Petroleum Geology of Libya

391 Pages·2016·81.356 MB·English

by  Don Hallett, Daniel Clark-Lowes

PETROLEUM GEOLOGY
OF LIBYA
SECOND EDITION
PETROLEUM
GEOLOGY OF
LIBYA
SECOND EDITION
D H
on allett
D C -l
aniel lark owes
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List of Figures
Fig. 1.1 Libya: The Four Principal Basins. 3
Fig. 1.2 Concession Map 1955–60. 6
Fig. 1.3 Number of Wildcat Exploration Wells Drilled Per Year. 7
Fig. 1.4 Oil Discoveries Per Year. 9
Fig. 1.5 Original Recoverable Oil Reserves Discovered by Year. 10
Fig. 1.6 Wildcat Exploration Wells vs Oil Discoveries Per Year. 11
Fig. 1.7 Ghadamis Basin Oil and Gas Fields. 13
Fig. 1.8 Sirt Basin Oil and Gas Fields. 14
Fig. 1.9 Oil Production by Year. 15
Fig. 1.10 Oil Price by Year. 18
Fig. 1.11 North-Western Offshore Oil and Gas Fields. 20
Fig. 1.12 Giant Oil Fields. 21
Fig. 1.13 Murzuq Basin Oil and Gas Fields. 24
Fig. 1.14 Cumulative Original Recoverable Reserves. 26
Fig. 1.15 Cumulative Original Recoverable Reserves vs Oil Production. 27
Fig. 1.16 Concessions Map, 2014. 30
Fig. 2.1 Africa, Tectonic Elements. 36
Fig. 2.2 The Rodinia Super-Continent. 37
Fig. 2.3 The Pannotia Super-Continent. 38
Fig. 2.4 The Saharan Metacraton. 39
Fig. 2.5 Basement Terranes in Libya. 41
Fig. 2.6 Gondwana in the Early Ordovician. 42
Fig. 2.7 Plate Movements in the Early Silurian. 43
Fig. 2.8 Plate Movements in the Early Devonian. 44
Fig. 2.9 Plate Movements in the Early Carboniferous. 45
Fig. 2.10 Pangaea. 46
Fig. 2.11 The Tethys Ocean. 47
Fig. 2.12 Apulia. 48
Fig. 2.13 Closure of the Tethys Ocean. 50
Fig. 2.14 Mediterranean. 51
Fig. 2.15 Summary Chart of Plate Tectonic Events. 52
Fig. 3.1 Kufrah Basin, Lithostratigraphic Chart. 57
Fig. 3.2 Kufrah Basin, Chronostratigraphic Framework. 59
Fig. 3.3 Kufrah Basin, Cambro-Ordovician Isopach Map. 60
Fig. 3.4 Kufrah Basin, Devonian Isopach Map. 63
Fig. 3.5 Murzuq Basin, Lithostratigraphic Chart. 66
Fig. 3.6 Murzuq Basin, Hasawnah Formation Isopach Map. 70
Fig. 3.7 Murzuq Basin, Mamuniyat Formation Isopach Map. 72
Fig. 3.8 Murzuq Basin, Tanzuft Formation Isopach Map. 74
Fig. 3.9 Murzuq Basin, Total Devonian Isopach Map. 77
Fig. 3.10 Murzuq Basin, Carboniferous Isopach Map. 80
Fig. 3.11 West Libya Time Stratigraphic Chart. 83
Fig. 3.12 West Libya, Schematic Chronostratigraphic Framework. 86
Fig. 3.13 Ghadamis Basin, Tanzuft Formation Isopach Map. 88
Fig. 3.14 Ghadamis Basin, Akakus Formation (Late Silurian) Isopach Map. 90
Fig. 3.15 Ghadamis Basin, Tadrart Formation (Early Devonian) Isopach Map. 91
Fig. 3.16 Ghadamis Basin, Kurrush (Ra’s Hamia) Formation (Mid-Triassic) Isopach Map. 96
Fig. 3.17 Libyan North-Western Offshore, Time Stratigraphic Summary Chart. 100
Fig. 3.18 Libyan North-Western Offshore, Schematic Chronostratigraphic Framework. 102
Fig. 3.19 Libyan North-Western Offshore, Eocene Nummulitic Trend. 103
Fig. 3.20 Libyan North-Western Offshore, Cartoon of Lower Eocene Facies. 109
Fig. 3.21 Sirt Basin Simplified Time Stratigraphic Summary Chart. 113
Fig. 3.22 Sirt Basin Schematic West–East Chronostratigraphic Cross Section. 114
