Results 41 to 50 of about 28,842 (211)

Characterization of Yellow-Green Hetian Jade in Qiemo—Ruoqiang, Xinjiang

open access: yesYankuang ceshi, 2022
BACKGROUND The Hetian nephrite belt in Xinjiang is the largest nephrite ore belt in the world, with a length of about 1300km. In addition to white, gray, black and brown nephrite, the Qiemo—Ruoqiang zone, Xinjiang also produces a yellow-green nephrite ...
ZHANG Xiaohui   +3 more
doaj   +1 more source

Electron microprobe technique for U-Th-Pb and REE chemistry of monazite, and its implications for pre-, peak- and post- metamorphic events of the Lutzow-Holm Complex and the Napier Complex, East Antarctica [PDF]

open access: yes, 2006
Monazites in high-grade metapelites from the Lutzow-Holm Complex and Napier Complex have been examined in terms of U, Th, Pb and rare earth element (REE) chemistry using an electron microprobe.
Tomokazu Hokada, Yoichi Motoyoshi
core   +1 more source

Detrital-zircon geochronology and provenance of the Ocloyic synorogenic clastic wedge, and Ordovician accretion of the Argentine Precordillera terrane [PDF]

open access: yes, 2015
The Precordillera terrane in northwestern Argentina is interpreted to be anexotic (Laurentian) continental fragment that was accreted to western Gondwanaduring the Ordovician. One prominent manifestation of the subductionand collision process is a Middle?
Astini, Ricardo Alfredo   +3 more
core   +1 more source

Neoproterozoic Anatexis of 2.9 Ga Old Granitoids in the Goiás-Crixás Archean Block, Central Brazil: Evidence From New SHRIMP U-Pb Data and Sm-Nd Isotopes [PDF]

open access: yesGeologia USP. Série Científica, 2003
The first SHRIMP U-Pb ages for granitoid rocks from the southern part of the Goiás-Crixás Archean Block (Caiçara andUvá complexes) are presented and discussed in combination with Sm-Nd isotopic data in order to elucidate the main aspectsof the geological
Márcio Martins Pimentel   +5 more
doaj  

Geochronological and geochemical characteristics of the Caledonian Longquan pluton in southern Zhejiang, and their geological significance

open access: yesDizhi lixue xuebao, 2022
The Longquan pluton is a rare Caledonian granitic rock mass in southern Zhejiang. Studies on the Longquan pluton using petrology, geochemistry, and chronology were conducted in this paper, which reveal that it is composed of granite-monzogranite ...
LIU Yuandong   +5 more
doaj   +1 more source

U-Pb SHRIMP ages of Neoproterozoic (Sturtian) glaciogenic Pocatello Formation, southeastern Idaho

open access: yesGeology, 2004
Three stratigraphically well defined rocks from the glaciogenic Scout Mountain Member, Neoproterozoic Pocatello Formation, southern Idaho, yielded sensitive, high-resolution ion-microprobe (SHRIMP) U-Pb zircon ages that constrain the age of the upper diamictite and its cap carbonate to between ca. 710 and 667 Ma.
Fanning, Christopher, Link, Paul K.
openaire   +2 more sources

Microssonda Iônica de Alta Resolução e de Alta Sensibilidade (SHRIMP IIe/MC) do Instituto de Geociências da Universidade de São Paulo, Brasil: método analítico e primeiros resultados

open access: yesGeologia USP. Série Científica, 2014
Este trabalho apresenta as características de espectrômetro de massa de íons secundários acoplado com uma Microssonda Iônica de Alta Resolução, do tipo SHRIMP IIe/MC, instalada no Instituto de Geociências da Universidade de São Paulo (IGc-USP), bem como ...
Kei Sato   +5 more
doaj  

Zircon ages in granulite facies rocks: decoupling from geochemistry above 850 °C? [PDF]

open access: yes, 2018
Granulite facies rocks frequently show a large spread in their zircon ages, the interpretation of which raises questions: Has the isotopic system been disturbed? By what process(es) and conditions did the alteration occur?
A Boriani   +120 more
core   +1 more source

Comparison of SHRIMP U-Pb dating of monazite and zircon

open access: yesChinese Science Bulletin, 2004
Monazite dating is an important technique in geochronological studies. However, monazite U-Pb dating by SHRIMP is much less popular than zircon in geochronological applications. This paper compares the results of SHRIMP U-Pb dating of monazites and zircons separated from two granite samples, indicating that monazite SHRIMP U-Pb dating at the Beijing ...
openaire   +1 more source

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