Results 31 to 40 of about 157,575 (214)
Crustal evolution of the western part of the Archean Gavião Block, São Francisco Craton, based on U-Pb, Sm-Nd and Rb-Sr evidence [PDF]
Geologia USP. Série Científica, 2013 The western part of the Gavião Block (São Francisco Craton) is one of the oldest fragments of the South American Platform. It comprises the Riacho de Santana Gneissic Migmatitic complex, the Santa Isabel complex and the Riacho de Santana greenstone belt.
Natali da Silva Barbosa +3 more
doaj +1 more source
Geochimica et Cosmochimica Acta, 2008 Abstract Precise U–Pb ages, determined with double spike ( 202 Pb– 205 Pb) thermal ionization m1ass spectrometry, are reported for angrites Angra dos Reis (AdoR), Lewis Cliff 86010 (LEW), and D’Orbigny. Nineteen of 23 acid-washed pyroxene fractions from these meteorites and whole rock fractions from D’Orbigny contain between 0.5 and 1.3 pg of total ...
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Frontiers in Earth Science, 2022 Emerging evidence suggests that U-Pb and Lu-Hf ages of sedimentary apatite group minerals are often younger than their biostratigraphic ages. However, U-Pb dating of exquisitely preserved carbonate fluorapatite (CFA) is rare.
Jérémie Aubineau +7 more
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Sensitive High Resolution Ion Microprobe (SHRIMP IIe/MC) of the Institute of Geosciences of the University of São Paulo, Brazil: analytical method and first results [PDF]
Geologia USP. Série Científica, 2014 This paper presents the characteristics of the high resolution secondary ion mass spectrometer coupled with an Ion Micro - probe (SHRIMP IIe/MC), installed at the Institute of Geosciences of the University of São Paulo (IGc-USP), as well as the ...
Kei Sato +6 more
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Frontiers in Earth ScienceA series of NE-to E-trending ductile shear zones are widely distributed in the Khondalite Belt, a Paleoproterozoic collisional orogen in the North China Craton.
Hengzhong Qiao +3 more
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Yankuang ceshi, 2022 BACKGROUND The Changjiang uranium ore field in the southern margin of the Zhuguangshan complex pluton is a typical granite-type uranium ore field in China. Zircon U-Pb dating has been used to date ore-bearing granites. However, due to the high content of
CHEN Yan +6 more
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A relational database of global U–Pb ages
Geoscience Frontiers, 2018 Abstract Enhanced understanding of how sampling techniques affect estimates of the global U–Pb age-distribution have, in turn, constrained U–Pb database design. Recent studies indicate that each continent has a unique age-distribution, as determined by zircon ages dated by the U–Pb isotope method.
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Titanite U-Pb dating by LA-Quadrupole-ICP-MS: analytical procedures and applications to Rhyacian metamorphic rocks of the Southeastern Guiana Shield [PDF]
Anais da Academia Brasileira de CiênciasWe present a comprehensive set of LA-Q-ICP-MS U-Pb ages on titanite standards (Tory Hill, Khan, Mud Tank, and CKHB titanites) together with samples from the Southeastern Guiana Shield, as a geological application of the method implemented at the Pará-Iso
JOÃO ALBERTO E. PINTO +3 more
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Westward Growth of Laurentia by Pre–Late Jurassic Terrane Accretion, Eastern Oregon and Western Idaho, United States [PDF]
, 2015 New U-Pb and Sm-Nd data from the Blue Mountains province, eastern Oregon and western Idaho, clarify terrane correlations and regional evolution of the western Laurentian plate margin during Mesozoic time.
Dorsey, Rebecca J. +5 more
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Precise U-Pb zircon ages and geochemistry of Jurassic granites, Ellsworth-Whitmore terrane, central Antarctica [PDF]
, 2016 The Ellsworth-Whitmore Mountain terrane of central Antarctica was part of the early Paleozoic amalgamation of Gondwana, including a 13,000 m section of Cambrian–Permian sediments in the Ellsworth Mountains deposited on Grenville-age crust.
Craddock, John P. +7 more
core +1 more source