Fig. 3.23 Sirt Basin Schematic South–North Chronostratigraphic Cross Section. 115
Fig. 3.24 Libya, Distribution of the Nubian Group. 116
Fig. 3.25 Eastern Sirt Basin, Depositional Model for Sarir Formation. 118
vii
viii LIST OF FIGURES
Fig. 3.26 Eastern Sirt Basin, Nubian Group Isopach Map. 120
Fig. 3.27 Eastern Sirt Basin, Distribution of the Amal and Maragh Formations. 122
Fig. 3.28 Eastern Sirt Basin, Distribution of the Taqrifat Formation. 125
Fig. 3.29 Central Sirt Basin, Wahah Formation Palaeogeography. 127
Fig. 3.30 Central Sirt Basin, Wahah Formation Cross Section, Raqubah Field. 128
Fig. 3.31 Sirt Basin, Simplified Time Stratigraphic Summary Chart of the Palaeogene. 129
Fig. 3.32 Sirt Basin, Palaeogeography of the Palaeocene Carbonates. 130
Fig. 3.33 Central Sirt Basin, Early Palaeocene Hagfah Formation Isopach Map. 131
Fig. 3.34 Central Sirt Basin, Intisar Embayment, West to East Schematic Chronostratigraphic Cross-Section. 132
Fig. 3.35 Central Sirt Basin, Intisar Embayment, Late Palaeocene Palaeogeography. 135
Fig. 3.36 Sirt Basin, Distribution of the Ypresian Formations and Facies. 137
Fig. 3.37 Eastern Sirt Bain, Jalu Formation Isopach Map and Overlying Seal. 139
Fig. 3.38 Eastern Sirt Basin, Chadra Member Palaeogeographic Map. 140
Fig. 3.39 Cyrenaica, Well Location Map. 142
Fig. 3.40 Cyrenaica, Pre-Hercynian Subcrop Map. 145
Fig. 3.41 Cyrenaica, Triassic-Jurassic Facies Map. 146
Fig. 3.42 Cyrenaica, Simplified Stratigraphic Summary Chart (Late Jurassic to Miocene). 147
Fig. 3.43 Cyrenaica, Late Jurassic-Early Cretaceous Palaeogeographic Map. 148
Fig. 3.44 Cyrenaica, Late Albian-Early Cenomanian Palaeogeographic Map. 149
Fig. 3.45 Cyrenaica, Cenomanian to Campanian Palaeogeographic Map. 150
Fig. 3.46 Cyrenaica, Early Eocene Palaeogeographic Map. 151
Fig. 3.47 Cyrenaica, Mid-Eocene Palaeogeographic Map. 152
Fig. 3.48 Cyrenaica, Late Eocene Palaeogeographic Map. 152
Fig. 4.1 Libya Tectonic Elements. 162
Fig. 4.2 Hercynian Unconformity Subcrop Map. 164
Fig. 4.3 Kufrah Basin, Top Basement Structure Map. 165
Fig. 4.4 Kufrah Basin W–E Cross Section. 166
Fig. 4.5 Kufrah Basin N–S Cross Section. 167
Fig. 4.6 Murzuq Basin Top Ordovician Structure Map. 172
Fig. 4.7 Murzuq Basin W–E Cross Section. 173
Fig. 4.8 Tihimboka and Qarqaf Arch Pinchout Cross Sections. 175
Fig. 4.9 Ghadamis Basin Top Tadrart/Akakus Structure Map. 177
Fig. 4.10 Ghadamis Basin N–S Cross Section. 178
Fig. 4.11 Ghadamis Basin W–E Cross Section. 179
Fig. 4.12 Nafusah Arch–Jifarah Terrace S–N Cross Section. 181
Fig. 4.13 Sirt Basin Top Cretaceous Regional Structure Map. 182
Fig. 4.14 Sirt Basin W–E Regional Cross Section. 184
Fig. 4.15 Zallah Trough Top Zahrah Formation (Thanetian) Structure Map. 186
Fig. 4.16 Zallah Trough W–E Cross Section. 187
Fig. 4.17 Abu Tumayam Trough Top Bayda Formation (Selandian) Structure Map. 189
Fig. 4.18 Abu Tumayam Trough W–E Cross Section. 190
Fig. 4.19 Zahrah–Hufrah Platform Top Zahrah Formation (Thanetian) Structure Map. 191
Fig. 4.20 Zahrah–Hufrah Platform W–E Cross Section. 192
