Rare Earth Element (Summary Of Stephen B. Castor and James B. Hedrick Paper From Geological Perspective)
Exploration :
Potential
area of hard rock REE deposit mostly found in rock that older than Precambrian
(underlain by Precambrian rock). In Placer deposit, REE deposit is associated
with granitic rocks (some are Mesozoic - Phanerozoic) or high-grade metamorphic
rocks (usually Precambrian), or both.
Technique that can be use:
1. Radiometric exploration technique.
2. Geochemical prospecting using heavy mineral concentration of active
stream sediments.
3. Multielement analytical techniques.
4. X-ray fluorescence or neutron activation analysis
5. Inductively coupled plasma (ICO) Spectroscopy.
6. Biochemical prospecting (Plant ash contain).
7. Surface exploration (trenching, pitting, and dredging).
8. Drilling that utilizing core sampling.
9. Absorption bands in the visible spectrum differentiation.
10. Geophysical methods of gravity surveys and airborne or magnetic surveys
(sometimes using seismic surveys).
Table 1. Known REE deposits
Location
|
Country
|
Discovered
|
REE
|
Mineral Container
|
Rock Association
|
Associate Mineral
|
Age of REE Mineralization
|
Deposit Type
|
Bayan Obo
|
Mongolia
|
1927
|
Rare earth oxide, LREE
|
Bastnasite, monazite
|
Iron ore, silicate ore, dolomite
|
Alkali rich alteration (fenitization),
predominated by sodic amphibole and
potash feldspar
|
1600 Ma (Yuan et al. 1992)
or 550 to 400 Ma (Chao et al. 1997)
|
Iron-LREE-niobium
|
The Pea Ridge
|
Missouri
|
?
|
LREE, HREE, unknown
|
Monazite, xenotime
|
Breccia pipes associated with 1.48-Ga granite and syenite
|
?
|
?
|
Iron
|
Mineville
|
New York
|
?
|
Rare earth oxide, unknown
|
Apatite
|
Gabro, Syenite
|
Magnetite (?)
|
?
|
Magnetite (Mill tailings)
|
Kiruna
|
Sweden
|
?
|
Rare earth oxide
|
Apatite, monazite
|
?
|
Magnetite, Hematite (?)
|
?
|
Magnetite and Hematite
|
Olympic Dam
|
South Australia
|
?
|
LREE/HREE (?)
|
Monazite, bastnasite
|
Breccia
|
Quartz, sericite, fluorite, barite, sulfide
|
Proterozoic (?)
|
Copper-uranium-silver-gold
|
Mountain Pass
|
California
|
1954
|
Rare earth oxide, LREE, HREE
|
Bastnasite
|
Granulie-grade gneiss, alkaline plutons, carbonatite
and alkaline dikes, ultra potassic alkaline igneous rock.
|
Calcite or dolomite, basite, strontianite, talc,
galena
|
1,4 Ga
|
Carbonatite
|
Powderhorn
|
Colorado
|
?
|
Rare earth oxide (?)
|
?
|
?
|
?
|
Cambrian (?)
|
Iron hill carbonatite
|
North Fork Area
|
Idaho-Montana Border
|
?
|
Rare earth oxide (?)
|
Monazite, allanite, ancylite
|
Carbonatite dyke
|
?
|
Phanerozoic (?)
|
Carbonatite
|
Oka
|
Quebec
|
?
|
REE (?)
|
Britholite
|
Carbonatite dyke
|
?
|
?
|
Carbonatite
|
St-Horore
|
Quebec
|
?
|
LREE, Rare earth oxide
|
Bastnasite, monazite
|
?
|
?
|
Late Proterozoic (?)
|
Carbonatite
|
Barreiro complex at Araxa
|
(Minais Gerais) Brazil
|
?
|
Rare earth oxide
|
Aeschynite (?)
|
Niobium ore
|
?
|
?
|
Carbonatite
|
Kangankunde Hill
|
Malawi
|
?
