The age of the lower crust of the central part of the Columbia supercontinent: A review of zircon data

We have compiled data on textures, trace element contents, Hf isotope compositions and U-Pb ages of zircons from lower crustal xenoliths the central part Columbia supercontinent in Precambrian areas North America, Siberia Northern Europe to address question when host rocks became continental crust. The time crust reached its current state, a layer high-pressure granulite-facies rocks, is dated by that equilibrated with observed metamorphic association. Magmatic can provide age protolith crystallization, which did not necessarily occur within Those Archean cratonic (the Slave, Wyoming, Superior, Siberian Karelian cratons Belomorian mobile belt NW Russia) yield predominantly (3.5–2.6 Ga). Addition Proterozoic material rarely recorded magmatic (2.50–2.47 1.64 association formed times has been preserved Slave Superior despite later re-heating events. In other Columbia, was reworked during Paleoproterozoic orogenic At present, 1.9–1.7 Ga old granulitic predominates, assembly supercontinent. Nevertheless, sporadic surviving show remnants are occasionally preserved. Mesoproterozoic younger extensional events anorogenic magmatism occurred across wide area at southern margins Wyoming cratons, belt, Yavapai Mazatzal provinces Cheyenne belt. These caused significant reworking migmatization formation main differences upper histories slow cooling long duration thermal