Fig. 4.21 Bayda Platform Top Bayda Formation (Selandian) Structure Map. 193
Fig. 4.22 Bayda Platform W–E Cross Section. 194
Fig. 4.23 Maradah Trough, Jahamah Platform, Zaltan Platform Top Cretaceous Structure Map. 196
Fig. 4.24 Maradah Trough, Zaltan Platform Cross Section. 197
Fig. 4.25 Ajdabiya Trough Top Cretaceous Structure Map. 200
Fig. 4.26 Ajdabiya Trough W–E Cross Section. 201
Fig. 4.27 Eastern Embayment Top Nubian Group Structure Map. 203
Fig. 4.28 Eastern Embayment N–S Cross Section. 204
Fig. 4.29 Amal Platform, Maragh Trough Top Cretaceous Structure Map. 206
Fig. 4.30 Amal Platform, Maragh Trough SW–NE Cross Section. 207
Fig. 4.31 Cyrenaica Platform, Jabal al Akhdar Uplift Top Cretaceous Structure Map. 209
Fig. 4.32 Cyrenaica Platform and Jabal al Akhdar Uplift NW–SE Cross Section. 211
Fig. 4.33 Sabratah Basin Top Jdeir Formation (Ypresian) Structure Map. 213
Fig. 4.34 Sabratah Basin S–N Cross Section. 214
Fig. 4.35 Offshore Sirt Embayment Top Mesozoic Time Structure Map. 216
Fig. 4.36 Offshore Sirt Embayment S–N Cross Section. 217
Fig. 4.37 Offshore Ajdabiya Trough Cross Section. 218
Fig. 4.38 Libya Eastern Offshore Tectonic Elements Map. 219
Fig. 4.39 Offshore Darnah Trough Time Structure Map Top Cretaceous. 221
Fig. 4.40 Offshore Darnah Trough S–N Cross Section. 222
Fig. 5.1 Principal Geochemical Indicators. 230
Fig. 5.2 Model for Silurian Hot Shale Distribution in North Africa. 232
Fig. 5.3 Generalised Distribution of Silurian Tanzuft Shale and Hot Shale Thickness, Murzuq Basin. 233
LIST OF FIGURES ix
Fig. 5.4 Relationship Between Silurian Graptolite Zonation and Basal Silurian Hot Shale. 235
Fig. 5.5 Distribution of Silurian Tanzuft Shale and Hot Shale Thickness, Greater Ghadamis Basin. 236
Fig. 5.6 Frasnian Source Rock, Distribution and Maturity, Greater Ghadamis Basin. 238
Fig. 5.7 Depth to Basement and Tanzuft Facies, Al Kufrah Basin. 239
Fig. 5.8 Distribution and Thickness of Effective Sirt Shale Source Rock, Sirt Basin. 241
Fig. 5.9 Sirt Shale Source Rock, Maturity and Source Kitchens, Sirt Basin. 242
Fig. 5.10 Pre-Sirt Shale Source Rocks and Source Kitchens, Sirt Basin. 243
Fig. 5.11 Oil Families of the Eastern Sirt Basin. 244
Fig. 5.12 Eocene and Pre-Eocene Source Rocks, Sabratah Basin. 247
Fig. 5.13 Source Rock Potential, Cyrenaica. 249
Fig. 6.1 Petroleum Systems of Libya (Oil). 254
Fig. 6.2 Petroleum Systems of Libya (Gas). 256
Fig. 6.3 Sirt Basin, Eastern Embayment, Middle Sarir Sandstone Play Fairway. 260
Fig. 6.4 Sirt Basin, Eastern Embayment, Upper Sarir Sandstone Distribution. 261
Fig. 6.5 Sirt Basin, Eastern Embayment, Schematic Cross Section Illustrating Lateral Charge to Sarir Sandstone Fields. 262
Fig. 6.6 Sirt Basin, Eastern Embayment, Stratigraphic Correlation of Sarir Sandstone. 263
Fig. 6.7 Sirt Basin, Eastern Embayment, Cross Section Through Raml Main Field. 266
Fig. 6.8 Sirt Basin, Maastrichtian Play Fairways. 267
Fig. 6.9 Sirt Basin, Migration Pathways From Ajdabiya Trough. 268
Fig. 6.10 Sirt Basin, Wahah Play Migration Pathways. 270
Fig. 6.11 Sirt Basin, Zaltan/Upper Sabil Limestone Play Fairway. 271
