SHRIMP zircon U-Pb ages and tectonic implications for Indosinian granitoids of southern Zhuguangshan granitic composite, South China

Zircon U-Pb geochronology of the Ottawan Orogeny, Adirondack Highlands, New York: regional and tectonic implications

Both single and multigrain U-Pb zircon thermal ionization mass spectrometry (TIMS) as well as sensitive high resolution ion microprobe (SHRIMP ll) dating of two suites of Adirondack granites have yielded ages constraining the principal tectonomagmatic events of the Ottawan Orogeny to the interval ca 1090–1035 Ma. The earliest of these consists of mildly A-type hornblende granites of the Hawkeye...

New U-Pb SHRIMP zircon ages for pre-variscan orthogneisses from Portugal and their bearing on the evolution of the Ossa-Morena tectonic zone.

New SHRIMP U-Pb zircon ages for the Portalegre and Alcáçovas orthogneisses document a complex pre- Variscan history for the Iberian basement in Portugal. The available geochemical and geochronological data for the Alcáçovas orthogneiss (ca. 540 Ma) tend to favor its involvement in a Cadomian orogenic event. This is consistent with the development of an active continental margin setting at the e...

U=Pb zircon ages constrain the architecture of the ultrahigh-pressure Qinling–Dabie Orogen, China

New SHRIMP and TIMS zircon ages, Ar=Ar ages, and eclogite locations contribute significantly to our understanding of the ultrahigh-pressure Dabie Shan. (1) The geographic extent of the Yangtze craton that was subducted to ultrahigh pressure extends to the northern edge of the Dabie Shan. (2) The northern half of the Dabie Shan is a magmatic complex, intruded over a 10-Myr interval between 137 a...

SHRIMP zircon U–Pb age constraints on Neoproterozoic Quruqtagh diamictites in NW China

The Neoproterozoic Quruqtagh Group in the Tarim Block, NW China, contains multiple diamictites in the Bayisi, Altungol, Tereeken, and Hankalchough formations. These diamictites may represent three or possibly four discrete glaciations, although evidence for a glacial origin of the Bayisi and Altungol diamictite is ambiguous. To constrain their age and duration, we dated three volcanic beds (V1,...

U-Pb Zircon Ages and Pb Isotope Geochemistry of Gold Deposits in the Carolina Slate Belt of South Carolina