematite and ferrihydrite occur near and along contacts of Proterozoic and Paleozoic rocks with 

Pliocene deposits in the southern part of the subarea. 

7B.3.4.4 Farenjal Subarea: Common Secondary Minerals

There are few occurrences of common secondary minerals (fig.7B–44), with the exception of 

serpentine and chlorite or epidote group minerals. A prominent zone of these minerals occur along the 

northern edge of the Gorband River near the Tangi-Loli mineral occurrence and southeast of the 

Gorband River confluence. Chlorite is also located within or near faulted rock contacts to the northeast 

(near and north of the barite occurrences). Proterozoic age rocks containing serpentine (along with 

ferrous-iron minerals, dolomite, and clay) occur in the southern region of the image (see carbonate 

minerals section above). 
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 525

7B.3.4.5 Farenjal Subarea: Common Alteration Minerals

The only significant common alteration minerals mapped are the previously mentioned 

(carbonate minerals section) kaolinite and chlorite or epidote group minerals (fig. 7B–45). Chlorite 

occurrences are abundant to the north, whereas kaolinite group minerals dominate the central and 

southern regions. 

Figure 7B–23. Common alteration materials detected in the HyMap data are limited primarily to chlorite or epidote 

and kaolinite group minerals. A coherent grouping of secondary minerals occurs along the lithologic trend in the 

center of the image and in the northwestern part of the AOI.

7B.4 Summary 

The Haji-Gak area of interest (AOI) is well-exposed and is readily mapped using HyMap 

imaging spectrometer data. The HyMap data mapped the well-defined lithologic sequence in the AOI 

and supports the previous field mapping (Kusov and others, 1965), especially in the important ore 

deposit area at the western side of the AOI. Permissive areas of iron mineralization and sericitic 

wallrock alteration trend northeastward through the Northeast Haji-Gak subarea and terminate at the 

eastern side of the AOI within the Farenjal subarea (as seen within HyMap data analysis).
526 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–24. Map showing the known mineral occurrences in the Northeast Haji-Gak subarea of the Haji-Gak

area of interest.

Within the Northeast Haji-Gak subarea, known mineralization (iron and barite) occurs within 

The Haji-Gak Prospect subarea contains well-exposed iron deposits hosted within Late Proterozoic 

rocks on the southeast flank of an anticline. The stratigraphic succession is mapped within the HyMap 

data, and additional iron mineralization is mapped as ferrous-iron minerals, goethite, sericite, and lesser 

amounts of ferric minerals and chlorite or epidote group minerals. 

The subarea includes five iron deposits and one vein-barite deposit.

regions of abundant ferrous and ferric iron, clays and mica (sericite or illite), and calcite. A linear 

trend of this mineral group follows the major topographic ridgeline northeast into the Farenjal subarea. 

Zones of kaolinite may be associated with this trend. 

The Farenjal subarea marks the termination of the iron-bearing trend described above. Known 

barite mineralization occurs that appears to be associated with internal faulting of Ordovician age rocks 

near areas containing abundant ferrous-iron minerals and calcite, serpentine, chlorite and (or) epidote 

and with or without muscovite. 
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 527 

Figure 7B–25. Shaded-relief map showing the elevation of the Northeast Haji-Gak subarea. The darker brown 

tones indicate the higher elevations and the lower elevations are represented by the green tones. Two rivers bound 

the area outside the subarea; both rivers flow in the southwest-northeast direction with tributaries draining into them 

from the northwest and southeast.
528 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–26. Geologic map of the Northeast Haji-Gak subarea of the Haji-Gak area of interest taken from the 

1:500,000-scale geologic map of Afghanistan (Dronov and others, 1972).
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 529

Figure 7B–27. The fault traces (Peters and others, 2007) are placed on Landsat Thematic Mapper (TM) images 

(Davis, 2007). Color difference in the TM data correlate with different geologic units.
530 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–28. The iron-bearing and other alteration minerals detected in the HyMap data of the Northeast

Haji-Gak subarea are shown in this image.
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 531