Fig. 6.12 Sirt Basin, Zaltan Platform, Schematic Cross Section Illustrating Charge to Palaeocene and Cambro-Ordovician Reservoirs. 272
Fig. 6.13 Sirt Basin, Jalu Play Fairway. 274
Fig. 6.14 Sirt Basin, Jalu Play Migration Pathways. 275
Fig. 6.15 Sirt Basin, Ajdabiya Trough, Burial Model. 276
Fig. 6.16 Sirt Basin, Zallah Trough, Migration Pathways. 278
Fig. 6.17 Sirt Basin, Zahrah-Hufrah Platform, Limit of Palaeocene Carbonate Reservoirs. 280
Fig. 6.18 Sirt Basin, Zahrah-Hufrah Platform, Migration Pathways. 281
Fig. 6.19 Murzuq and Greater Ghadamis, Late Ordovician Play Fairway. 284
Fig. 6.20 Murzuq Basin, Late Ordovician Stratigraphic Architecture. 286
Fig. 6.21 Murzuq Basin, Source Kitchens. 287
Fig. 6.22 Greater Ghadamis Basin, Akakus Play Fairway. 289
Fig. 6.23 Ghadamis Basin, Schematic Cross Section Illustrating Charge to Palaeozoic Clastic Reservoirs. 290
Fig. 6.24 Ghadamis Basin, Burial Model. 292
Fig. 6.25 Sabratah Basin, Eocene (Ypresian) Play Fairway. 295
Fig. 6.26 Sabratah Basin, Migration Pathways. 297
Fig. 6.27 Sabratah Basin, Makhbaz/Bahloul Gas Play. 298
Fig. 6.28 Offshore Sirt, Geo-Seismic Cross Section Across the Sirt Trough. 300
Fig. 6.29 Offshore Sirt, Schematic Cross Section Illustrating Potential Charge Scenarios. 302
Fig. 6.30 Offshore Sirt, Eocene (Lutetian) Play. 303
Fig. 6.31 Offshore Sirt, Eocene (Lutetian) Reservoir Depositional Model. 304
Fig. 7.1 Location of Oil and Gas Fields Described in this Chapter. 308
Fig. 7.2 Table of Oil Fields with originally recoverable reserves (ORR) Greater than 500 MMB. 308
Fig. 7.3 Table of Gas Fields with ORR Greater than 1 TCF. 309
Fig. 7.4 Sarir Field. 310
Fig. 7.5 Messlah Field. 311
Fig. 7.6 Jalu Field. 313
Fig. 7.7 Nasser Field. 315
Fig. 7.8 Awjilah-Nafurah Field. 316
Fig. 7.9 Intisar D Field. 318
Fig. 7.10 Raqubah Field. 320
Fig. 7.11 Zahrah-Hufrah Field. 321
Fig. 7.12 Sabah Field. 323
Fig. 7.13 Shararah A Field. 325
Fig. 7.14 El Feel (Elephant) Field. 326
Fig. 7.15 Al Wafaa Field. 328
Fig. 7.16 Hamra Field. 329
Fig. 7.17 Bouri Field. 330
Fig. 7.18 Bahr Essalam Field. 332
Fig. 8.1 Components of Ultimate Potential. 336
Fig. 8.2 Libyan Oilfields With Oil Originally in Place (OOIP) of Over 1 Billion Barrels. 337
Fig. 8.3 Map of Selected Areas of Remaining Exploration Potential. 338
Fig. 8.4 Methods of Estimating Yet-to-Find Reserves. 344
Fig. 8.5 Illustration of (A) Creaming Curve and (B) Parabolic Fractals. 345
Fig. 8.6 Libyan Oilfields Ranked by Remaining Recoverable Reserves. 347
Preface to the Second Edition
When we were invited by Elsevier to produce a sec- debt of gratitude is due to our draftsman Bob Needham
ond edition of Petroleum Geology of Libya, we assumed whose skill and professionalism are so well displayed
it would be a relatively simple task. With two authors throughout this book.
instead of one, and with access to the extensive database We also wish to thank Louisa Hutchins, Marisa
of Nubian Consulting Ltd, and with the further attrac- LaFleur, Tasha Frank and Punitha Govindaradjane at
tion of being able to use colour illustrations it seemed Elsevier for bearing with the repeated delays and for
