Geographic Information System (GIS) Representation of 

Coal-Bearing Areas in India and Bangladesh

Compiled by Michael H. Trippi and Susan J. Tewalt

Open-File Report 2011–1296

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia 2011

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Trippi, M.H., and Tewalt, S.J., comps., 2011, Geographic information system (GIS) representation of coal-bearing 

areas in India and Bangladesh: U.S. Geological Survey Open-File Report 2011–1296, 27 p., available only at

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copyright owners to reproduce any copyrighted material contained within this report.
ii

Contents

Overview........................................................................................................................................................................ 1

India ............................................................................................................................................................................... 1

GIS methodology........................................................................................................................................................ 8

Stratigraphy of the India coal-bearing sections......................................................................................................... 10

Gondwana coal..................................................................................................................................................... 12

Tertiary coal.......................................................................................................................................................... 13

Coal chemistry.......................................................................................................................................................... 14

Bangladesh .................................................................................................................................................................. 15

GIS methodology...................................................................................................................................................... 17

Stratigraphy of the Bangladesh coal-bearing sections.............................................................................................. 17

Gondwana coal..................................................................................................................................................... 19

Tertiary coal.......................................................................................................................................................... 19

Coal chemistry.......................................................................................................................................................... 19

Acknowledgments........................................................................................................................................................ 19

References Cited ......................................................................................................................................................... 20

Figures

1. Coalfields within States of India............................................................................................................................ 9

2. Correlation chart of stratigraphic units of the coalfields of India, indicating formation and group names............ 11

3. Coalfields of Bangladesh with names................................................................................................................. 16

4. Correlation chart of stratigraphic units in the coalfields of Bangladesh, indicating formation 

and group names. ........................................................................................................................................... 18

Tables

1. List of coalfields by State or Union territory in India.............................................................................................. 3

2. List of coalfields by district (previous to changes of names on January 25, 2010) in Bangladesh...................... 17
iii

Conversion Factors

Inch/Pound to SI

Multiply By To obtain

Length

foot (ft) 0.3048 meter (m)

mile (mi) 1.609 kilometer (km)

yard (yd) 0.9144 meter (m)

Area

acre 0.004047 square kilometer (km2)

square mile (mi2) 2.590 square kilometer (km2) 

Mass

tonne (t) (2205 lb)

tonne (t) (2205 lb)

ton, short (2,000 lb)

1

.028316

0.9072

Megagram (Mg)

Meters cubed (m3)

megagram (Mg) 

ton, long (2,240 lb) 1.016 megagram (Mg) 

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F=(1.8×°C)+32

Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows:

°C=(°F-32)/1.8
1

Geographic Information System (GIS) Representation of 

the Coal-Bearing Areas of India and Bangladesh

Compiled by Michael H. Trippi and Susan J. Tewalt

Overview

Per capita energy consumption rates in India and Bangladesh are among the lowest in the world 

(Ghosh, 2009; Mondal and others, 2010). Colloquially referred to as “energy poverty” (World Energy 

Council, 2010), the shortage of electric generating capacity necessitates that India and Bangladesh 

continue to use indigenous coal resources, despite significant global environmental issues related to coal 

consumption. The total installed electricity capacity of India as of July 31, 2008, was 145,587.97

megawatts (MW), based on power generation from 53 percent coal, 25 percent hydro-power, 10 percent 

natural gas, 8 percent renewable energy sources, and 3 percent nuclear sources (Ghosh, 2009). In

Bangladesh, only 42 percent of the population in 2006 had access to electricity (Mondal and others, 

2010). The Bangladesh Power Development Board (2011) indicates that Bangladesh has a total installed 

electric generation capacity of 6,760 MW; natural gas is the predominant energy source for electricity. 

Traditional biomass, including wood, agricultural waste, and dung, are the predominant energy sources

in rural Bangladesh. The current supply of electricity in Bangladesh is unreliable, due to natural gas 

availability, power plant inefficiencies, high grid system losses, and electricity theft.

Geographic information system (GIS) information may facilitate energy studies, which in turn 

provide input for energy policy decisions. Prior to this study, no GIS file representing the occurrence of 

coal-bearing units in India or Bangladesh was known to exist. This is what prompted the creation of the 

GIS datasets in this report. The prior U.S. Geological Survey (USGS) methodology of using existing 

GIS surficial geologic shapefiles to select coal-bearing units and use them as a proxy for coalfields 

(Tewalt and others, 2008; Merrill and Tewalt, 2008) was not applicable in India and Bangladesh, where

the mapped surface geology consists largely of alluvial cover or Precambrian rocks (Hearn and others, 

2001). The shapefiles were generally built by scanning published maps or figures that depict the 

graphical extent of coalfields and then digitizing polygonal areas from the scanned files. Accompanying 

metadata contain lists of all map sources. A limited number of chemical and petrographic analyses of 

India and Bangladesh coal samples are included in the GIS point shapefiles. This report provides

supporting information regarding the coal-bearing stratigraphic units for the coalfield GIS shapefiles.

This report is not intended to be an authoritative or comprehensive study of the Permian and 

Tertiary coals that are available for mining and combustion in India and Bangladesh. Publications of the 

Geological Survey of India and the Geological Survey of Bangladesh, as well as many recent research 

journal articles, are available for more detailed information. Lists of the India and Bangladesh coalfields 

are provided in tables 1 and 2, respectively. Brief descriptions of the coal-bearing geologic units follow.

India 

According to the India Ministry of Home Affairs (2011), the 2001 census counted a population

of approximately 1 billion people in India. Coal is the predominant indigenous energy resource 
2

available for use to meet the electrical needs within the republic and will continue to be used into the 

future. Most coal resources are bituminous in rank and Permian (Gondwana) in age; however, Tertiary

coals and lignites are also present. Coalfields cover an area of about 34.7 thousand square kilometers

(km2) of a total land surface of 3.29 million km2 in India (Central Fuel Research Institute, 1993) and are 

shown in figure 1. Peninsular India contains the majority of population and coal resources, but demand 

for electricity in more remote areas (for example, western India) makes the location of local coal 

extremely important. The coalfields of India are listed in table 1 by State or Union territory and geologic 

age. In the myriad number of published reports, there are often multiple names or groupings for 

coalfields and several variations of their spelling. In addition, minor adjustments in geologic age, 

particularly of the Tertiary coals, are reported in more recent articles (for example Rage and others,

2003; Singh and others, 2010). The nomenclature for basin and coalfield names used in this report relies 

heavily on publications of the Geological Survey of India (1981, 1982, 1983, 1987, 2003) and Sastry

and others (1977) for geologic names.
3

Table 1. List of coalfields by State or Union territory in India.

