The Pigna Barney Ophiolitic Complex and Associated Basaltic Rocks, Northeastern New South Wales, Australia

The Pigna Barney Ophiolitic Complex (PBOC) is a lithologically and chemically distinctive ultramafic-mafic melange which is largely confined to major fault zones in the Pigna Barney-Curricabark area, southern New England Orogen (NEO), northeastern New South Wales. For the most part, the PBOC lies along the arcuate, southern-most section of the Peel Fault System. This major steeply-dipping fault system marks the line of contact between a complex accretionary terrane (Zone B) lying to the east and north, and a significantly less-deformed volcanic arcrelated basin (Tamworth Belt) lying to the west and south. Fragments of the PBOC also lie within Zone B, especially along the Curricabark Fault Zone and along faulted contacts between the? pre-Devonian, largely hemipelagic Myra beds and Permian epiclastics of the Nambucca Association. The PBOC is everywhere in contact with adjacent stratigraphic associations, and non-tectonic contacts between its various component lithologies are exceedingly rare. The PBOC consists of: (i) a highly disrupted and incompletely preserved ophiolitic assemblage whose members consistently display atypically low abundances of "incompatible" elements (e.g. Ti, Zr, P); and (ii) a diverse range of igneous, sedimentary and metamorphic lithologies which generally occur as tectonic blocks in serpentinite-matrix melange (highly sheared tectonized harzburgite). In its type area the PBOC displays a crude internal ophiolitic stratigraphy which, at least on present orientation, consistently faces the Tamworth Belt to the southwest. Seven distinct lithological groups comprise the ophiolitic members of the PBOC. All groups are altered to varying degrees. In order of general structural position and inferred stratigraphic sequence these groups are: (1) depleted tectonized harzburgite - Fo92-91,Al₂0

Neutrinos

229 pages229 pages229 pagesThe Proceedings of the 2011 workshop on Fundamental Physics at the Intensity Frontier. Science opportunities at the intensity frontier are identified and described in the areas of heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms

Characterization of a Plume-Related Similar-to-800 Ma Magmatic Event and its Implications for Basin Formation in Central-Southern Australia

Geochemical and Nd isotopic studies are reported for widespread Late Proterozoic (approximately 800 Ma) mafic dyke swarms and volcanics in central-southern Australia. These mafic suites, although occurring over a large area of > 1000 km, show remarkably uniform geochemical and isotopic features characterised by similar trace element distribution patterns, smooth LREE-enriched patterns, and a limited range Of epsilon(Nd)(800 Ma) values (+2.4 to +4.2), closely resembling the Hawaiian basalts and the high-Ti Karoo flood basalts. These features suggest that this mafic province was probably derived by decompressional melting of a large-scale, uniform asthenospheric mantle plume. Upwelling of the plume resulted in domal uplift of the continental lithosphere, aulacogen-type rifting and onset of flood basalt volcanism. Large-scale crustal extension and thinning followed by thermal subsidence as a result of the plume activity may have been responsible for the formation of the large sedimentary basins in central-southern Australia