an appealing proposition. The project turned out to be guiding the book through the preparation and pro-
much more onerous than we had anticipated. About duction stages. Amongst our colleagues at Nubian
500 technical articles on the petroleum geology of Libya Consulting we wish to thank Jon Basell, Pedro Martinez
have appeared in the 14 years since the first edition. An Duran, Johannes Sobotzki, Simon Adams and Naveen
enormous amount of new information on the Kufrah, Anandakumar for their help in maintaining, operating
Murzuq, Cyrenaica and offshore areas has become avail- and updating the database, and to Julie Richardson and
able, sequence stratigraphy has transformed the way Johannes Sobotzki for their contributions to Chapters 5
we think about the sedimentary succession, and many and 7, respectively. Our thanks also to David Boote, Nick
new exploration concepts have emerged. This has ren- Blake, Bindra Thusu, Sebastian Luning and Mustafa
dered much of the first edition obsolete and has led to Salem for providing information and advice, and to
a major re-write of large sections of the book. Murphy's our present and former Libyan colleagues for valuable
laws inevitably played their part, but eventually we technical discussions extending over many years. We
reached our objective of producing an updated survey wish to thank Hassan Hassan (BP) and Robert Kohazy
of the petroleum geology of Libya within the confines of (OMV) for their comments on sections of text and some
a single volume which we hope will help oil companies, of the illustrations, and Michael McKimm and Wendy
investment advisors, academics and others to obtain an Cawthorne at the Geological Society Library for provid-
informed overview of the subject. ing extended loan facilities on a number of key publi-
There have been some changes in the organisation of the cations and access to the Georef and Athens reference
contents. We have opted to present stratigraphy as a sin- systems. And finally we should like to thank our wives
gle chapter, and to rearrange the material by basin. A new Irina and Rosemary for their stoic acceptance of living
chapter has been added to describe and illustrate examples for more than two years under the shadow of ‘the book.’
of 15 major oil and gas fields, and the final chapter on re- There have of course been major changes in Libya
maining potential has been expanded and updated. New during the past 14 years, most notably the overthrow
material has been added on the offshore areas and on oil of the Qadafi regime in 2011 and the subsequent civil
and gas reserves. Where a basin extends into an adjacent war. Not surprisingly there has been a great decline in
country, as with the Ghadamis Basin into Algeria and the both exploration and production activity, yet despite
Sabratah Basin into Tunisia, an attempt has been made to all the problems exploration and production wells are
incorporate data on the entire basin for the sake of com- still being drilled and oil and gas are being produced.