[*, fields are not in GIS shapefile]

State or Union territory Group of fields or basin Coalfield/lignite occurrence name or area (subarea) Geologic age

Andhra Pradesh2 Pranhita-Godavari Valley

Palar Basin

Chinnur area, Manuguru area, Ramagundam-Mantheni area, 

Indaram-Jaipuram area

Wardha Valley

Eluru-Rajamundri

Permian

 ′′

Tertiary (Eocene)

Tertiary (Miocene-Pliocene)

Arunachal Pradesh1 Namchik-Namphuk

Makum

Unnamed fields1

/Abor Hills, Aka Hills, Miri Hills, Daphala 

Hills8

Miaobum9

*

Tertiary (Oligocene-Miocene)

 ′′

 ′′

 ′′

Assam1 Mikir Hills (Koilajan9*, Selvetta9*, Khunbaman9*)

Makum

Dilli-Jaipore

North Cachar Hills9

* (Lengloi, Deigrung)

Diphu9

*

Tertiary

Tertiary (Oligocene-Miocene)

 ′′

 ′′

 ′′

Chhattisgarh3 Lakhanpur Group

Lakhanpur Group

Lakhanpur

Sendurgarh, Damhamunda, Panchbhaini

Chirimiri 

Hasdo-Arand

Korba

Mand-Raigarh

Bisrampur

Sonhat

Jhilimili

Tatapani-Ramkola

Permian

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′
4

Table 1. List of coalfields by State or Union territory in India.—Continued

[*, fields are not in GIS shapefile]

State or Union territory Group of fields or basin Coalfield/lignite occurrence name or area (subarea) Geologic age

Gujarat6—continued Umarsar 

Mudia

Jularai

Lefri

Waghapadar

Fulradam

Kaiyari

Ahkrimota

Hamla

Nanaratadia

Bhuri

Lakhanka Karsalia

Tertiary

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

Jammu and Kashmir3,6 Kalakot, Metka, Mahogala

Chakkar

Jangalgali

Chinkah

Lodhra

Ladda

Firozpur Shaliganga

Nichahom Baramula

Nagbal

Unnamed field (Dhansal-Sawalkot9

)

Tertiary

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

Jharkhand4

Damodar Valley

Damodar Valley

Damodar Valley

Rajmahal Group

Ramgarh

West Bokaro

East Bokaro

Chope

North Karanpura

South Karanpura

Giridh

Deoghar (Saharjuri, Jainti, Kundit-Kuraiah)

Jharia8

Mahuagarhi, Brahmani, Pachwara, Chuperbhita, Hura

Raniganj

Permian

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′
5

Table 1. List of coalfields by State or Union territory in India.—Continued

[*, fields are not in GIS shapefile]

State or Union territory Group of fields or basin Coalfield/lignite occurrence name or area (subarea) Geologic age

Jharkhand4—continued Auranga

Hutar

Daltonganj

Itkhori

Permian

 ′′

 ′′

 ′′

 

Kerala6 Nileswaram

Madayi

Warkala

Tertiary (Miocene-Pliocene)

 ′′

 ′′

Madhya Pradesh3 Satpura Basin

Satpura Basin

Satpura Basin

Tawa Valley (Sonada, Gurgunda, Shahpur, Dulhara, 

Pathakhera)

Kanhan-Pench Valley

Mohpani

Umaria-Korar

Johilla

Sohagpur (Jhagrakhand-Bijuri, Kotma, Burhar-Amlai)

Singrauli

Permian

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

Maharashtra2 Wardha Valley

Bandar

Umrer

Kamptee

Ratnagiri

Permian

 ′′

 ′′

 ′′

Tertiary

Meghalaya1

Garo Hills

Garo Hills

Garo Hills

Garo Hills

East Khasi Hills

East Khasi Hills

Singrimari

Rongrenggiri

West Daranggiri

Siju

Balphakram-Pendengru, Holwang, Nabru, Zigrik

Langrin

Mawlong-Shella

Cherrapunji Plateau-Mawsynram- Laitryngew

Lyngkyrdem-Pynursla-Thangkinath*

Bapung

Um Rileng

Permian

Tertiary (Eocene)

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′
6

Table 1. List of coalfields by State or Union territory in India.—Continued

[*, fields are not in GIS shapefile]

State or Union territory Group of fields or basin Coalfield/lignite occurrence name or area (subarea) Geologic age

Nagaland1 Janzi-Disai

Borjan (Nazira)

Tiru9

*

Tuensang9

*

Tertiary (Oligocene-Miocene)

 ′′

 ′′

 ′′

Orissa2 Ib River

Talchir

Permian

 ′′

Rajasthan6 Barmer basin Kapurdi

Khari

Gangashahr

Sarup Desar

Mudh

Kolayat

Gura

Bithnok

Palana

Chaneri

Bar Singhsar

Lalmdesar

Mandal Charnan

Raneri

Hiraki Dhani

Kasnau

Kurchera

Nimbri

Marwar Chapri

Butati

Merta Road

Hansiyas

Gangarda

Lamba Jatan

Mokala

Indawar

Nagarda

Nimla

Tertiary (Eocene)

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′
7

Table 1. List of coalfields by State or Union territory in India.—Continued

[*, fields are not in GIS shapefile]

State or Union territory Group of fields or basin Coalfield/lignite occurrence name or area (subarea) Geologic age

Bharka

Botiya

Hamir Ji Ki Dhani

Jalipa

Tertiary (Eocene)

 ′′

 ′′

 ′′

Sikkim7 Rangit Valley Permian

Tamil Nadu2 Cauvery Basin

Palar Basin

Neyveli (East and South areas)

Bahur

Bhubangiri

Srimushnam

Lalpettai

Jayamkonda Cholapuram

Mannargudi

Tertiary (Eocene)

 ′′

 ′′

 ′′

 ′′

 ′′

 ′′

Tertiary (Miocene-Pliocene)

Uttar Pradesh3 Singrauli Permian

West Bengal5

Damodar Valley

Birbhum

Raniganj/Rakshitpur area

Darjeeling7

Barjora

Permian

 ′′

 ′′

1

Geological Survey of India (1981).

