U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2011–3154

January 2012

Using a geology-based assessment methodology, the U.S. Geological Survey estimated volumes of undiscovered, technically 

recoverable, conventional petroleum resources for the Amu Darya Basin and Afghan–Tajik Basin Provinces of Afghanistan, Iran, 

Tajikistan, Turkmenistan, and Uzbekistan. The mean volumes were estimated at 962 million barrels of crude oil, 52 trillion cubic 

feet of natural gas, and 582 million barrels of natural gas liquids for the Amu Darya Basin Province and at 946 million barrels of 

crude oil, 7 trillion cubic feet of natural gas, and 85 million barrels of natural gas liquids for the Afghan–Tajik Basin Province.

World Petroleum Resources Project

Assessment of Undiscovered Oil and Gas Resources of the Amu 

Darya Basin and Afghan–Tajik Basin Provinces, Afghanistan, Iran, 

Tajikistan, Turkmenistan, and Uzbekistan, 2011

Introduction

The U.S. Geological Survey (USGS) estimated volumes 

of undiscovered technically recoverable, conventional oil 

and gas resources of the Amu Darya Basin Province and the 

Afghan–Tajik Basin Province in Afghanistan, Iran, Tajikistan, 

Turkmenistan, and Uzbekistan, in south-central Asia (fig. 1). 

The assessment is part of a program to estimate petroleum 

resources for priority basins around the world, specifically 

for total petroleum systems (TPS) and assessment units (AU) 

that are defined by their geologic attributes that are favorable 

for the generation and accumulation of petroleum. The Amu 

Darya Basin Province encompasses more than 417,000 square 

kilometers and the Afghan–Tajik Basin Province encompasses 

more than 97,000 square kilometers. This assessment was based 

on published geologic information and on commercial data 

from oil and gas wells and fields, and field production records.

Total Petroleum Systems and Assessment Units

Both the Amu Darya and Afghan–

Tajik Basins are interpreted to have 

originated as rift/sag basins (Ulmishek, 

2004), which controlled the distribution 

of Mesozoic and Paleogene source 

rocks as well as oil and gas resources 

in the respective geologic provinces. 

The basins underwent compression and 

deformation during the late Paleogene 

through Neogene collision of India with 

the Eurasian continent. The greatest 

amount of deformation occurred in the 

Afghan–Tajik Basin Province because 

it is closer to the collision zone.

Figure 1. Generalized map showing the 

boundaries of the Amu Darya Basin and 

Afghan-Tajik Basin geologic provinces, 

centerpoints of oil and gas fields, and 

the location of geologic cross section 

A−A′ shown in figure 2. Field data from 

IHS Energy (2009); geologic province 

boundaries from Persits and others (1998) 

and Klett and others (2006); base map from 

Environmental Systems Research Institute, 

Inc. (ESRI), 2010, ArcGIS Online Services– 

Ready-to-Use Content on Demand 

(http://www.esri.com/software/arcgis/

arcgisonline/index.html).

!

!

!

!

!!!

!

! !

!! ! !

! !

!

! ! ! !

! !

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!!

!

!

!

! !

!

!

!

!

!!

!

!

!

!

!!

!

!

! !

!

!

!

!

!

!

! !

!

!

!

!

!

! ! !

!

!

!

!

!

!

! ! !

!

!

!

! ! !

!

!

!

!

!

!

!

!

!

!

!

!

!

! !

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!!

!

!

!

! !

!

!

!

!

!

!

!

!

!

! ! !

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

! !

! !

!

!

!

!

!!!

!

!

!

!

!

!

!

!

!

!! !!

!

! ! ! !

!

!

!

!

!

!

!

!

!

!

!

!

!

!

! !! !!!!!!! !!!

! !

! !

!!

!

!

!

!

! ! ! !! !

! !

!

!

!!

!

!

! !

!

!

!!

!! !

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!!

!

! !

!

! !

!

!

! !

!

!

!

! !

!

!

!

!

!

!

!!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

! !

!

!

!

!

!

!