pleteness. We have also taken the opportunity to change The lesson of history is that eventually all situations
from metres to feet, as the vast majority of logs and maps normalise, and with very large volumes of oil and gas
in Libya are scaled in feet. The new material has led to a still to be extracted, and with companies waiting for the
considerable expansion of the bibliography. opportunity to participate, it must be in everyone's inter-
This book could not have been written without ac- ests that this occurs sooner rather than later.
cess to the excellent database of Nubian Consulting Ltd A companion website with all figures can be found at:
and the generous financial support of ION who funded http://booksite.elsevier.com/9780444635174/
the drafting of the illustrations. We should particularly
like to thank Jason Robinson, Phill Houghton, Paul Don Hallett
Bellingham and Vinton Buffenmyer of ION for their Daniel Clark-Lowes
continued support and encouragement, and a special February, 2016
xi
C H A P T E R
1
History of Oil and Gas Exploration
O U T L I N E
1.1 Introduction 1 1.5 The Decade 1980–89 21
1.2 The Decade 1950–59 4 1.6 The Decade 1990–99 25
1.3 The Decade 1960–69 8 1.7 The Decade 2000–09 27
1.4 The Decade 1970–79 16 1.8 The Period 2010–15 31
1.1 INTRODUCTION died of fever. In 1822 a better equipped but poorly led
expedition set out under the joint leadership of Dixon
Libya has known many masters—Phoenician, Denham, an army lieutenant and Hugh Clapperton a na-
Carthaginian, Greek, Roman, Byzantine, Arab, Ottoman, val lieutenant, accompanied by a naval surgeon, Walter
Italian, and Allied military control after the Second Oudney. The expedition reached Lake Chad, but Oudney
World War. There was little organised scientific activ- died and Denham returned to England. Clapperton con-
ity before the annexation of Libya by Italy in 1911, al- tinued but was halted just 5 days march from the Niger
though a number of expeditions, some with scientific by a local sheikh. Most tragic of all was the expedition of
interests, passed through Libya in the 19th century. The Gordon Laing in 1826. He became the first European to
main objective of these expeditions, mostly organised reach Timbuktu, but was murdered by his Tuareg guides
by the London-based African Association, was to ex- as he returned through what is now Mali.1
plore the region southwards from Murzuq to Timbuktu, The first expedition with any pretensions of scientific
determine the course of the Niger River and assess the enquiry was conducted by Dr Heinrich Barth who joined
commercial potential of the area. The earliest of these ex- James Richardson's expedition in 1850, accompanied by
peditions was undertaken by Friedrich Hornemann who geologist and astronomer Dr Adolf Overweg. The ex-
travelled with a camel caravan from Egypt into Libya pedition crossed the Gharyan hills and the Hamadah al
passing through the oases of Siwa and Awjilah, and then Hamra and Overweg collected fossils between Murzuq
across the Haruj al Aswad to Murzuq, and subsequently and Ghat which were later identified by Heinrich Beyrich
to Tripoli. He returned to Murzuq in Aug. 1799 and was as Carboniferous, the first record of Carboniferous rocks
never seen again. In 1817 a military expedition led by in North Africa. Richardson and Overweg both died
the Bey of Tripoli traversed the coastal route from Tripoli on the expedition, but Barth explored the area between
to Cyrenaica and was accompanied by an Italian doctor, Murzuq, Lake Chad and Timbuktu, publishing a de-
Paolo Della Cella, who wrote an account of the expedi- tailed account of his travels in 1857/58. Other explorers
tion and noted the presence of fossils in Cyrenaica. This continued to explore the area into the 1860s and 1870s.