Figure 7B–29. Map showing the distribution of clays, carbonates, phyllosilicates, sulfates, altered minerals, and 

other materials for the Northeast Haji-Gak subarea of the Haji-Gak area of interest using the HyMap data.
532 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–30. Map showing the distribution of carbonate-bearing minerals in the Northeast Haji-Gak subarea 

detected in the HyMap data. The figure shows calcite, kaolinite, and dolomite within Paleozoic rocks in the southern 

half of the image.
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 533

Figure 7B–31. Map showing the distribution of clays and micas in the Northeast Haji-Gak subarea that were 

mapped using the HyMap data. The figure shows the occurrence of muscovites and illites, chlorite or epidote, and 

kaolinite group minerals.
534 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–32. Map showing the distribution of iron hydroxides and iron oxides for the Northeast Haji-Gak

subarea.
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 535

Figure 7B–33. Image showing the very limited occurrence of common secondary minerals detected in the HyMap 

data for the Northeast Haji-Gak subarea.
536 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–34. Common alteration materials detected in the HyMap data are shown on this map.
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 537

Figure 7B–35. Map showing the known mineral occurrences in the Farenjal subarea of the Haji-Gak area of 

interest. The subarea includes iron, barite, manganese, and talc deposits.
538 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–36. Shaded-relief map showing the elevation of the Farenjal subarea. The darker brown tones indicate 

the higher elevations and the lower elevations are represented by the green tones. The Gorband River flows west to 

east through the middle of the subarea, where it is joined by tributaries flowing from the north and south.
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 539

Figure 7B–37. Geologic map of the Farenjal subarea of the Haji-Gak area of interest is taken from the Russian 

1:500,000-scale geologic map of Afghanistan (Dronov and others, 1972.)
540 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–38. The fault traces (Peters and others, 2007) are placed on a Landsat Thematic Mapper (TM) image 

(Davis, 2007). Color difference in the TM data correlate with different geologic units.
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 541

Figure 7B–39. Map showing the iron-bearing and other alteration minerals detected in the HyMap data for the 

Farenjal subarea.
542 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–40. Map showing the distribution of clays, carbonates, phyllosilicates, sulfates, altered minerals, and 

other materials for the Farenjal subarea of the Haji-Gak area of interest using the HyMap data.
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 543

Figure 7B–41. Map showing the distribution of carbonate-bearing minerals in the Farenjal subarea detected in 

the HyMap data. The figure shows zones of abundant calcite, kaolinite, and dolomite.
544 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–42. Map showing the distribution of clays and micas in the Farenjal subarea that were mapped using 

the HyMap data. The figure shows the occurrence of muscovites and illites, chlorite or epidote, dolomite, and 

kaolinite group minerals.
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 545

Figure 7B–43. Map showing the distribution of iron hydroxides and iron oxides for the Farenjal subarea.
546 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

Figure 7B–44. Map showing the very limited occurrence of common secondary minerals detected in the HyMap 

data for the Farenjal subarea of the Haji-Gak area of interest. 
Chapter 7B. Analysis of Imaging Spectrometer Data for the Haji-Gak Area of Interest 547

Figure 7B–45. Map showing the common alteration materials detected in the HyMap data for the Farenjal 

subarea. 

7B.5 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, 1:500,000 scale. 

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 (2nd edition): Kabul, 

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

Clark, R.N., Swayze, G.A., Livo, K.E., Kokaly, R.F., King, T.V.V., Dalton, J.B., Vance, J.S., Rockwell, 

B.W., Hoefen, T., and McDougal, R.R., 2003a, Surface reflectance calibration of terrestrial imaging 

spectroscopy data: A tutorial using AVIRIS, in Green, R.O., ed., Proceedings of the 11th JPL Airborne 

Earth Science Workshop: JPL Publication 03-4, p. 43-63. 

Clark, R.N., Swayze, G.A., Livo, K.E., Kokaly, R.F., Sutley, S.J., Dalton, J.B., McDougal, R.R., and 

Gent, C.A., 2003b, Imaging spectroscopy: Earth and planetary remote sensing with the USGS 

Tetracorder and Expert Systems: Journal of Geophysical Research, v. 108, no. E12, 5131, 

doi:10.1029/2002JE001847, 44p. 

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. 
548 Summaries of Important Areas for Mineral Investment and Production Opportunities of Nonfuel Minerals in Afghanistan

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

Open-File Report 2007–1029, 22 p.

