Screening criteria for reliable U–Pb geochronology and oxygen isotope analysis in uranium-rich zircons: A case study from the Suzhou A-type granites, SE China

Gao, Yu Ya; Li, Xian Hua; Griffin, William L.; O’Reilly, Suzanne Y.; Wang, Ya Fei

doi:10.1016/j.lithos.2014.02.002

Cited by 103 publications

(35 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It should be mentioned that the Th-U concentrations are below values where zircon damage would be observed (Gao et al 2014;White and Ireland 2012), and, as can be seen in Fig. 4, are actually optimal and give less deviation.…”

Section: Syenite Of Podzamek (Podz2)mentioning

confidence: 75%

Multiphase magmatic activity in the Variscan Kłodzko–Złoty Stok intrusion, Polish Sudetes: evidence from SHRIMP U–Pb zircon ages

Jokubauskas¹,

Bagiński²,

Macdonald³

et al. 2017

Int J Earth Sci (Geol Rundsch)

View full text Add to dashboard Cite

The Kłodzko-Złoty Stok intrusion (KZSI), located in the NE part of the Bohemian Massif of Central Europe, has preserved records of the magmatic and tectonic activity of the Variscan orogeny in the Sudetes. KZSI is extraordinarily complex texturally, and shows a very wide range of chemical, isotopic and mineralogical compositions which indicates a complex, multiphase history of intrusion. New SHRIMP U-Pb zircon ages provide evidence of two magmatic episodes with a distinctive hiatus between them at ~ 326-308 Ma. The youngest dated zircons (303.8 ± 3.8/4.2 Ma) are from the Laski leucocratic hornblende-biotite monzogranite and mark a short interval of post-collisional reactivation of the magma system. Zircons from a biotite-hornblende diorite sheet from the northern part of KZSI yielded an age of 349 ± 3.4/3.7 Ma, interpreted as indicating the initial phase of an early Carboniferous, multi-pulse episode. The evolution of the magmatic system can be tied to a 334.4 ± 2.9/3.3 Ma zircon age for melanocratic syenites from Podzamek which represent lamprophyric melt. Based on textural and compositional data and field relationships we interpret the intrusion as having been tilted post-emplacement towards the NW. This, together with the new dating results, ties the early Carboniferous episode of KZSI activity and the Jawornik granitoids (5 km to the SE) to the same magmatic system and arguably to bentonites of the Paprotnia beds (5 km to the NW), all representing different levels of such a system. The newly estimated late Carboniferous age from Laski ties part of the KZSI to other late Carboniferous Sudetic intrusions and late Carboniferous-Permian volcanism.

show abstract

Section: Syenite Of Podzamek (Podz2)mentioning

confidence: 75%

Multiphase magmatic activity in the Variscan Kłodzko–Złoty Stok intrusion, Polish Sudetes: evidence from SHRIMP U–Pb zircon ages

Jokubauskas¹,

Bagiński²,

Macdonald³

et al. 2017

Int J Earth Sci (Geol Rundsch)

View full text Add to dashboard Cite

show abstract

“…Thus, in addition to calculating the total dose, it is desirable to estimate the amount of actual damage in a domain of interest. For zircons below the first percolation point, the amount of preserved radiation damage has been estimated from broadening and shifting toward lower wavenumber of Raman bands as measured in reflectance mode at 1 μm-scale Nasdala et al 2001bNasdala et al , 2003Pidgeon et al 2013;Gao et al 2014;Wang et al 2014).…”

Section: Radiation Damage In Zirconmentioning

confidence: 99%

“…The increasing use of in situ techniques for spot analysis of sub-domains of a zircon reinforces the importance of evaluating the localized effects of radiation damage, which can facilitate elemental and isotopic exchange and cause erroneous results for measurements of U-Pb age White and Ireland 2012); oxygen isotope ratios (Valley et al 1994;Valley 2003;Cavosie et al 2005;Booth et al 2005; Gao et al 2014; Wang et al 2014), and trace elements Commonly achieved spatial resolution and detection range for microanalysis. APM = atom probe microscopy; APT = atom probe tomography; EDS = energy-dispersive X-ray spectrometry; EELS = electron energy loss spectroscopy; EPMA = electron-probe microanalysis; SEM = scanning electron microscopy; SIMS = secondary ion mass spectrometry; (S)TEM = (scanning) transmission electron microscopy; WDS = wavelength-dispersive X-ray spectrometry.…”