is the earliest known reference to geology in Libya. The At a time when borders were nonexistent French geol-
African Association's second attempt, this time start- ogists, working in eastern Algeria in the 1880s, identi-
ing from Tripoli, was made by George Lyon and Joseph fied Devonian rocks in the Jabal Akakus and Cretaceous
Ritchie in 1819 but only reached Murzuq where Ritchie rocks on the Hamadah al Hamra. Both of these areas are
1
P etroleum Geology of Libya Copyright © 2016 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/B978-0-444-63517-4.00001-6
2 1. HIsTOry Of OIL ANd GAs ExpLOrATION
now in Libya. Finally, after an Italian expedition in 1881 whilst flying over Tubruq in 1940 when his plane was
the Ottoman authorities discouraged further explora- shot down by Italian antiaircraft guns.
tion, and the European powers turned their attention to In these circumstances it is surprising that Italian ge-
other areas.2 ologists made any notable progress in examining and
In 1908 J.W. Gregory, professor of Geology at Glasgow documenting the geology of Libya, but the first rudi-
University, led an expedition to Cyrenaica under the mentary geological map of the accessible parts of Libya
auspices of the Jewish Territorial Organization to deter- was published in 1913 at a scale of 1:6,000,000,6 and a
mine whether Cyrenaica would be suitable as a home for number of papers were published on practical aspects
Jewish refugees recently displaced from eastern Europe. such as water supply, minerals and building material
This is not as strange as it may first appear as Jews had in the period up to the First World War. In the 1920s a
a long and prominent history in Cyrenaica dating back second generation of Italian geologists led by Ardito
to Roman times. The expedition studied the geography, Desio produced reports on some of the more remote
geology, agriculture and water supply of the area and regions of Libya. Desio was a charismatic figure: geol-
Gregory published an account of the geology in 1911 ogist, cartographer, explorer and mountaineer. In 1926
which described and named seven Tertiary formations, he led a geological expedition to the Al Jaghbub oasis
some of which are still in use today. The plan for a Jewish on the border with Egypt, and in 1931 he undertook a
settlement in Cyrenaica however was abandoned.3 more ambitious expedition by camel caravan across the
Libya was invaded by the Italians at the beginning of Sahara to the border of Sudan, followed by an expedi-
the Italian–Turkish war of 1911. The Italians expected to tion to the Tibisti mountains in 1935. He became director
be regarded as liberators by the Libyans, but this was a of the Libyan Geological Service from 1936 to 1940 when
grave miscalculation, which led to 20 years of almost in- he reported on deep aquifers, which did much to stimu-
cessant warfare. The Italian hold on Libya was tenuous late agriculture, and on surface oil seeps which led to the
until 1922 when Mussolini's Fascists seized control in birth of the Libyan oil industry.7 During his long career
Italy. They then embarked on La Riconquista of Libya un- he published over 120 papers on the geology of Libya
der generals Volpi and Graziani, which developed into during the period 1927–75.8 Traces of methane were re-
a protracted guerrilla war from 1922 to 1932, a war de- ported in a water well drilled near Tripoli in 19149 and
scribed as ‘long, petty and spiteful’. The western part of subsequently gas was noticed in several wells drilled
Libya was gradually subdued, but Murzuq, the capital on the coastal plain and on the Jabal Nafusah. In 1926
of Fezzan, was not conquered until 1930. In Cyrenaica, Crema found traces of oil in a well at Sidi al Masri in the
the Libyans, led by Omar Mukhtar, a local Sanussi suburbs of Tripoli.10 Under Desio's leadership Agip was
sheikh, put up tougher resistance, but in 1930 Graziani persuaded to conduct a 2-year reconnaissance campaign
was appointed Vice-Governor of Cyrenaica. Using the and to drill a 5,000 ft exploration well near Tripoli, which
brutal methods for which he was well-known, he confis- proved to be dry, but it was during this period that Desio
cated estates, exiled leaders, poisoned wells and erected predicted that the Sirt Basin would be a favourable area
a 200 km barbed wire fence along the border with Egypt. for hydrocarbon generation and accumulation (Fig. 1.1).
