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The Bingham porphyry Cu–Au–Mo deposit, Utah, may only be world-class because of substantial contributions of sulfur and metals from mafic alkaline magma to an otherwise unremarkable calc-alkaline system. Volcanic mafic alkaline rocks in the district are enriched in Cr, Ni, and Ba as well as Cu, Au, platinum group elements (PGE), and S. The bulk of the(More)
With the goal to study the physical and chemical evolution of ices in solar-mass systems, a spectral survey is conducted of a sample of 41 low luminosity YSOs (L ∼ 0.1 − 10 L ⊙) using 5–38 µm Spitzer Space Telescope and 3–4 µm ground-based spectra. The sample is complemented with previously published Spitzer spectra of background stars and with ISO spectra(More)
We have identified four circumstellar disks with a deficit of dust emission from their inner 15-50 AU. All four stars have F-G spectral type, and were uncovered as part of the Spitzer Space Telescope " Cores to Disks " Legacy Program Infrared Spectrograph (IRS) first look survey of ∼100 pre-main sequence stars. Modeling of the spectral energy distributions(More)
  • V C Geers, J.-C Augereau, +11 authors B Merín
  • 2006
Aims. We search for Polycyclic Aromatic Hydrocarbon (PAH) features towards young low-mass (T Tauri) stars and compare them with surveys of intermediate mass (Herbig Ae/Be) stars. The presence and strength of the PAH features are interpreted with disk radiative transfer models exploring the PAH feature dependence on the incident UV radiation, PAH abundance(More)
Zircon (U-Th)/He thermochronometry is an established radiometric dating technique used to place temporal constraints on a range of thermally sensitive geological events, such as crustal exhumation, volcanism, meteorite impact, and ore genesis. Isotopic, crystallographic, and/or mineralogical heterogeneities within analyzed grains can result in dispersed or(More)
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