2

Geological Survey of India (1982).

3

Geological Survey of India (1983).

4

Geological Survey of India (1987).

5

Geological Survey of India (2003).

6

Geological Survey of India (2006).

7

Ghosh (1997).

8

Central Fuel Research Institute (1993).

9

Atul K. Varma (written commun., 2011).
8

GIS methodology

The Geological Survey of India (GSI) published Bulletin 45 (volumes I through V) between

1981 and 2003 to summarize the extensive geologic knowledge of Indian coal. The volumes 

(Geological Survey of India, 1981, 1982, 1983, 1987, 2003) include coalfield location maps, as well as 

information on coal quality and reserves, and served as the main source for the shapefiles. The plates 

showing the individual coalfields from each volume were scanned and georeferenced to (1) known 

latitude and longitude line intersections based on latitude and longitude “tick” marks from the original 

map or (2) to recognizable deviations in State and national boundary lines and shorelines. Base map 

projection information was unknown. The outlines of coal-bearing formations in the areas depicted on 

plates from Bulletin 45 were digitized and then attributed with field name and source references, but 

geologic formation names were not included. Some interpretative geologic contacts needed to be 

generated, as in the Wardha Valley of Andhra Pradesh and Maharashtra’s Umrer and Kamptee 

coalfields, where interpretive boundaries of areas concealed by alluvium were estimated by USGS 

authors. Also, major igneous intrusions mapped on the plates of Bulletin 45 were designated as noncoal-bearing areas, because the intrusions generally sterilize the coal resource. Maps of detailed 

exploratory coal blocks within Gondwana coalfields are included in a publication (Geological Survey of 

India, 1977) that was not used as a source for the GIS shapefiles. Two coalfield outlines in this GIS 

dataset came from non-GSI publications (Ghosh, 1997). The locations of Tertiary lignite occurrences 

were based mostly on two maps presented by the Geological Survey of India (Geological Survey of 

India, 2006) at an underground coal gasification workshop sponsored by the U.S. Department of 

Energy, the India Ministry of Coal, and Coal India Ltd. Many of the Tertiary coal occurrences in 

western India are concealed by alluvium; thus locations may not be precise in the GIS dataset. The 

metadata file “IndiaCoalfields Metadata.htm” describes all GIS processing.

In general, all areas depicting coalfields or lignite occurrences may not be detailed enough in 

areal extent to use in the calculation of resources. Political boundaries (international and shorelines) 

used in figure 1 are from the U.S. Department of State (2011) and State boundaries are from Hijmans 

and others (2010).
9

Figure 1. Coalfields within States of India. 

Coal chemical and petrographic data for samples related to previous USGS studies in India are 

also included in a point shapefile (Tewalt and others, 2010). The accompanying metadata file is called 

“IndiaAnalyticalData Metadata.htm.” Coal chemistry includes proximate and ultimate analyses from a 

commercial laboratory and major-, minor-, and trace-elements from a USGS laboratory. Additional coal 

quality information on Indian coals, dating back to the 1970s, is available in publications of the Central 

Institute of Mining and Fuel Research, formerly the Central Fuel Research Institute (Central Fuel 

Research Institute, 1979).
10

Stratigraphy of the India coal-bearing sections

India has an extremely complex tectonic history and a stratigraphic succession that is commonly

interrupted by unconformities and disconformities. Figure 2 is a highly generalized composite 

correlation chart (stratigraphic column) for the country, summarized from the text of Geological Survey 

of India’s Bulletin 45 volumes, with some augmentation by Gowrisankaran and others (1987). Figure 2

is idealized in the sense that all correlative units are listed; in actuality, the complete sequence shown 

does not exist in any one region. The text below includes brief descriptions of the Gondwana (Upper

Carboniferous through Lower Cretaceous) and Tertiary coal-bearing units shown in figure 2, grouped by 

geologic age. The descriptions do not fully accommodate the variable nature of the stratigraphic 

sections over such a vast geographic extent and time period but are intended to serve as an introduction 

to the host rocks of Indian coals. A Cretaceous-age coalfield in Gujarat, called Ghuneri, is not included 

in this discussion or the GIS file because no base map was available. Mesozoic coals are not presently 

economically significant resources (SanFilipo and others, 1992).
11

Figure 2. Correlation chart of stratigraphic units of the coalfields of India, indicating formation and group names.
12

Gondwana coal

Gondwana units are thick wedges of clastic sediments deposited in elongated erosional 

intracratonic basins that widened over time (Pareek, 1988) and were deposited from Late Carboniferous 

to the beginning of the Cretaceous. Most coals are found in the lower Gondwana units, deposited during 

the Permian. Many formations are intruded by dolerites and lamprophyres, which locally affect the coal 

beds by increasing rank of the coal. There is controversy regarding the stratigraphic interpretation 

within some of the basins, where fragmentary fossil evidence used for identification conflicts with the 

accepted order of superposition (Dutta, 2001). Eastern Himalayan coals have been influenced by

igneous activity and regional tectonic impacts and are thus often physically different from the peninsular 

India coals.

Upper Carboniferous to Lower Permian

Where sediments of this age exist, the Talchir Formation occurs in many coalfields. The Talchir

Formation contains greenish sandstone and splintery (needle) shale, and unconformably overlies much 

older units—often Proterozoic gneisses or other rock types (Geological Survey of India, 1987). The

Talchir Formation has a boulder bed (tillite) as the basal unit (Geological Survey of India, 1983),

indicating a glacial origin. In small coalfields of Arunachal Pradesh north of the Brahmaputra River, the 

Miri Formation and possibly part of the Rangit Pebble-Slate of the Damuda Group represent this time 

period (Sastry and others, 1977).

Lower to Middle Permian

The Karharbari and Barakar Formations are assigned to the Lower Permian. The Karharbari

Formation is generally composed of coarse sandstones and conglomerates (Geological Survey of India, 

1987). It cannot be distinguished as a formation in all coalfields and is often considered a “stage” of the 

Barakar Formation (Fox, 1934; Sastry and others, 1977). Coals occur within this unit in the coalfields of 

the Damodar Valley and Rajmahal Group of Jharkhand (table 1). The Barakar Formation is a principal 

coal-bearing unit and is often divided into two or three members, with coals preferentially distributed 

among the members. The Barakar Formation coal beds are often thick and extensive. The formation 

achieves a maximum thickness of 1,000 meters (m) in the Sonhat coalfield of Chhattisgarh (Geological 

Survey of India, 1983) and 1,250 m in the Jharia coalfield of Jharkhand (Chandra, 1992). Many of the 

outcropping Barakar Formation coals in the East Bokaro coalfield of Jharkhand are burned (clinker),

and burning has also altered other surficial rock exposures. In the eastern part of Jharkhand, the Jharia 

coalfield has present-day coal fires that cause subsidence of buildings and require relocation of the 

population.

