Definition The Acasta Gneisses are the oldest known rocks on the surface of the Earth. They are exposed in northern Canada, north of Great Slave Lake, east of Great Bear Lake with the approximate position of 65° 10′ N and 115° 30′ W. They have a composition close to granitic and ...
The Acasta Gneiss has withstood eons of geological history and stands as an enduring archetype for a patient and robust investment framework. Investment strategies Complementary investment backgrounds and a collaborative approach ideally provide a consistent pipeline of investment opportunities across risk...
An Iceland-like Setting for Generation of a ~4.02 Ga tonalite, Acasta Gneiss Complex, CanadaThe Acasta Gneiss Complex (AGC) contains the oldest known continental rocks on Earth with U-Pb zircon ages indicating crust formation between 3.6-4.03 Ga [Stern and Bleeker, 1997; Bowring and Williams,...
The Acasta Gneiss Complex of northwestern Canada comprises early Archean orthogneisses and includes the oldest known terrestrial rocks (3.94–4.03Ga). Previous zircon geochronological studies revealed the presence of zircon xenocrysts with ages up to 4.2Ga in the oldest rocks, indicating that the ...
Synonyms Acasta gneisses Definition The Acasta gneiss complex in northwestern Canada contains some of the oldest dated rocks on earth and the oldest dated using U-Pb in zircon. They therefore potentially preserve clues to the nature and history of earth's oldest crust. The geology of the ...
3920 Ma Acasta Gneiss. Geochimica et Cosmochimica Acta, 133: 68-96.Mojzsis SJ, Cates NL, Caro G, Trail D, Abramov O, Guitreau M, Blichert-Toft J, Hopkins MD, Bleeker W (2014) Component geochronology in the polyphase ca. 3920 Ma Acasta Gneiss. Geochim Cosmochim Acta 133:68-96Mo...
Gneiss The Acasta Gneisses are the oldest rocks so far discovered on the surface of the Earth. They are exposed in northern Canada, north of Great Slave Lake, east of Great Bear Lake with the...Bowring, Samuel A.Massachusetts Institute of TechnologyMartin, Hervé...
Archean Rocks in the Acasta Gneiss ComplexJessica OrwigEos, TRANSACTIONS, AMERICAN GEOPHYSICAL UNION
Acasta Gneiss Complexdetrital zirconU-Pb geochronologyArcheaneskerSlave cratonThe Acasta Gneiss Complex (AGC) is a 2,400 km2 Hadean-Mesoarchean terrane that contains the oldest known zircon-bearing rocks on Earth. Despite its importance for early Earth geology, only a small fraction (...
The oldest known evolved (felsic) rocks on Earth (c. 4.03 Ga) are found in the Acasta Gneiss Complex (AGC) in north‐western Canada and represent a fundamental keystone in unravelling the geological processes governing crustal growth and differentiation during the Hadean and early Archean. ...