!

!

!

!

!!

!

!

!

!

!

!!

!

! !

! !!

!

!

!!!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

! !

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

! ! !

!

!

! ! !

!

!

!

!

!

!

! !

!

!

!

!

!

! !

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!

!!!

!

!

!

!

!

!

!

!

!

!

! !

!

!

!

!

!

! ! !

!

!

!

!

! !

!

!

!

!

!

! !

!

!

!

!

!

!

!

!

!

!

0 100 200 300 400 500 KILOMETERS

0 100 200 300 MILES

Kabul

35o

40o

55o 60o 65o 70o

Amu Darya Basin

NORTHERN AND

WESTERN AREAS MURGAB DEPRESSION

SUPRASALT

AND SUBSALT

IRAN

UZBEKISTAN

TURKMENISTAN

AFGHANISTAN

Dushanbe

Tashkent

Ashkhabad

Afghan-Tajik Basin

EASTERN

THRUSTS, FOLDS,

AND SUBSALT

WESTERN

GENTLE

FOLDS

AND

SUBSALT

North Afghan High

Coalbed Gas

Province boundary

Assessment unit boundary

Country boundary

Oil field

Gas field

City

EXPLANATION

A'

Location of cross section

KARABIL-BADKHYZ

(SOUTHERN AREA)

A

!

!
source rocks was probably reached in Cretaceous to Paleogene 

time when the greatest amount of sediment was deposited. 

Paleogene source rocks at present are in the oil-generation 

window, having matured in the late Paleogene and Neogene 

by loading of thrust sheets that formed by collisional deformation. In the Amu Darya Basin Province, most known recoverable crude oil and natural gas were discovered in Jurassic 

clastic rocks, Jurassic carbonate reef- and platform-associated 

rocks, and Cretaceous clastic rocks (down to a depth of about 

5,500 meters) (Klett and others, 2006). Most known recoverable crude oil and natural gas in the Afghan−Tajik Basin 

Province have been discovered in Upper Cretaceous carbonate 

rocks and in Paleogene clastic rocks (down to a depth of about 

3,700 meters) (Klett and others, 2006). The regional seal rock 

is a thick Upper Jurassic evaporite section; other seal rocks 

include Jurassic, Cretaceous, and Paleogene intraformational 

shales. Identified traps include reactivated rift-related basement structures, compressional structures formed by Cenozoic 

deformation, fault-related structures, updip depositional-facies 

changes, updip depositional and erosional pinchouts, and various reef- and carbonate-platform-associated facies. The future 

potential for undiscovered conventional oil and gas accumulations is in structures and various reef and carbonate-platform 

facies beneath the Upper Jurassic evaporite section, which 

previously have not been fully exploited. High potential exists 

in Upper Jurassic slope and basin gravity-flow deposits in the 

subsalt section.

One TPS was defined that spans the Amu Darya Basin 

and Afghan–Tajik Basin Provinces (table 1). The Mesozoic–

Cenozoic Composite TPS is defined by petroleum source rocks 

ranging in age from Jurassic through Paleogene. Four AUs containing conventional undiscovered oil and gas resources were 

defined geologically within the Amu Darya Basin Province: 

(1) Northern and Western Areas, (2) Karabil−Badkhyz (Southern Area), (3) Murgab Depression Suprasalt, and (4) Murgab 

Depression Subsalt (figs. 1, 2). Two AUs containing conventional undiscovered oil and gas resources were defined geologically within the Afghan–Tajik Basin Province: (1) Western 

Gentle Folds and Subsalt, and (2) Eastern Thrusts, Folds, and 

Subsalt (fig. 1). Other AUs that possibly contain continuous 

accumulations also were identified based on the geochemical 

and physical properties of the source rocks, but these AUs were 

not quantitatively assessed in this study.