Doebrich, J.L., and Wahl, R.R., comps., with contributions by Doebrich, J.L., Wahl, R.R., Ludington, 

S.D., Chirico, P.G., Wandrey, C.J., Bohannon, R.G., Orris, G.J., Bliss, J.D., Wasy, Abdul, and 

Younusi, M.O., 2006, Geologic and mineral resource map of Afghanistan: U.S. Geological Survey 

Open File Report 2006-1038, scale 1:850,000, available at 

Dronov, V.I., Kalimulin, S.M., Sborshchikov, I.M., Svezhentsov, V.P., Chistyakov, A.N., Zelensky,

E.D., and Cherepov, P.G., 1972, The geology and minerals of North Afghanistan (parts of map sheets 

400-II and 500-I, the Kaysar-Hari Rod Interfluve area): Kabul, DGMS, 44.

http://pubs.er.usgs.gov/usgspubs/ofr/ofr2005103.

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/

King, T.V.V., Kokaly, R.F., Hoefen, T.M., and Knepper, D.H., 2010, Resource mapping in Afghanistan 

using HyMap data, in Proceedings of the 15th Australasian Remote Sensing and Photogrammetry 

Conference, Alice Springs, Australia, September 12–17, 2010, p. 500, available at 

.

http://dl.dropbox.com/u/81114/15ARSPC-Proceedings.zip/

King, T.V.V., Johnson, M.R., Hoefen, T.M., Kokaly, R.F., and Livo, K.E., 2011, Mapping potential 

mineral resource anomalies using HyMap data, in King, T.V.V., Johnson, M.R., Hubbard, B.E., and 

Drenth, B.J., eds, Identification of mineral resources in Afghanistan—Detecting and mapping resource 

anomalies in prioritized areas using geophysical and remote sensing (ASTER and HyMap) data in 

Afghanistan: U.S. Geological Survey Open-File Report 2011–1229, available at 

.

http://pubs.usgs.gov/of/2011/1229/

King, T.V.V., Kokaly, R.F., Hoefen, T.M., Dudek, K. and Livo, K.E., 2011, Surface materials map of 

Afghanistan—Iron-bearing minerals and other materials: U.S. Geological Survey Scientific 

Investigations Map 3152–B.

.

Kokaly, R.F., King, T.V.V., and Livo, K.E., 2008, Airborne hyperspectral survey of Afghanistan 

2007—Flight line planning and HyMap data collection: U.S. Geological Survey Open-File Report 

2008–1235, 14 p.

Kokaly, Ray, 2011, PRISM—Processing routines in IDL for spectroscopic measurements: 

U.S. Geological Survey Open-File Report 2011–1155, available at http://pubs.usgs.gov/of/2011/1155/

Kokaly, R.F., King, T.V.V., Hoefen, T.M., Dudek, K. and Livo, K.E., 2011, Surface materials map of 

Afghanistan—Carbonates, phyllosilicates, sulfates, altered minerals, and other materials: U.S. 

Geological Survey Scientific Investigations Map 3152–A.

.

okaly, R.F., 2010, Spectroscopic remote sensing for material identification and mapping, 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/81114/15ARSPCProceedings.zip/.

Kusov, I.K., Smirnov, M.S., and Reshetniak, V.V., 1965, Report of the results of prospecting-survey and 

reconnaissance works for iron ores in central Afghanistan with reserve calculation of Hajigak Deposit 

for 1963-1964: USSR v/o Technoexport, contract no. 640, 3 volumes with English translation, Royal 

Government of Afghanistan, Ministry of Mines and Industries internal report, contract No. 640, 

Kabul, unpub. data, 269 p.

Peters, S.G., Ludington, S.D., Orris, G.J., Sutphin, D.M., Bliss, J.D., and Rytuba, J.J., eds., and the U.S. 

Geological Survey-Afghanistan Ministry of Mines Joint Mineral Resource Assessment Team, 2007, 

Preliminary non-fuel mineral resource assessment of Afghanistan: U.S. Geological Survey Open-File 

Report 2007–1214, 810 p., 1 CD–ROM. (Also available at http://pubs.usgs.gov/of/2007/1214/.)