Nomads and their flocks were herded into concentration Further reconnaissance work in 1940 was cut short by
camps, one of which was located at Marsa al Brayqah the outbreak of war.11
where the future Esso port and terminal were to be built. The Italian geological investigations were ended by
With superior manpower and equipment Libyan resis- the Second World War which had a devastating im-
tance was finally crushed. Omar Mukhtar was captured pact on Libya. Three times the fighting surged across
in Sep. 1931 and after a summary trial he was hanged at Cyrenaica. Towns like Darnah and Tubruq were de-
Soluq.4 stroyed, and Binghazi was left in ruins. Most Italian
With the Italians now in full control they set about settlers returned to Italy during the early stages of the
establishing the so-called Fourth Shore. Confiscated es- war, and the countryside was left deserted. The allies
tates and ownerless land was appropriated and sold off finally drove the axis forces westwards and Tripoli sur-
cheaply. Mussolini encouraged Italian peasants and the rendered in Jan. 1943 and the rest of Libya was cleared
unemployed to acquire land, but the hot, dry climate by February. Large areas, particularly in the coastal
made farming difficult and the economic crisis of the plain west of Ajdabiya were heavily mined, and some
early 1930s made progress painfully slow. In 1937 there of these mines were not removed until the 1970s and
were only 1,300 Italian immigrant families farming in 1980s, ironically mostly by German contractors. For a
Libya, but under the leadership of Italo Balbo, Governor- number of years the salvaging of abandoned war ma-
General of Libya, a further 20,000 immigrants were terial provided a lucrative source of income to scrap
shipped to Libya in Dec. 1938 to occupy farms prepared metal dealers. From 1943 Libya was under the control of
for them in advance by the Fascist authorities.5 Balbo British and French military authorities, and the United
suffered the unusual fate of being killed by friendly fire States was granted the use of the former Libyan Grand
1.1 INTrOdUCTION 3
34°
Mediterranean Sea
33°
Tripoli
Darnah
Tunisia
Az Zawiyah Al Bayda
Misratah
Gharyan Binghazi Al Jabal al Akhdar Tubruq 32°
Al Burdi
Gulf of Sirt
Jabal
Nafusah Sirt 31°
Az Zuwaytinah
As Sidrah Ajdabiya E
Ras LanufAl Brayqah Cyrenaica g
Ghadamis Platform y
p 30°
t
Ghadamis
Jabal as
Basin
Sawda Hun 29°
Sirt
Basin
Al Qarqaf 28°
Arch
Al Haruj
Sabha al Aswad 27°
Awbari
Jabal Murzuq Tazirbu Jabal 26°
A Zalmah
ka Murzuq Waw al Kabir
Ghatku Basin ah 25°
s ss
Qu Waw an Namus
Algeria
al Al Kufrah
ur 24°
D
Jabal
Jabal Azbah 23°
Eghi
Al Kufrah Jabal
Niger Tibisti Basin AJrakbnaul 22°
Legend Awaynat
Recent volcanic terrains
Chad
21°
Principal sedimentary basins
Areas of thin sedimentary cover
20°
Palaeozoic and basement outcrops
0 100 200 300 km
10° 11° 12° 13° 14° 15° 16° 17° 18° 19° 20° 21° 22° 23° 24° 25°
Source: Geological map of Libya (1985)
FIG. 1.1 Libya: The Four Principal Basins.
The Sirt Basin is Mesozoic and Tertiary in age, whereas the Ghadamis, Murzuq and Kufrah basins are Palaeozoic, with variable post-Palaeozoic
cover. The volcanic rocks are Neogene to recent in age.
Prix racing circuit at Mellaha for use as an airfield. This base in the Mediterranean. Wheelus Field provided a
became the Wheelus Field. However, as John Wright supplementary base from which the United States was
perceptively wrote in 1969 ‘Colonels do not necessarily able to monitor events in the Middle East and southern
make the best rulers’. The allies all had hidden agen- Europe. In short, the allies were reluctant to leave Libya.
das. In Fezzan the French administered Ghat as part of Italy was formally stripped of its African empire in Feb.
southern Algeria, and Ghadamis as part of Tunisia, and 1947, but it still came as something of a shock when the
the British regarded Libya as a strategically important United Nations voted to grant independence to Libya in