Depending upon the coalfield, the Barakar Formation is cited as being either conformably or

unconformably overlain by the “Barren Measures,” which are a thick sequence of sandstone, sandy 

shale, and black shale. This interval, which is void of exploitable coal, is called the Motur Formation in 

the Satpura Basin coalfields (including the Tawa Valley, Kanhan Valley- Pench Valley, and Mohpani 

coalfields) in Madhya Pradesh, and in the Kamptee field in Maharashtra (Geological Survey of India, 

1983); it is called the “Ironstone Shale” in the Raniganj coalfield of West Bengal (Sastry and others, 

1977).

Upper Permian to Triassic

Informally, the stratigraphic sequence over the Barakar Formation is sometimes referred to as 

the “Supra-Barakar Formations.” In the Satpura Basin of Madhya Pradesh, the Bijori and Panchmari 
13

Formations overlie the Motur Formation (“Barren Measures”). Both formations are largely composed of 

sandstones and shales (Geological Survey of India, 1983). In Jharkhand, the Raniganj Formation 

overlies the Barren Measures and is largely composed of calcareous sandstones, with some

carbonaceous shales. The Raniganj Formation also contains coal in the Singrauli coalfield of Madhya 

Pradesh, the West Bokaro and East Bokaro coalfields of Jharkhand, and the Raniganj coalfield in West 

Bengal (Geological Survey of India, 1987, 2003). The contact of the Raniganj Formation with the

overlying Panchet Formation is often considered the boundary of the Permian and Triassic 

(Bandyopadhyay, 1996). In many areas, the Kamthi Formation (also called the Panchmari Formation) is 

present. Although the Kamthi Formation is largely composed of sandstones, in the Mand-Raigarh and 

Bisrampur coalfields of Chhattisgarh, some coals occur within the Kamthi Formation (Geological 

Survey of India, 1983).

Upper Triassic (Upper Gondwana)

Overlying the sandstones and shales of the Panchet Formation are coarse, often ferruginous 

sandstones lying within the Upper Triassic Mahadeva or Dubrajpur Formations of Jharkhand. In the 

Satpura Basin of Madhya Pradesh, the equivalent unit is called either the Bagra or the Parsora 

Formation (Geological Survey of India, 1983). In the Pranhita-Godavari Valley and Wardha Valley 

coalfields of Andhra Pradesh, the equivalent is called the Maleri Formation (Geological Survey of India, 

1982). Most of these units do not contain coals, although the Dubrajpur Formation does have thin coal 

bands in the Birbhum coalfield of West Bengal (Geological Survey of India, 1987).

Tertiary coal

Tertiary sediments overlie the Deccan Traps, extensive volcanic tuffs and basalts, which were 

deposited from Late Cretaceous to Early Eocene (Krishnan, 1956). The Rajmahal volcanics in 

Jharkhand and West Bengal appear to be slightly older—Early Cretaceous in age (Geological Survey of 

India, 1987, 2003). The Tertiary coals of India constitute a minor portion of Indian coal reserves. 

Tertiary-age lignites are found in northwestern, western, and southern India and are believed to have 

formed at Indian plate margins (Singh and others, 2010). Some lignite fields have coals ranked as high 

as semi-anthracite, which is likely due to maturation caused by deep-seated intrusive bodies (Pareek, 

1988). Most of the lignite occurrences in western India are covered by unconsolidated surficial 

materials, including alluvium and aeolian deposits (Hearn and others, 2001), and it is difficult to 

correlate their stratigraphic position.

Paleocene to lowermost Eocene

The Fulra Dam Formation, composed of gray argillite, sand, and lignite, bears coals in the Mata

No Madh field (Kutch basin) of Gujarat and overlies the Deccan Traps (Sandhro Formation). Coals of 

this age also occur in the Palana lignite field of Rajasthan (Gowrisankaran and others, 1987).

Lower to upper Eocene

In Meghalaya, the Tura Formation, largely composed of sandstone, bears coals in the Garo Hills 

group of coalfields (table 1). This unit is equivalent to the Lakadong Sandstone Member of the Sylhet 

Limestone Formation (SLF) that occurs in other coalfields in Meghalaya (Geological Survey of India, 

1981). The Siju Limestone and Kopili Formation of Meghalaya are devoid of coal. Equivalent units are 

in the Disang Group (gray, splintery shale) in Nagaland and parts of Assam. The coals of Mikir Hills in 

Assam occur within the Jaintia Group and Syhlet Limestone (Singh and others, 2010). 
14

In Jammu and Kashmir, coals occur in the Subathu Group, composed of limestones and shales 

that unconformably overlie a bauxite unit (Geological Survey of India, 1983). The Kalakot and Metka 

coal occurrences of Jammu and Kashmir have middle Eocene coals within the Subathu Group that have 

been altered to higher rank (semi-anthracite) from deep-seated igneous heating. 

In Gujarat, the lower Eocene units include the lower Tharad Formation, the Cambay Shale, the 

Lakhpat Formation (Bandyopadhyay, 1996), and the Naredi Formation (Rage and others, 2003). 

Equivalent units are called the Akli Formation in the Kapurdi lignite area of Rajasthan (Mukherjee and 

others, 1992). The coal-bearing middle Eocene unit in Gujarat is the Harudi Formation (greenish-gray 

shale and lignitic clays) in the Panandhro and Mata No Madh fields. The Panandhro lignites are in strata

believed to be equivalent to the Laki Formation of Sindh, Pakistan (SanFilipo and others, 1992).

