Some Archean Rocks

 

Acasta Gneiss - 4.031 Ga granodiorite gneiss from the Acasta River, far-northern Canada.

 


 

Greenlandite - 3.8 Ga fuchsite-quartz gneiss from southwestern Greenland.

 


 

Isua Supracrustal Belt - 3.8 Ga metamorphosed banded iron formation from southwestern Greenland.

 


 

Barberton Greenstone Belt - 3.482-3.657 Ga metakomatiite (= serpentinite) from northeastern South Africa.

 


 

Carbonado diamondites (mid-Mesoarchean, ~3.2 Ga) - supernova rocks that impacted on Earth in the Brazil and Central African Republic area (these were originally next to each other, before the ancient Gondwana continent rifted apart).

 


 

Compeau Creek Gneiss - ~2.6-3.0 Ga (?) from near Marquette, Michigan’s Upper Peninsula, USA.

 


 

Carbon Leader Gold Ore - 2.9 Ga auriferous, uraninitic stromatolite rock from the Blyvooruitzicht Gold Mine, South Africa.

 


 

Witwatersrand Conglomerate - 2.76-2.89 Ga auriferous, pyritic quartz-pebble conglomerate from the Stilfontein Mine, northeastern South Africa.

 


 

Goldman Meadows Iron-Formation - 2.87 Ga magnetite meta-BIF from the Atlantic City Iron Mine, Wyoming, USA.

 


 

Red Lake Gold Ore - 2.85 Ga metabasalt with 2.712-2.723 gold mineralization from the Red Lake Mine, Ontario, Canada.

 


 

Belomorian Complex - 2.7-2.8 Ga retrograde eclogite from near Polarnie Zory, Kola Peninsula, far-northwestern Russia.

 


 

Kinawa Granite” - 2.72-2.75 Ga migmatite from southeastern Brazil.

 


 

Stillwater Complex - 2.71 Ga chromitite from the Beartooth Mountains of southern Montana, USA.

 


 

  

Stillwater Complex - 2.71 Ga sulfidic serpentinite (left) & sulfidic tremolitite (center)  & massive PGE-rich sulfide (right) from the Stillwater Mine, Beartooth Mountains, southern Montana, USA.

 


 

Pyke Hill Komatiite - 2.703-2.715 Ga metakomatiite from Pyke Hill, eastern Ontario, Canada.

 


 

Cadillac Gold Ore - 2.7 Ga hydrothermal quartz-gold vein from the Cadillac Mine, Quebec, Canada.

 


 

Temagami Iron-Formation - 2.7 Ga jaspilite from the Sherman Iron Mine, Ontario, Canada.

 


 

Prohibition Iron-Formation - ~2.7 Ga ferruginous banded chert from near Meekatharra, Western Australia.

 


 

 

Mona Formation - ~2.7 Ga phyllite (left) & greenstone (right) from the Marquette area, Michigan’s Upper Peninsula, USA.

 


 

Kitchi Formation - ~2.7 Ga volcanic metabreccia at Deer Lake, Michigan’s Upper Peninsula, USA.

 


 

Ely Greenstone - 2.6-2.7 Ga epidotite from the Dunka Mine area, Minnesota.

 


 

Deer Lake Peridotite - ~2.5-2.7 Ga (?) serpentinite from Deer Lake, Michigan’s Upper Peninsula, USA.

 


 

Keivy Schist - staurolite schist having a 2.5-2.7 Ga protolith age from Mt. Ploskaya, east-central Kola Peninsula, Murmansk Region, far-northwestern Russia.

 


 

 

Sar-e-Sang Lapis Lazuli Deposit  - 2.7-2.4 Ga (?) lazuritic metamorphite (right) & lazuritic-pyritic marble (left) from the Sakhi Formation (Neoarchean, 2.4-2.7? Ga) in the Sar-e-Sang Mining District, Hindu Kush Mountains, northeastern Afghanistan.

 


 

Nuummite” - 2.68 to 2.77 Ga anthophyllite-gedrite amphibolite from an island south of Nuuk, southwestern Greenland.

 


 

English River Subprovince intrusion (“Crystal Gold Granite”) - 2.66-2.71 Ga porphyritic granite from Second Mountain Quarry, western Ontario, Canada.

 


 

Orbicular granodiorite - 2.687 Ga decorative stone from Warroan Hill, Western Australia.

 


 

Timiskaming Conglomerate - <2.674 Ga polymict conglomerate having komatiite & BIF pebbles from Kirkland Lake, Ontario, Canada.

 


 

 

Preissac-Lacorne Batholith - 2.630-2.675 Ga molybdenite-quartz pegmatite sample (left) & bismuthinite-quartz-K-feldspar pegmatite sample (right) from Moly Hill, Quebec, Canada.

 


 

Milbank Granite (“Dakota Mahogany Granite”) - 2.6-2.7 Ga porphyritic granite from a quarry near Milbank, South Dakota, USA.

 


 

 

Tan Brown Granite” & “Sapphire Brown Granite” - Archean porphyritic granites from Andhra Pradesh State, southern India.

 


 

Orthogneiss from the Mesoarchean or Neoarchean along the Beartooth Highway, southern Montana, USA.

 


 

Belomorian Terrane - Neoarchean ruby-bearing garnetiferous orthogneiss from Khit Island, Karelia, Russia.

 


 

Great Dike of Rhodesia - 2.57-2.58 Ga chromitite (with serpentine) from the Caesar Mine, northern Zimbabwe, southern Africa.

 


 

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