Proterozoic and Phanerozoic basement terranes of Mexico from Nd isotopic studies

摘要: Nd isotopic data were collected on Precambrian crystalline rocks exposed in northern, eastern, and southern Mexico, as well from lower crustal xenoliths central order to constrain the age character of Mexican basement. The indicate that basement belonging Grenville (1.0 Ga) tectonothermal event extends Los Filtros, Chihuahua, northern Oaxaca, Mexico. These all have average residence times (TDM ages) range 1.60 1.35 Ga. We infer this results mixing 1.9 Ga or older recycled continental crust with 70% 90% newly derived mantle-crustal material during orogeny. To west Precambrian, contains large amounts Phanerozoic (probably Paleozoic) crust, identified TDM ages less than 1.0 represented by these may been emplaced suspect terranes Mesozoic Cordilleran events. Alternatively, apparent Paleozoic underlies parts Mexico connect metamorphic Acatlan complex together they would constitute a continuation Appalachian-Caledonian orogenic belt through Our do not preclude either two models.