Oligocene to Miocene

The Barail Group crops out within Assam, Nagaland, and Arunachal Pradesh and contains 

sandstones and sandy shales. Within the Barail Group, the Tikak Parbat Formation contains coals, 

particularly in the Janzi-Disai and Borjan (Nazira) coalfields of Nagaland (Geological Survey of India, 

1981). The same-age Simsang Formation in Meghalaya is largely silty shale and void of coal, as is the 

Surma Group, which is mostly sandstone and conglomerate in both the Meghalaya’s Langrin coalfield 

and Assam’s Mikir Hills coalfield (Geological Survey of India, 1981).

Miocene to Pliocene

Lignites of Miocene to Pliocene age are found in the States of Kerala, Jammu, and Kashmir. The 

Karewa Formation (Pliocene) (Gowrisankaran and others, 1987) in Jammu and Kashmir contains 

lignites, as well as gray clay, sandy clay, sands, and conglomerates. Jammu and Kashmir coals also 

occur in the Muree Group (Miocene to Pliocene) (Singh and Singh, 1995), which overlies the Eocene 

Subathu Group. The Cuddalore Formation is coal bearing in the Palar Basin (Geological Survey of 

India, 1982) of Tamil Nadu.

Coal chemistry

Indian coals are generally moderate to high in ash yield—quite often around 30 percent on an asreceived basis. Ranges of ash yield and sulfur content can be found in Geological Survey of India 

publications (1977, 1981, 1982, 1983, 1987, 2003). In 2006, there were 37 coal beneficiation plants 

(washeries) in India; 20 are coking coal washeries and 17 are for non-coking coal (Arora and others, 

2006). Coal of coking quality is not widespread but occurs in the Jharia and Raniganj coalfields of 

Jharkhand and in a few coalfields in Madhya Pradesh. Tertiary coals in northeastern India are higher in 

sulfur than the Gondwana coals. As an example, the Dilli-Jaipore coalfield of Assam has coals that 

average approximately 6 percent total sulfur (Geological Survey of India, 1981). The lignites of 

southern and western India are lower in rank and thus higher in moisture (Sharma and others, 2004). 

Permian-age coal samples in the analytical data GIS point shapefile (only from the Sohagpur coalfield

of Madhya Pradesh) have a range for ash yield of 8.53 to 63.09 percent and a total sulfur range of 0.1 to 

2.34 percent. The few Tertiary-age coal samples in Rajasthan show ash yields of 9.58 to 43.79 and 

sulfur from 3.31 to 13.89 on an as-received basis (Tewalt and others, 2010). Other data sources should 

be used to supplement the limited analytical and petrographic data presented here. 
15

Bangladesh 

Bangladesh is approximately 140,000 km2 in area (BANBEIS, 2011) and is home to 160 million 

people as of 2008 (Fong-Sam and others, 2010). The major indigenous non-renewable resource in 

Bangladesh is natural gas (Islam and Hayashi, 2008), with an estimated 32.1 trillion cubic feet (TCF) of 

undiscovered, conventional, natural gas resources in the country (USGS-Bangladesh Gas Assessment 

Team, 2001; Persits and others, 1997). Traditional biomass, as well as natural gas and imported fuel, 

provides the majority of electricity. However, the government plans to generate 2,900 MW of power 

from coal in the next 5 years (Mondal and others, 2011). Bangladesh coals formed in the same time 

periods (Permian and Eocene) in which coal-bearing units in India formed but are much less extensive

(fig. 3). Between 1962 and 1997, five Permian (Gondwana) coalfields were discovered in Bangladesh 

(table 2). Not all Gondwana basins have coal that can be easily produced; some coal occurs at depths 

that exceed current exploitation capability, such as the Jamalganj coalfield where depths to coal can 

exceed 1,000 m. From 2005 to 2009, Bangladesh coal production grew from 85,000 to 96,000 short tons 

(Energy Information Agency, 2011). Bangladesh also plans to diversify its electrical generation capacity 

through nuclear power and is investigating coalbed methane production and geothermal potential as 

well (Guha and others, 2010). The government published a renewable energy policy in 2008.
16

Figure 3. Coalfields of Bangladesh with names.
17

Table 2. List of coalfields by district (previous to changes of names on January 25, 2010) in Bangladesh. 

[*, fields are not in GIS shapefile]

District and Upizila

(Subdistrict)

Coalfield name or 

area Geologic age

Dinajpur District Barakupuria2 Permian

Dinajpur District Phulbari2 Permian

Dinajpur District Dighipara2 Permian

Rangpur District Khalashpir1 Permian

Jaipurhat Upazila of

Bogra District

Jamalganj2

Permian

Dinajpur District Nawabgonj3 Permian

Dinajpur District Dangapara3 Permian

Bandarban District Lamakata1 Eocene

Sunamganj Upizila

of Sylhet District

Bhangarghat1

Eocene

Chittagong District Patiya4 Eocene

Sylhet District Lubachhara4

* Eocene

1

Landis and others (1991).

2

Islam and Hayashi (2008).

3

Muller (2009).

4

Banglapedia (2006).

GIS methodology

Permian-age basins of Bangladesh are small in areal extent and have no surficial expression, 

being overlain by Tertiary and Quaternary deposits (Islam and Hayashi, 2008). Figures from research 

articles and administrative reports of the USGS were used to approximate the location of coalfields for 

the shapefile, with sources noted in the metadata file (“BangladeshCoalfields Metadata.htm”). Political 

boundaries (international and shorelines) used in figure 3 are from the U.S. Department of State (2011) 

and district and upazila boundaries are from Hijmans and others (2010). The point shapefile has only 

partial chemical analyses for three of the five drill holes presented, as well as limited sample depths in 

core GDH-40. Proximate and ultimate analyses are not available. Petrographic analyses are from 

Bostick and others (1991) and major-, minor-, and trace-element analyses are from a USGS laboratory. 

The coal chemistry metadata file for Bangladesh is called “BangladeshAnalyticalData Metadata.htm.”

Stratigraphy of the Bangladesh coal-bearing sections

Figure 4 is a generalized stratigraphic column of Bangladesh (adapted from Khan and 

Muminullah, 1988). Formation names vary by area within the country but often are the same as in 

bordering areas of India.
18

Figure 4. Correlation chart of stratigraphic units in the coalfields of Bangladesh, indicating formation and group 

names.
19

Gondwana coal

The Barapukuria coalfield in the Dinajpur district of northwestern Bangladesh (Bakr and others, 

1996) is currently the only coal mine that has been developed in Bangladesh’s Gondwana coals. 

