Priscoan (4.00-4.03 Ga) orthogneisses from northwestern Canada
Ancient crustal rocks provide the only direct evidence for the processes and products of early Earth differentiation. SHRIMP zircon U-Th-Pb dating has identified, amongst the Acasta gneisses of the western Slave Province, Canada, two metatonalites and a metagranodiorite that have igneous ages of 4002 ± 4, 4012 ± 6 and 4031 ± 3 Ga respectively. These are the first identified Priscoan terrestrial rocks. A record of metamorphic events at ∼3.75, ∼3.6 and ∼1.7 Ga also is preserved. These discoveries...[Show more]
|Collections||ANU Research Publications|
|Source:||Contributions to Mineralogy and Petrology|
|01_Bowring_Priscoan_(4.00-4.03_Ga)_1999.pdf||680.09 kB||Adobe PDF||Request a copy|
Items in Open Research are protected by copyright, with all rights reserved, unless otherwise indicated.