Stratigraphic data and ^Ar-39Ar ages for the Early Cretaceous ParaniEtendeka flood basalts indicate that the main magmatic episode lasted for several m.y. (129-134 Ma) and was linked to the northward opening of the South Atlantic Ocean, but with some earlier magmatism (135-138 Ma) found inland far from the eventual oceanic rift. The regional distribution of distinct high-TiN (Urubici, Pitanga, ...

New U-Th-Pb zircon data (SIMS) from three intrusive phases of the Palaeoproterozoic Viterliden intrusion in the western Skellefte District, central Fennoscandian Shield, dates igneous emplacement in a narrow time interval at about 1.89 Ga. A locally occurring quartz-plagioclase porphyritic tonalite, here dated at 1889± 3 Ma, is considered the youngest of the intrusive units, based on the new ag...

A Silurian regional tectonometamorphic event has been widely recorded by different geochronological methods in the Sierras Pampeanas, NW Argentina and Precordillera. It took place between ca. 445 420 Ma after Hirnantian (late Ordovician) glaciogenic sedimentation. Three domains are recognized. 1) The eastern Pampeanas Puna mainly record focused westward ductile thrusting heating. 2) In westernm...

Abstract Cordilleran arcs are built by long periods of steady-state magmatism punctuated transient high-flux magmatic episodes or flare-ups. Such flare-ups, manifested as prodigious silicic volcanism and magmatism, result from geodynamic perturbations that cause elevated rates magma addition to the crust. Questions remain, however, about how quantitatively compare between flare-up modes arc aft...