|
LREE (?)
|
Monazite-thorium free (almost), bastnasite,
florencite-goyazite
|
Carbonatite dyke
|
?
|
?
|
Carbonatite
|
Wigu Hill
|
Tanzania
|
?
|
Rare earth oxide
|
Monazite, REE fluorocarbonate
|
Carbonatite dyke
|
?
|
?
|
Carbonatite
|
Palabora carbonatite
|
South Africa
|
?
|
Rare earth oxide
|
?
|
Potassic alkaline complex
|
Copper, apatite
|
Early Proterozoic (?)
|
Carbonatite
|
Kizilkaoren
|
Turkey
|
?
|
LREE
|
Bastnasite-fluorite-barite
|
Carbonatite dyke, pronolite, trachytes, alkaline
pyroclastic rock
|
Fluorite, barite
|
?
|
Carbonatite
|
Longnan, Jiangxi
|
China
|
?
|
HREE, yttrium-rich
|
?
|
Clay (ionic absorption clay), alkaline igneous rock,
carbonatite
|
Halloysite, kaolinite,
quartz, feldspar
|
?
|
Laterites
|
Xunwu, Jiangxi
|
China
|
?
|
LREE, lanthanum-rich
|
?
|
Clay (ionic absorption clay) , alkaline igneous
rock, carbonatite
|
Halloysite, kaolinite,
quartz, feldspar
|
?
|
Laterites
|
Mount Weld
|
(Southern Western) Australia
|
?
|
LREE, HREE, yttrium
|
Churchite (HREE), phosphate and alumino-phosphate
(LREE)
|
Carbonatite
|
Niobium, tantalum
|
20 Ga (Duncan and Willet,
1990)
|
Laterite
|
Yangibana
|
(Northern Western) Australia
|
?
|
Rare earth oxide
|
?
|
Carbonatite, alkaline rocks
|
?
|
?
|
Laterite
|
Araxa
|
Brazil
|
?
|
Rare earth oxide
|
Gorceixite, goyazite
|
Carbonatite
|
Phosphate mineral
|
?
|
Laterite (supergene)
|
Catalao I Complex
|
Brazil
|
?
|
Rare earth oxide
|
Gorceixite
|
Phosphatic
|
Secondary phosphate mineral
|
?
|
Laterite
|
Maicuru Complex, Para
|
(Northern) Brazil
|
?
|
?
|
Phosphatic
|
Carbonatite
|
?
|
?
|
Laterite
|
Cerro Impacto, Amazon
|
Venezuela
|
?
|
?
|
?
|
Carbonatite
|
?
|
?
|
Laterite
|
Serra negra
|
Minas Gerais
|
?
|
LREE, HREE, titania
|
Anatose
|
Deeply weathered carbonatite
|
?
|
?
|
Laterite
|
Mrima Hill
|
Kenya
|
?
|
?
|
Monazite
|
Carbonatite
|
?
|
?
|
Laterite
|
?
|
Montenegro
|
?
|
?
|
Hydroxylbastnasite
|
Karst, bauxite
|
?
|
Upper Jurassic (?)
|
Laterite
|
Eneabba
|
Australia
|
?
|
?
|
Monazite
|
Heavy mineral sands
|
Rutile-zircon-ilmenite
|
Late Tertiary - early
pleistocene
|
Placer
|
Geographe Bay
|
Australia
|
?
|
?
|
Monazite
|
High grade metamorphic (Paleo sand)
|
Ilmenite-zircon
|
Pleistocene - recent
|
Placer
|
?
|
Southeast Asia (?)
|
?
|
?
|
Monazite, xenotime
|
Tin, zircon, titania
|
?
|
Placer
|
|
Green Cove Springs
|
Florida
|
1952 - (1994)
|
?
|
Monazite
|
Sands
|
Titania, zircon
|
Pleistocene
|
Placer
|
Carolina monazite belt
|
America
|
1885 - 1917 (?)
