Results 271 to 280 of about 69,328 (308)

U‐Pb zircon dating of Stockholm granite at Frescati

GFF, 1995
Abstract U‐Pb zircon dating of a sample of grey Stockhohn granite from Frescati just north of Stockholm yielded an upper intercept age of 1803+23 ‐19 Ma, similar to earlier age determinations, and interpreted as the age of crystallization of the granite. Ivarsson, C. & Johansson, A., 1995: U‐Pb zircon dating of Stockholm granite at Frescati.
Carin Ivarsson, Åke Johansson
openaire   +1 more source

An assessment of the utility of staurolite in U-Pb dating of metamorphism

Contributions to Mineralogy and Petrology, 1997
Pb isotope data, major and trace element compositions, fission track and synchrotron X-ray fluorescence analyses are presented for staurolites from nine pelitic schists in the continental United States to evaluate their potential use in U-Pb geochronology.
Antonio Lanzirotti, Gilbert N. Hanson
openaire   +1 more source

Direct U–Pb dating of vitrinite in coal

Chemical Geology
Uranium is often associated with organic matter forming U-organic matter complexes. Coal, as an organic rich material, is no exception but can it be dated using the uranium‑lead (U–Pb) method? We present U–Pb isotopic data, and trace elements concentrations directly measured on particles of the coal maceral vitrinite.
Sun, Beilei, Feng, Yuexing, Rodrigues, Sandra, Allen, Charlotte M., Esterle, Joan S.   +4 more
openaire   +2 more sources

NanoSIMS imaging method of zircon U-Pb dating

Science China Earth Sciences, 2016
We report an imaging method of zircon U-Pb dating with NanoSIMS 50L, which overcomes the significant U-Pb fractionation as the pit was sputtered deeper during conventional spot mode analysis and can be applied to irregular small grains or heterogeneous areas of zircon.
Sen Hu, YangTing Lin, Wei Yang, Wei-RZ Wang, JianChao Zhang, JiaLong Hao, WeiFan Xing   +6 more
openaire   +1 more source

U-Pb Dating of Zircon and 40Ar/39Ar Dating of Biotite at Bingham, Utah

Economic Geology, 2001
Uranium-lead dating of zircon and 40Ar/39Ar dating of biotite provide a new estimate of the age of the Bingham hydrothermal system. The U-Pb age of zircon from the Last Chance monzonite establishes the age of crystallization of this intrusion at 38.55 ± 0.19 Ma (2 σ , MSWD = 2.08). The oldest hydrothermal event in the monzonite is dated at 38.40 ± 0.16
W. T. Parry, P. N. Wilson, D. Moser, M. T. Heizler   +3 more
openaire   +2 more sources

Does U–Pb date Earth's core formation?

Nature, 2006
Arising from: B. J. Wood & A. N. Halliday Nature 437, 1345–1348 (2005); Wood & Halliday reply Constraining the timing of the formation of Earth's core, which defines the birth of our planet, is essential for understanding the early evolution of Earth-like planets.
Qing-zhu Yin, Stein B. Jacobsen
openaire   +1 more source

UPb dating of a carbonate subaerial exposure event

Earth and Planetary Science Letters, 1995
Ten samples of the dolomite fraction from the Lower Ordovician Oneota Formation, directly below the Sauk-Tippecanoe unconformity in Wisconsin, define a 238U206Pb age of 504 ± 14 Ma (MSWD = 190, 206Pb204Pb = 27–85, 238U204Pb = 84–795), which is in agreement with the 500 ± 4 Ma depositional age based on conodont biostratigraphy.
Bryce L. Winter, Clark M. Johnson
openaire   +1 more source

U-Pb dating of columbites: A geochronologic tool to date magmatism and ore deposits

Geochimica et Cosmochimica Acta, 1992
We have developed techniques for the U-Pb analysis of the mineral columbite [(Fe,Mn)(Ta,Nb)2O6], and report U-Pb ages obtained for three early Proterozoic columbites from the Baltic Shield of northern Sweden. The U-Pb ages of these columbites agree with other available geochronological data.
Rolf L Romer, James E Wright
openaire   +1 more source

Exploring the limits of in-situ U-Pb dating of metamorphic garnet

2022
<p>Recent advances in analytical techniques and instrumentation allow for the analysis of increasingly smaller sample volumes and lower concentrations. This development significantly expands the possibilities of in-situ geochronology, <em>e.g.</em>, LA-MC-ICPMS.
Aratz Beranoaguirre, Leo J. Millonig, Qiao Shu, Richard Albert, Horst R. Marschall, Jose Ignacio Gil Ibarguchi, Axel Gerdes   +6 more
openaire   +1 more source

U-Pb Dating of Fossils and Calcite: dating the Sedimentary and Paleontological record

We studied the feasibility of using laser ablation inductively coupled plasma mass spectrometry (LA–ICPMS) for U–Pb dating of fossils (vertebrate-invertebrate) and pedogenic calcite. U–Pb dating of hydrogenic and fossil material can be challenging because samples often contain low U levels and variable amounts of non ...
Heriberto Rochin-Banaga, Donald W. Davis, Sandra Kamo   +2 more
openaire   +1 more source