Barapukuria is an underground longwall mine and has had operational problems mostly because of

flooding from an overlying aquifer (Dupi Tila Formation). Environmental concerns have caused local 

resistance to further mining in Barapukuria and in adjacent Gondwana coalfields. The mine reported 

production of 109,098 tonnes of coal from 1 July 2008 to 30 June 2009 (Fong-Sam, 2011).

In northwestern Bangladesh, the Nawabgonj and Dangapara coalfields have unproven resources.

Coal is considered too deep for exploitation near Bogra; four other Gondwana basins in northwestern

Bangladesh with no known coal (to date) include Badargonj, Osmanpur, Burirdoba, and Shimnager 

(Muller, 2009).

The Early Permian-age Kuchma Formation contains coal (Khan and Muminullah, 1988). 

Overlying it, the Parharpur Formation hosts seven or more thick coal beds from 650 to 1,160 m deep in 

the Jamalganj coalfield of northwestern Bangladesh. Permian units in other coalfields have not been 

fully documented and are named simply “Gondwana Group.”

Tertiary coal

Early Tertiary coals in northeastern Bangladesh are similar to those that crop out in adjoining 

India. However, the coal areas appear to be much less extensive in Bangladesh, and beds may be steeply 

inclined and at depths not optimal for mining (Landis and others, 1991). The Lamakata and

Bhangarghat areas, near the border with Meghalaya, India (fig. 3), have coals in the Tura Formation, 

which is early Eocene in age (Landis and others, 1991). The approximate location of the Patiya area of 

the Chittagong district (southeastern Bangladesh) is shown in figure 3, based on a news release of the 

Bangladesh Petroleum Exploration and Production Company Limited (2009), but there is nothing else 

published regarding the coal in this area. No mapped location of the Lubachhara area in the Sylhet 

district of northeastern Bangladesh was available (Banglapedia, 2006); therefore, it is not included in the 

GIS shapefile and is not shown in figure 3. In the Rangamati district of southeast Bangladesh, very 

minor coal resources of no economic importance are believed to occur in the Miocene Boka Bill 

Formation, which is largely composed of shale, siltstone, and sandstone (Rahman and others, 1985). It 

was not deemed significant enough to show in figure 3.

Coal chemistry

The quality of Permian coals is considered to be better in Bangladesh than in India―lower in 

ash yield and lower in sulfur. Coal produced at the Barakupuria mine averages about 12 percent ash 

yield and 0.53 percent sulfur (Petrobangla, 2011). The limited data in the point file for Bangladesh 

Permian coals from five holes indicate a range of 7.63 to 67.6 percent ash yield and 0.24 to 3.15 percent 

total sulfur (both as-received basis).

Acknowledgments 

The thorough compilations of information on India coal in Bulletin 45 by the Geological Survey 

of India were indispensable to this effort, as was the interagency effort between the Coal Wing of the 

Geological Survey of India (Abhijit Mukhopadhyay and S.K. Mukhopadhyay) funded by the U.S. India 

Fund administered by the U.S. Department of State, which allowed the USGS analysis of some coal 

samples. Sohagpur basin coal petrographic analyses were provided by Peter D. Warwick. In Rajasthan, 

India, coal samples were collected by John R. SanFilipo with the assistance of K.D. Sharma, formerly of 
20

the Central Arid Zone (India) Development Authority, and the Rajasthan State Mineral Development 

Corporation; partial funding was provided by the U.S. Department of Agriculture. Petrographic analyses 

of the Rajasthan coals (Giral mine) were provided by James C. Hower and Cody D. Patrick at the 

University of Kentucky Center for Applied Energy Research in Lexington. Bangladesh cores were made 

available for analysis by the Geological Survey of Bangladesh (M. Nazrul Islam). Major-, minor-, and 

trace-element data were provided by the USGS Energy Geochemistry Laboratory and ultimate and 

proximate analyses by Commercial Testing of Somerset, Pa. Appreciation is also expressed to all earlier 

USGS researchers in India and Bangladesh: Edwin R. Landis (deceased), Peter D. Warwick, John R. 

SanFilipo, Robert M. Milici, Harold. J. Gluskoter, Neely H. Bostick, Craig J. Wandry, and William J. 

Betterton. We express appreciation for the instructive reviews by Alexander W. Karlsen, Harold J. 

Gluskoter, and Yolanda Fong-Sam of the U.S. Geological Survey, and also by Dr. Atul K. Varma of the 

Department of Geology, Indian School of Mines in Dhanbad, India.

References Cited

Arora, V., Jha, U., Bandhopadhyay, P., and Kumar, S., 2006, An investigation of the relationship 

between raw coal characteristics and effluent quality of Kedla and Rajrappa washeries; Jharkhand, 

India: Journal of Environmental Management, v. 78, p. 392–404.

Bakr, M.A., Rahman, Q.M.A., Islam, M.M., Islam, M.K., Uddin, M.N., Resan, S.A., Halder, M.J., 

Sultan-Ul-Islam, M., Ali, M.W., Chowdhury, Mokbul-E-Ala, Mannan, K.H., and Anam, A.N.M.H., 

1996, Geology and coal deposit of Barapukuria Basin, Dinajpur district, Bangladesh: Geological 

Survey of Bangladesh, v. 8, part 1, 42 p. and annex.

Bandyopadhyay, R.K., 1996, A collection of papers on the lithostratigraphy and paleoenvironment of 

some coal and lignite basins in peninsular India: Geological Survey of India, Special Publication 

No. 20, 74 p.

Bangladesh Bureau of Educational Information and Statistics (BANBEIS), 2011, Country profile, 1 p., 

accessed April 5, 2011, at http://www.banbeis.gov.bd/bd_pro.htm.

Bangladesh Petroleum Exploration and Production Company Ltd. (BAPEX), 2009, Bangladesh 

Economic News, November 7, 2009: BAPEX Web site, accessed July 26, 2011, at 

http://www.bssnews.net/newsDetails.php?cat=8&id=69137&date=2009-11-06.

Bangladesh Power Development Board, 2011, Key statistics: Bangladesh Power Development Board

Web site, accessed April 5, 2011, at http://www.bpdb.gov.bd/key_statistics.htm.

Banglapedia, 2006, Lignite: Banglapedia Web site, accessed May 4, 2011, at 

http://www.banglapedia.org/httpdocs/HT/L_0102.HTM.