|
?
|
Monazite
|
Nonmarine sand
|
?
|
?
|
Placer
|
Cascade
|
Idaho
|
1950 (?)
|
?
|
Monazite
|
Gravel
|
?
|
?
|
Placer
|
Bear Valley
|
Idaho
|
?
|
?
|
Monazite, yttrium bearing-euxenite
|
?
|
Niobium, tantalum
|
?
|
Placer
|
?
|
Northern Idaho
|
?
|
?
|
Xenotime
|
Placer gold mining (?)
|
Gold
|
?
|
Placer
|
Blind River, ontario
|
Canada
|
1950 - 1970 (?) and 1986 -
1990
|
?
|
Monazite, uraninte, brannerite
|
Metamorphosed Conglomerate
|
?
|
Early proterozoic
|
Placer
|
Music Valley
|
(Southern) California
|
?
|
Rare earth oxide
|
Xenotime, monazite
|
Gneiss
|
?
|
Precambrian (?)
|
Placer
|
Bald Mountain
|
Wyoming
|
?
|
?
|
Monazite
|
Conglomerate
|
?
|
Cambrian (?)
|
Placer
|
Lovozero, Kola Peninsula
|
Russia
|
?
|
Rare earth oxide, titanium,
|
Eudilytic, loparite
|
Nepheline syenites, nephelinites, porphyritic rock
|
Nepheline, microcline,
aegirine, arfvedsonite, hydrosodalite, natrolite, sodalite, urtites,
feldspar-aegerine, juvite, malignite
|
Paleozoic (?)
|
Peralkaline
|
Pajarito Mountain
|
New Mexico
|
?
|
Rare earth oxide (?)
|
Eudialyte
|
Syenite intrusion
|
?
|
?
|
Peralkaline
|
Kipawa Lake
|
Ontario
|
?
|
Yttrium, zirconium
|
Eudialyte, mosandrite, britholite
|
Syenite
|
?
|
~Grenville orogeny (?)
|
Peralkaline
|
Strange Lake
|
Quebec-Labrador
|
?
|
Zirconium, yttrium, HREE
|
Gadolinite, bastnasite, kainosite
|
Granite
|
Niobium, beryllium,
tantalum
|
?
|
Peralkaline
|
Bokan Mountain
|
Alaska
|
?
|
HREE, yttrium (?)
|
?
|
Granite-syenite
|
?
|
?
|
Peralkaline
|
Thor Lake
|
Canada
|
?
|
HREE, yttrium (?)
|
?
|
Granite-syenite
|
?
|
?
|
Peralkaline
|
Ilmasussaq
|
Greenland
|
?
|
Zirconium, yttrium
|
Eudialyte
|
Syenite
|
?
|
Proterozoic (?)
|
Peralkaline
|
Norra Karr
|
Sweden
|
?
|
Zirconium
|
Eudialyte
|
Syenite
|
?
|
Proterozoic (?)
|
Peralkaline
|
?
|
Saudi Arabia
|
?
|
Zirconium, yttrium, LREE, HREE (?)
|
?
|
Alkaline granite
|
?
|
?
|
Peralkaline
|
Brockman
|
Australia
|
?
|
Zirconium, yttrium
|
?
|
Metamorphosed rhyolite tuff (?)
|
Niobium, tantalum, conium
|
Proterozoic?
|
Peralkaline
|
Dubbo, New South Wales
|
Australia
|
?
|
Zirconium, yttrium, HREE
|
?
|
Altered intrusive trachyte (?)
|
Tantalum
|
Jurassic (?)
|
Peralkaline
|
Pocos De Caldas
|
Brazil
|
?
|
?
|
Eudialyte
|
Peralkaline syenite
|
?
|
Mesozoic - early tertiary (?)
|
Peralkaline
|
Khibina, Kola Peninsula
|
Russia
|
?
|
?
|
Eudialyte
|
Peralkaine syenite
|
?
