462 research outputs found

    Coupled Zircon-Rutile U-Pb Chronology: LA ICP-MS Dating, Geological Significance and Applications to Sediment Provenance in the Eastern Himalayan-Indo-Burman Region

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    U-Pb dating by LA ICP-MS is one of the most popular and successful isotopic techniques available to the Earth Sciences to constrain timing and rates of geological processes thanks to its high spatial resolution, good precision (absolute U/Pb age resolution of ca. 2%, 2s), rapidity and relative affordability. The significant and continuous improvement of instrumentation and approaches has opened new fields of applications by extending the range of minerals that can be dated by this method. Following the development and distribution to the community of good quality reference materials in the last decade, rutile U-Pb thermochronology (with a precision only slightly worse than zircon) has become a commonly used method to track cooling of deep-seated rocks. Its sensitivity to mid- to low-crustal temperatures (~450 °C to 650 °C) is ideal to constrain exhumation in active and ancient orogens as well as thermal evolution of slow-cooled terranes. Recrystallization and secondary growth during metamorphism and the presence of grain boundary fluids can also affect the U-Pb isotopic system in rutile. A growing body of research focusing on U-Pb dating of rutile by LA ICP-MS is greatly improving our understanding of the behavior of this mineral with regards to retention of radiogenic Pb. This is key to fully exploit its potential as a tracker of geological processes. The latest developments in this field are reviewed in this contribution. The combined application of U-Pb zircon and rutile chronology in provenance studies, particularly when complemented by lower-T thermochronometry data, allows the isotopic characterization of the sources across a wide range of temperatures. The benefits of applying detrital zircon-rutile U-Pb chronology as a coupled provenance proxy are presented here, with a focus on the Eastern Himalayan-Indo-Burman region, where a growing number of successful studies employs such an approach to help constrain river drainage and basin evolution and to infer feedback relationships between erosion, tectonics and climat

    Some consequences of symmetry in strong Stieltjes distributions

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    The main purpose of this work is to study a class of strong Stieltjes distributions (t), defined on an interval (a, b) ⊆ (0, ∞), where 0 < < b ≤ ∞ and a = ²/b which satisfy the symmetric property (dψ(t))/t[super]ω=-(dψ(β^2/t))/((β^2/t)[super]ω), tε (a,b), 2ωε We investigate the consequences of this symmetric property on the orthogonal L-polynomials related to distributions ψ(t)and which are the denominators of the two-point Pade approximants for the power series that arise in the moment problem. We examine relations involving the coefficients of the continued fractions that correspond to these power series. We also study the consequences of the symmetry on the associated quadrature formulae

    Data-Intensive Modelling and Simulation in Life Sciences and Socio-economical and Physical Sciences

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    First paragraph: This special issue of the journal Data Science and Engineering is a result of the work fostered by the ICT COST Action IC1406 High-Performance Modelling and Simulation for Big Data Applications (cHiPSet), an EU-funded research network across 30+ European countries and overseas partners (http://chipset-cost.eu/).Output Type: Editoria
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