Bostick, N.H., Betterton, W.J., Gluskoter, H.J., and Islam, M.N., 1991, Petrography of Permian 

“Gondwana” coals from boreholes in northwestern Bangladesh, based on semiautomated reflectance 

scanning: Organic Geochemistry, v. 17, no. 4, p. 399-413.

Chandra, D., 1992, Jharia coalfields: Bangalore, Geological Society of India, Mineral Resources of 

India, v. 5, 149 p.

Central Fuel Research Institute, Central Mine Planning and Design Institute, Ltd. (CFRI), 1993, Coal 

Atlas of India: Calcutta, India, Coal India Ltd., 129 p.

Central Fuel Research Institute, 1979, Indian coals quality evaluation data―Chirimiri, Sohagpur, Johilla 

River, Umaria, Pench-Kanhan-Tawa Valley, and Mohpani coalfields: Dhanbad, Bihar, Central Fuels 

Research Institute, v. 6, 221 p.

Dutta, Prodip, 2001, Gondwana lithostratigraphy of peninsular India: Gondwana Research, v. 5, no. 2, 

p. 540–553.
21

Energy Information Administration, 2011, International Energy Statistics for coal: Energy Information 

Administration Web site, accessed March 12, 2011, at 

http://www.eia.doe.gov/cfapps/ipdbproject/iedindex3.cfm?tid=1&pid=7&aid=1&cid=r7,&syid=2005

&eyid=2009&unit=TST.

Fong-Sam, Yolanda, 2011, The mineral industry of Bangladesh: U.S. Geological Survey 2009 Minerals 

Yearbook–Bangladesh (advance release), 5 p., accessed July 25, 2011, at 

http://minerals.usgs.gov/minerals/pubs/country/2009/myb3-2009-bg.pdf.

Fong-Sam, Yolanda, Kuo, C.S., Shi, Lin, Tse, Pui-Kwan, Wacaster, Susan, and Wilburn, D.R., 2010, 

The mineral industries of Asia and the Pacific: U.S. Geological Survey 2008 Minerals Yearbook–Asia 

and the Pacific, 25 p., accessed July 25, 2011, at http://minerals.usgs.gov/minerals/pubs/country/2008/

myb3-sum-2008-asia-pacific.pdf.

Fox, C.S., 1934 (reprinted 2001), The Lower Gondwana coalfields of India: Calcutta, India, Memoirs of 

the Geological Survey of India, v. LIX, 368 p.

Geological Survey of India, 1977, Exploration in some major coalfields of India: New Delhi, India, 

Geological Survey of India Miscellaneous Publication No. 35, 584 p., 50 pls.

Geological Survey of India, 1981, Coalfields of northeastern India, in Raja Rao, C.S., ed., Coalfields of 

India, volume I: Calcutta, India, Geological Survey of India Bulletin Series A, no. 45, 76 p., 15 pls.

Geological Survey of India, 1982, Coal resources of Tamil Nadu, Andhra Pradesh, Orissa and 

Maharashtra, in Raja Rao, C.S., ed., Coalfields of India, volume II: Calcutta, India, Geological Survey 

of India Bulletin Series A, no. 45, 103 p., 13 pls.

Geological Survey of India, 1983, Coal resources of Madhya Pradesh, Jammu and Kashmir, in Raja 

Rao, C.S., ed., Coalfields of India, volume III: Calcutta, India, Bulletin Series A, no. 45, 204 p., 

18 pls.

Geological Survey of India, 1987, Coal resources of Bihar (excluding Dhanbad district), in Raja Rao, 

C.S., ed., Coalfields of India, volume IV, Part 1: Calcutta, India, Bulletin Series A, no. 45, 336 p., 

18 pls.

Geological Survey of India, 2003, Coal resources of West Bengal, in Raja Rao, C.S., ed., Coalfields of 

India, volume V: Calcutta, India, Bulletin Series A, no. 45, 109 p., 4 pls.

Geological Survey of India, 2006, Coal resource position in India; Presented at Underground Coal 

Gasification Workshop, November 12–15, 2006, Kolkata, India, accessed April 5, 2011, at 

http://www.fossil.energy.gov/international/Publications/ucg_1106_gsi.pdf.

Ghosh, S., 2009, Electricity supply, employment and real GDP in India―Evidence from cointegration 

and Granger-causality tests: Energy Policy, v. 37, p. 2926–2929.

Ghosh, T.K., 1997, Petrography and metamorphism of the lower Gondwana (Permian) coal of the 

Rangit Valley, eastern Himalayas, India: International Journal of Coal Geology, v. 33, p. 351–368.

Gowrisankaran, S., Sethi, P.P., Hariharan, R., and Agrawal, K.P., 1987, Lignite deposits of 

India―Their occurrences, depositional features, and characteristics: Proceedings of the National 

Seminar on Coal Resources of India, p. 481–553.

Guha, D.K., Henkel, Herbert, and Imam, Badrul, 2010, Geothermal potential in Bangladesh—Results 

from investigations of abandoned deep wells: Bali, Indonesia, Proceedings of the World Geothermal 

Congress, April 25–29, 2010, 8 p.

Hearn, P.P., Jr., Hare, T.M., Schruben, P., Sherrill, D., LaMar, C., and Tsushima, P., 2001, Global GIS 

database; Digital atlas of South Asia: U.S. Geological Survey Digital Data Series 62–C, CD-ROM.

Hijmans, R.J., Guarino, Luigi, Jarvis, Andy, O’Brien, Rachel, Mathur, Prem, Bussink, Coen, Cruz, 

Mariana, Barrantes, Israel, and Rojas, Edwin: DIVA-GIS, accessed December 2010, at 

http://www.diva-gis.org/.
22

India Ministry of Home Affairs, 2011, Census of India 2001: India Ministry of Home Affairs Web site, 

accessed March 17, 2011, at http://www.censusindia.gov.in/2011-common/

CensusDataSummary.html.

International Commission on Stratigraphy, 2009, International stratigraphic chart: International 

Commission on Stratigraphy Web site, accessed April 1, 2011, at 

http://www.stratigraphy.org/upload/ISChart2009.pdf.

Islam, M.R., and Hayashi, Daigoro, 2008, Geology and coal bed methane resource potential of the 

Gondwana Barapukuria coal basin, Dinajpur, Bangladesh: International Journal of Coal Geology, v. 

75, p. 127–143.

