the origin of the proterozoic choghart iron oxide deposit in the bafq mining district of central iran has been the subject of a long-standing dispute. some authors believe that it was formed from magma, while others suggest metasomatic replacement of preexisting rocks. the present study on the basis of new oxygen isotope, ree and geochemical data concludes that neither of these two hypotheses c...

Neodymium model ages for fine-grained formations of the Paleoproterozoic Huronian Supergroup (McKim, Pecors, Gowganda, Gordon Lake) range from 3.00 to 2.55 Ga and indicate a provenance dominated by the Late Archean Superior Province to the north and west. The stratigraphically highest unit (Gordon Lake Formation) has a distinctive Nd-isotopic composition, with TDM being 100-400 Ma younger than ...

Low-Angle Normal Faults (LANFs) represent in the central Southern Alps area (N Italy) main structures along which Variscan basement is contact with Upper Carboniferous-Permian volcanic-sedimentary succession. Tourmalinites frequently occur LANFs, usually replacing former cataclasites. The mineralogy and chemical composition of tourmalinites point to a metasomatic origin. together high-angle fau...