Major source rocks in both the Amu Darya Basin and 

Afghan–Tajik Basin Provinces are mudstones within the 

Lower–Middle Jurassic carbonaceous shales and coal and 

Upper Jurassic restricted-marine shale (Klett and others, 

2006). Paleogene (Eocene) marine, or possibly lacustrine, 

shale is another source rock, but it is only present in the 

Afghan–Tajik Basin Province (Klett and others, 2006). Jurassic source rocks, at present, are in the gas-generation window 

throughout much of the Amu Darya and Afghan–Tajik Basins, 

except along the margins of the basins, where they are in the 

oil-generation window or immature. Maturation of Jurassic 

Figure 2. Geologic cross section for the Amu Darya Basin. See figure 1 for location. 

Approximate length of cross section is 275 kilometers. Modified from Aleshina and 

Bluket (1967).

5.0

MAIMANA

STEP

NORTH KARABIL

DEPRESSION

SOUTH KARABIL

NW HIGH SE

Kilometers (Datum Mean Sea Level)

A A'

Cretaceous

EXPLANATION

Fault

Stratigraphic

boundary

0

–2.0

10.0

5.0

0

–2.0

10.0 Basement

?

Inferred fault

Upper Jurassic

Lower-Middle

Jurassic

Permian-Triassic

Paleogene

Neogene-Quaternary

Basement
Assessment Results

Estimates of volumes of undiscovered technically recoverable, conventional oil and gas resources are shown in table 1. 

No attempt was made to estimate economically recoverable 

resources because it is beyond the scope of this study. In 

summary, the estimated mean volumes of undiscovered, 

technically recoverable, conventional oil and gas resources for 

the Amu Darya Basin Province are about 962 million barrels 

(MMB) of crude oil, 52,025 billion cubic feet (BCF) of natural gas (2,321 BCF of associated and dissolved natural gas, 

and 49,704 BCF of nonassociated natural gas), and 582 MMB 

of natural gas liquids (55 MMB of natural gas liquids in oil 

accumulations and 527 MMB of total liquids in nonassociated 

gas accumulations). The estimated mean volumes of undiscovered, technically recoverable, conventional oil and gas resources 

for the Afghan–Tajik Basin Province are about 946 MMB of 

crude oil, 7,072 BCF of natural gas (225 BCF of associated and 

dissolved natural gas and 6,847 BCF of nonassociated natural 

gas), and 85 MMB of natural gas liquids (4 MMB of natural 

gas liquids in oil accumulations and 81 MMB of total liquids in 

nonassociated gas accumulations).

Table 1. Amu Darya Basin and Afghan−Tajik Basin Provinces assessment results (undiscovered, technically recoverable, 

conventional resources).

[MMB, million barrels; BCF, billion cubic feet. Results shown are fully risked estimates. For gas fields, all liquids are included under the natural gas liquids 

(NGL) category. F95 denotes a 95-percent chance of at least the amount tabulated. Other fractiles are defined similarly. Fractiles are additive under the 

assumption of perfect positive correlation. TPS, total petroleum system; AU, assessment unit. Gray shading indicates not applicable].

Total undiscovered resources Total petroleum systems

(TPS)

and assessment units (AU)

Field

type

Oil (MMB) Gas (BCF) NGL (MMB)

F95 F50 F5 Mean F95 F50 F5 Mean F95 F50 F5 Mean

Mean (expected)

largest

field size

(MMB or BCF)