|
Paleozoic (?)
|
Peralkaline
|
Maoniuping mine, Sichuan
|
China
|
?
|
?
|
Bastnasite,, chevkinite, xenotime, britholite,
allanite, monazite
|
Quartz syenite, carbonatite dyke (?)
|
Barite, carbonate, calcite,
quartz, fluorite, feldspars, aegerine-augite, sulfide
|
?
|
Vein
|
Weishan mine, Shangdong
|
China
|
?
|
?
|
Bastnasite,, chevkinite, xenotime, britholite,
allanite, monazite, titanium
|
Quartz syenite, carbonatite dyke (?)
|
Barite, carbonate, calcite,
quartz, fluorite, feldspars, aegerine-augite, sulfide, dolomite, amohiboles,
thorite, niobium
|
?
|
Vein
|
Steenkampskraal
|
South Africa
|
?
|
LREE (?)
|
Monazite-apatite
|
Granite
|
Quartz, magnetite, sulfide
|
Proterozoic (?)
|
Vein
|
Crescent Park
|
Nevada
|
?
|
LREE (?)
|
Monazite-apatite
|
Granite
|
?
|
Precambrian (?)
|
Vein
|
Keronge, Burundi
|
East Africa
|
?
|
LREE, cerium
|
Bastnasite, monazite, cerianite, rhabdophane
|
Quarzite, schist
|
Quartz, barite
|
Precambrian (?)
|
Vein
|
Pilanesberg
|
South Africa
|
?
|
?
|
Britholite
|
Peralkaline complex
|
?
|
?
|
Vein
|
Lemhi Pass
|
Idaho-Montana
|
?
|
LREE
|
Thorium
|
?
|
Quartz
|
?
|
Vein
|
Diamond Creek
|
Idaho-Montana
|
?
|
LREE
|
Thorium
|
?
|
Quartz
|
?
|
Vein
|
The Snowbird
|
Montana
|
?
|
?
|
Parasite
|
?
|
Quartz, carbonate, fluorite
|
Cretaceous (?)
|
Vein
|
Hall Mountain, Port hill
|
Idaho
|
?
|
?
|
Thorite
|
?
|
Quartz, carbonate, fluorite
|
?
|
Vein
|
Bear Lodge
|
Wyoming
|
?
|
?
|
?
|
?
|
Trachyte, phonolite
|
Tertiary (?)
|
Vein
|
Nolan's Bore
|
Australia
|
?
|
Rare earth oxide
|
Apatite, cheralite
|
?
|
?
|
?
|
Vein-like
|
Tien Shan Range
|
Kyrgyzstan
|
?
|
Yttrium, HREE
|
Synchisite, bastnasite, monazite, xenotime
|
?
|
Molybdenum, silver,
bismuth, zircon
|
?
|
?
|
Naboomspruit
|
South Africa
|
?
|
?
|
Monazite
|
?
|
?
|
?
|
Fluorspar
|
Gallinas Mountains
|
New Mexico
|
?
|
?
|
Bastnasite
|
?
|
?
|
?
|
Fluorspar
|
Athabasca Group, Alberta
|
Canada
|
?
|
HREE-uranium
|
Xenotime
|
Sandstone
|
?
|
Late Precambrian (?)
|
?
|
?
|
(Western) Australia
|
?
|
HREE, uranium
|
?
|
Quartzite
|
?
|
?
|
?
|
?
|
(Northern) Australia
|
?
|
allanite
|
pegmatite
|
?
|
?
|
Pegmatite
|
|
?
|
Vietman
|
?
|
LREE, HREE
|
?
|
Limestone (metasomatic)
|
?
|
Paleozoic (?)
|
?
|
?
|
Montana
|
?
|
Yttrium
|
?
|
?
|
?
|
Permian (?)
|
Marine Phosphorites
|
Idaho
|
?
|
yttrium
|
?
|
?
|
?
|
Permian (?)
|
Marine Phosphorites
|