219:. Liberia also has medium-grade deposits of mixed hematite and magnetite. Laterite soils formed as rainfall slowly leached away silicates, a process known as laterization, leaving highly enriched medium and high-grade ores. The Mount Nimba area once had the best reserves, but almost of it has been extracted. The banded iron formations also host lode gold deposits. Because of extensive laterization, Liberia may have significant nickel and cobalt deposits.
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pipes in the underlying
Archean Man Shield, although very large deposits of diamonds have not been discovered. Because of political turmoil and violence, most diamond mining is limited to alluvial digging near the border with Sierra Leone and to date, there has not been extensive exploration for
89:
Greenstone belts, sequences of metamorphic and volcanic rocks associated with cratons and used by geologists to study early tectonics are found in south-central
Liberia, dating to 2.1 billion years ago. The
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195:
Virtually all of
Liberia's aquifers are in Precambrian basement rock, with the exception of some fractured igneous units and unconsolidated sediments on the northwestern coast.
132:, 32 kilometers north of the Todi Shear Zone form two heavily forested hills, lying unconformably on top of Archean gneiss. The Gibi Mountain Formation, in turn is overlain by
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siltstone, sandstone and shale. The conglomerate at the base of the Gibi
Mountain Formation is believed to be remnant glacial sediment from the global
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452:
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rocks in both the
Archean and the Pan-African rocks are metamorphosed to an intermediate amphibolite grade, part of the concept of
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dikes intrude the older
Precambrian rocks. Unmetamorphosed sandstone, siltstone, arkose and conglomerate, probably from the
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242:, better known as the chandelier tree, is a kimberlite botanical indicator, growing selectively atop the pipes.
70:, part of the West African Craton—a region of stable continental crust leftover from early continent formation.
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Along with Guinea, Sierra Leone and Ivory Coast, Liberia has some of the best diamond potential in Africa, in
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346:"Discovery of a kimberlite pipe and recognition of a diagnostic botanical indicator in NW Liberia"
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Liberia has some of the largest iron ore reserves in Africa, with iron content of 30% to 67%, in
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in which different metamorphic mineral assemblies form under similar temperature and pressure.
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is a 400 kilometer shear zone extending into
Liberia from Sierra Leone, where it separates the
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is largely extremely ancient rock formed between 3.5 billion and 539 million years ago in the
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may also be mineable. Sand and ceramic-grade clay are locally mined throughout the country.
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event in the
Neoproterozoic and corresponds with other glacial deposits around West Africa.
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34:, with some rocks from the past 145 million years near the coast. The country has rich
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in Sierra Leone, it appears that it formed between the late
Neoproterozoic and the
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238:, researching small, one hectare kimberlite pipes in Liberia found that
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are found in a narrow, five kilometer band along the coast, overlain by
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marine sediments formed between 23 million and 2.6 million years ago.
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143:. Based on similarities between the Gibi Mountain Formation and the
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formations weathered to higher concentrations by tropical rainfall.
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has contaminated the surface and groundwater in parts of
Liberia.
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Precambrian: Archean-Paleozoic (3.9 billion-539 million years ago)
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features, a form of remnant thrust fault terrain, that contains
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2.9 to 2.5 billion years ago both influenced the Archean rocks.
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35:
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Phanerozoic: Paleozoic-Cenozoic (539 million years ago-present)
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offshore placer deposits. Mercury used to separate gold in
215:, while lower grade ores with 30 to 40% iron are generally
211:. The high grade ores, with more than 60% are primarily
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151:. In both formations, there is a sequence of
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82:3.5 to 2.9 billion years ago and the
66:underlie 90% of Liberia, forming the
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58:Two billion to 1.6 billion year old
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698:Sahrawi Arab Democratic Republic
468:Democratic Republic of the Congo
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128:The clastic sedimentary rocks
46:and other minerals in ancient
1:
333:. British Geological Survey.
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344:Haggerty, Stephen (2015).
305:Geological Atlas of Africa
54:Stratigraphy and tectonics
38:resources as well as some
331:"Hydrogeology of Liberia"
303:SchlĂĽter, Thomas (2008).
171:In some places, isolated
453:Central African Republic
307:. Springer. p. 144.
199:Natural resource geology
130:Gibi Mountain Formation
205:banded iron formations
613:SĂŁo TomĂ© and PrĂncipe
473:Republic of the Congo
113:rocks, dating to the
240:Pandanus candelabrum
688:States with limited
236:Stephen E. Haggerty
115:Pan-African orogeny
797:Geology of Liberia
399:Geology of Africa
361:, p. 145-146.
348:. GeoScienceWorld.
123:metamorphic facies
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783:
715:other territories
488:Equatorial Guinea
145:Rokel River Group
100:Kenema Assemblage
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776:
775:(United Kingdom)
771:Tristan da Cunha
767:Ascension Island
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713:Dependencies and
406:Sovereign states
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229:artisanal mining
84:Liberian Orogeny
64:Paleoproterozoic
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80:Leonean Orogeny
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724:Canary Islands
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320:, p. 144.
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288:Liberia portal
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274:Geology portal
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161:Snowball Earth
104:Neoproterozoic
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32:Neoproterozoic
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528:Guinea-Bissau
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359:SchlĂĽter 2008
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318:SchlĂĽter 2008
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234:Geophysicist
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763:Saint Helena
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638:South Africa
628:Sierra Leone
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433:Burkina Faso
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191:Hydrogeology
170:
153:conglomerate
127:
96:Kasila Group
88:
77:
57:
17:
15:
690:recognition
643:South Sudan
533:Ivory Coast
209:Precambrian
111:amphibolite
745:(Portugal)
703:Somaliland
623:Seychelles
588:Mozambique
573:Mauritania
558:Madagascar
513:The Gambia
448:Cape Verde
260:References
224:kimberlite
181:Cretaceous
68:Man Shield
578:Mauritius
217:magnetite
207:from the
141:itabirite
134:quartzite
107:granulite
791:Category
769: /
765: /
758:(France)
752: /
730: /
726: /
678:Zimbabwe
653:Tanzania
503:Ethiopia
498:Eswatini
478:Djibouti
443:Cameroon
428:Botswana
213:hematite
149:Cambrian
98:and the
48:sediment
40:diamonds
30:and the
754:RĂ©union
750:Mayotte
741:Madeira
736:(Spain)
732:Melilla
663:Tunisia
633:Somalia
618:Senegal
603:Nigeria
593:Namibia
583:Morocco
548:Liberia
543:Lesotho
493:Eritrea
463:Comoros
438:Burundi
413:Algeria
250:kyanite
246:Bauxite
185:Neogene
173:diabase
60:Archean
28:Archean
23:Liberia
19:geology
773:
756:
743:
673:Zambia
668:Uganda
608:Rwanda
563:Malawi
523:Guinea
418:Angola
254:barite
177:gabbro
157:arkose
137:klippe
119:Gneiss
728:Ceuta
648:Sudan
598:Niger
553:Libya
538:Kenya
518:Ghana
508:Gabon
483:Egypt
423:Benin
658:Togo
568:Mali
458:Chad
252:and
175:and
109:and
78:The
62:and
44:gold
36:iron
16:The
21:of
793::
248:,
155:,
117:.
42:,
391:e
384:t
377:v
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