Khan, M.R., and Muminullah, M., 1988, Stratigraphic lexicon of Bangladesh: Records of the Geological 

Survey of Bangladesh, v. 5, pt. 1, 70 p.

Krishnan, M.S., 1956, Volcanic rocks of India: Bulletin of Volcanology, v. 18, p. 125–132.

Landis, E.R, Islam, M.N., Gluskoter, H.J., Bostic, Neely, Rahman, Q.M.A., and Abdullah, S.K.M., 

1991, Contributions to coal geology of Bangladesh: U.S. Geological Survey Project Report, 

Bangladesh Investigation (IR)BG–9, 132 p.

Merrill, M.D., and Tewalt, S.J., 2008, GIS representation of coal-bearing areas in Africa: U.S. 

Geological Survey Open-File Report 2008–1258. (Also available at 

http://pubs.usgs.gov/of/2008/1258/.)

Mondal, M.A.H., Boie, W., and Denich, M., 2010, Future demand scenarios of Bangladesh power 

sector: Energy Policy, v. 38, p. 7416–7426.

Mondal, M.A.H., Mathur, J., and Denich, M., 2011, Impacts of CO2 emission constraints on technology 

selection and energy resources for power generation in Bangladesh: Energy Policy, v. 39, 

p. 2043–2050.

Mukherjee, A.K., Alam, M.M., Mazumdar, S.K., Haque, R., and Gowrisankaran, S., 1992, Physicochemical properties and petrographic characteristics of the Kapurdi lignite deposit, Barmer Basin, 

Rajasthan, India: International Journal of Coal Geology, v. 21, p. 31–44.

Muller, Mark, 2009, It's not only about coal mining―Coal-bed methane (CBM) and underground 

gasification (UCG) potential in Bangladesh: An independent technical review for Mines and 

Communities, accessed April 4, 2011, at 

http://www.accountabilityproject.org/downloads/Phulbari_CBM_Report_MRM.pdf.

Pareek, H.S., 1988, Petrographic characteristics of the solid fuels of India with particular reference to 

the coking coals: International Journal of Coal Geology, v. 10, p. 285–307.

Persits, F.M., Wandrey, C.J., Milici, R.C., and Manwar, Abdullah, comps., 1997, Digital geologic and 

geophysical data of Bangladesh: U.S. Geological Survey Open-File Report 97–470H, CD-ROM.

(Also available at http://pubs.usgs.gov/of/1997/ofr-97-470/OF97-470H/.)

Petrobangla, 2011, Barakupuria Coal Mining Company Limited (BCMCL): BCMCL Web site, accessed 

April 5, 2011, at http://www.bcmcl.org.bd/.

Rage, J.-C., Bajpai, S., Thewissen, J.G.M., and Tiwari, B.N., 2003, Early Eocene snakes from Kutch, 

western India, with a review of the Palaeophiidae: Geodiversitas, v. 25, no. 4, p. 695–716.

Rahman, Q.M.A., Mohiuddin, M.Z., and Hassan, M., 1985, Geology of the Chandraghona-Kaptai area, 

Rangamati district, Bangladesh: Dhaka, Bangladesh, Records of the Geological Survey of 

Bangladesh, v. 3, pt. 3, 12 p.

SanFilipo, J.R., Wnuk, Christopher, Fariduddin, Mohammad, Ahmed, Mujeeb, Khan, S.A., Mentab-urRahman, Chandio, A.H., and Khan, R.A., 1992, Potential for the occurrence of thick lignite deposits 

in the Thar Desert and adjacent lower Indus Plain, Sindh Province, Pakistan: U.S. Geological Survey 

Open-File Report 92–576, 131 p.
23

Sastry, M.V.A., Acharyya, S.K., Shah, S.C., Satsangi, P.P., Ghosh, S.C., Raha, P.K., Singh, Gopal, and 

Ghosh, R.N., comps., 1977, Stratigraphic lexicon of Gondwana formations of India: New Dehli, 

Geological Survey of India, Miscellaneous Publication No. 36, 170 p.

Sharma, K.D., Kumar, P., Gough, L.P., and SanFilipo, J.R., 2004, Rehabilitation of a lignite minedisturbed area in the Indian Desert: Land Degradation and Development, v. 15, p. 163–176.

Singh, M.P., and Singh, G.P., 1995, Petrological evolution of the Paleogene coal deposits of Jammu, 

Jammu and Kashmir, India: International Journal of Coal Geology, v. 27, p. 171–199.

Singh, P.K., Singh, M.P., and Singh, A.K., 2010, Petrochemical characterization and evolution of the 

Vastan lignite, Gujarat, India: International Journal of Coal Geology, v. 82, p. 1–16.

Tewalt, S.J., Kinney, S.A, and Merrill, M.D., 2008, GIS representation of coal-bearing areas in North, 

Central, and South America: U.S. Geological Survey Open-File Report 2008–1257. (Available online 

at http://pubs.usgs.gov/of/2008/1257/.)

Tewalt, S.J., Belkin, H.E., SanFilipo, J.R., Merrill, M.D., Palmer, C.A., Warwick, P.D., Karlsen, A.W., 

Finkelman, R.B., and Park, A.J., comps., 2010, Chemical analyses in the World Coal Quality 

Inventory, version 1: U.S. Geological Survey Open-File Report 2010–1196, 4 p. (Also available at

http://pubs.usgs.gov/of/2010/1196/.)

U.S. Geological Survey, 2010, Divisions of geologic time; Major chronostratigraphic and 

geochronologic units: U.S. Geological Survey Fact Sheet 2010–3059, 2 p. (Also available at 

http://pubs.usgs.gov/fs/2010/3059.)

U.S. Geological Survey–Bangladesh Gas Assessment Team, 2001, U.S. Geological Survey-PetroBangla 

cooperative assessment of undiscovered natural gas resources of Bangladesh, in Wandrey, C.J., ed., 

Petroleum systems and related geologic studies in Region 8, south Asia: U.S. Geological Survey 

Bulletin 2208–A, 119 p. (Also available at http://pubs.usgs.gov/bul/b2208-a/b2208-a.pdf.)

U.S. Department of State, 2011, restricted U.S. Department of State Web site, accessed April 2010, at 

https://www.intelink.gov.

World Energy Council, 2010, World Energy Insight 2010: 21st World Energy Congress report, accessed 

August 5, 2011, at http://www.worldenergy.org/documents/wec_combined.pdf.