Gas

Northern and Western Oil

Areas AU

Amu Darya Basin Province, Mesozoic–Cenozoic Composite TPS

145 215 315 221 267 427 661 441 1 1 2 1

5,551 8,153 11,832 8,344 39 58 86 60

12

238

Gas

Oil Western Gentle Folds and

Subsalt AU

44 96 2

5,509 65

27 43 66 54 92 149 1 2 3

2,962 5,271 8,887 33 61 109

8

914

Afghan–Tajik Basin Province, Mesozoic–Cenozoic Composite TPS

Gas

Oil Karabil-Badkhyz

(Southern Area) AU

65 108 171 112 165 275 443 286 <1 1 1 1

2,311 3,762 5,832 3,877 15 25 40 26

18

429

Gas

Murgab Depression Oil

Suprasalt AU

5 12 41 16 11 34 129 48 <1 1 4 2

1,151 1,894 2,961 1,953 13 22 36 23

10

238

Gas

Murgab Depression Oil

Subsalt AU

384 597 899 613 924 1,495 2,341 1,546 30 49 79 51

21,735 34,564 52,539 35,530 249 406 632 418

49

2,938

Total undiscovered petroleum

resources 962 52,025 582

Total undiscovered petroleum

resources 946 7,072 85

Gas

Oil Eastern Thrusts, Folds, and

Subsalt AU

902 129 2

1,338 16

599 881 1,282 81 126 191 1 2 3

857 1,306 1,936 10 15 23

24

100
For Further Information

Supporting geologic studies of total petroleum systems and 

assessment units, and reports on the methodology used in the 

assessment of the Amu Darya Basin and Afghan–Tajik Basin 

Provinces, as well as the assessment results, are available at the 

USGS Energy website: http://energy.usgs.gov.

Amu Darya Basin and Afghan–Tajik Basin Provinces 

Assessment Team

T.R. Klett (tklett@usgs.gov), Christopher J. Schenk, Craig J. 

Wandrey, Ronald R. Charpentier, Michael E. Brownfield, 

Janet K. Pitman, Richard M. Pollastro, Troy A. Cook, and 

Marilyn E. Tennyson.

References Cited

Aleshina, Z.I., and Bluket, O.A., 1967, Yuzhnaya i yugovostochnaya okrainy Murgabskoy vpadiny; novaya perspektivnaya neftegazonosnaya oblast’ Turanskoy plity (South 

and southeast margin of the Murgab basin — new petroleum–

potential region of the Turan plate, in Varentsev, M.I., ed., 

Tektonika neftegazonosnykh vpadin Sredney Azii i Kazakhstana (Tectonic control of oil and gas in middle Asia and 

Kazakhstan): Moscow, Nauka, p. 109−115.

IHS Energy, 2009 [includes data current through October 2009], 

International exploration and production database: Englewood, Colo., IHS Energy.

Klett, T.R., Ulmishek, G.F., Wandrey, C.J., Agena, W.F., and 

the U.S. Geological Survey−Afghanistan Ministry of Mines 

and Industry Joint Oil and Gas Resource Assessment Team: 

Amirzada, A., Selab, A., Muty, S.A., Nakshband, H.G., 

Wardak, M.G., Aminulah, Wahab, A., Taylor, D.J., Hill, R.J., 

Pribil, M., King, J.D., Pawlewicz, M.J., Barker, C.E., Ahlbrandt, T.S., Charpentier, R.R., Pollastro, R.M., and Schenk, 

C.J., 2006, Assessment of undiscovered technically recoverable conventional petroleum resources of northern Afghanistan: U.S. Geological Survey Open-File Report 2006−1253, 

1 CD−ROM. (http://pubs.usgs.gov/of/2006/1253/).

Persits, F.M., Ulmishek, G.F., and Steinshouer, D.W., 1998, 

Map showing geology, oil and gas fields, and geologic provinces of the former Soviet Union: U.S. Geological Survey 

Open-File Report 97–470E, CD–ROM.

Steinshouer, D.W., Klett, T.R., Ulmishek, G.F., Wandrey, 

C.J., Wahl, R.R., Hill, R.J., Pribil, M., Pawlewicz, M.J., 

King, J.D., Agena, W.F., Taylor, D.J., Amirzada, A., Selab, 

A., Mutteh, A-S., Haidari, G.N., and Wardak, M.G., 2006, 

Petroleum resource potential GIS of northern Afghanistan, 

2006: U.S. Geological Survey Open-File Report 2006−1179, 

1 CD−ROM. (http://pubs.usgs.gov/of/2006/1179/).

Ulmishek, G.F., 2004, Petroleum geology and resources of the 

Amu-Darya Basin, Turkmenistan, Uzbekistan, Afghanistan, 

and Iran: U.S. Geological Survey Bulletin 2201-H, 32 p.