Section: Introductionmentioning

confidence: 99%

Nano- and micro-geochronology in Hadean and Archean zircons by atom-probe tomography and SIMS: New tools for old minerals

Valley

Reinhard

Cavosie

et al. 2015

American Mineralogist

116

View full text Add to dashboard Cite

Atom-probe tomography (APT) and secondary ion mass spectrometry (SIMS) provide complementary in situ element and isotope data in minerals such as zircon. SIMS measures isotope ratios and trace elements from 1-20 μm spots with excellent accuracy and precision. APT identifies mass/ charge and three-dimensional position of individual atoms (±0.3 nm) in 100 nm-scale samples, volumes up to one million times smaller than SIMS. APT data provide unique information for understanding element and isotope distribution; crystallization and thermal history; and mechanisms of mineral reaction and exchange. This atomistic view enables evaluation of the fidelity of geochemical data for zircon because it provides new understanding of radiation damage, and can test for intracrystalline element mobility. Nano-geochronology is one application of APT in which Pb isotope ratios from sub-micrometer domains of zircon provide model ages of crystallization and identify later magmatic and metamorphic reheating.Based on SEM imaging and SIMS analysis, 11 needle-shaped specimens ~100 nm in diameter were sampled from one Archean and two Hadean zircons by focused ion-beam milling and analyzed with APT. The three-dimensional distribution of Pb and nominally incompatible elements (Y, REEs) differs at the atomic scale in each zircon. Zircon JH4.0 (4.007 Ga, Jack Hills, Western Australia) is homogeneous in Pb, Y, and REEs. In contrast, Pb and Y and REEs are clustered in sub-equant ~10 nm diameter domains, spaced 10-40 nm apart in zircons ARG2.5 (2.542 Ga, Grouse Creek Mountains, Utah) and JH4.4 (4.374 Ga, Jack Hills). Most clusters are flattened parallel to (100) or (010). U and Th are not collocated with Pb in clusters and appear to be homogeneously distributed in all three zircons. The analyzed domains experienced 4 to 8 × 10 15 α-decay events/mg due to U and Th decay and yet all zircons yield U-Pb ages by SIMS that are better than 97% concordant, consistent with annealing of most radiation damage. The 207 Pb/ 206 Pb ratios for the 100 nm-scale specimens measured by APT average 0.17 for ARG2.5, 0.42 for the JH4.0, and 0.52 for JH4.4. These ratios are less precise (±10-18% 2σ) due to the ultra-small sample size, but in excellent agreement with values measured by SIMS (0.1684, 0.4269, and 0.5472, respectively) and the crystallization ages of the zircons. Thus Pb in these clusters is radiogenic, but unsupported, meaning that the Pb is not spatially associated with its parent isotopes of U and Th. For the domain outside of clusters in JH4.4, the 207 Pb/ 206 Pb ratio is 0.3, consistent with the SIMS value of 0.2867 for the zircon overgrowth rim and an age of 3.4 Ga. In ARG2.5, all Pb is concentrated in clusters and there is no detectable Pb remaining outside of the clusters. The Pb-Y-REE-rich clusters and lack of correlation with U in ARG2.5 and JH4.4 are best explained by diffusion of Pb and other elements into ~10 nm amorphous domains formed by α-recoil. Diffusion distances of ~20 nm for these elements in crystalline zircon are consistent with heatin...

show abstract

“…Spectra of the zircon standardsin Temora, Plesovice, and 91500 with U concentration are also displayed for comparison. They experienced very few alpha decay/recoil events (White & Ireland, ; Gao et al ., ). In these spectra of zircon standards, peaks are well defined and sharp.…”

Section: Analytical Resultsmentioning

confidence: 97%

U–Pb geochronology and Raman spectroscopy of zircons from the granites in the Xihuashan and Tieshanlong Deposit: Implications for W‐Sn mineralization in Southern Jiangxi Province, South China

et al. 2019

View full text Add to dashboard Cite

The Xihuashan and Tieshanlong tungsten deposit is an important large quartz vein‐type W‐polymetallic deposit in the southern Jiangxi Province, eastern Nanling Range. Zircon U–Pb analyses of representative ore‐forming granites from the Xihuashan and Tieshanlong tungsten deposit yield ages of 146.3 ± 2.9 Ma and 146.0 ± 3.8 Ma, respectively. According to the zircon Raman spectroscopy, these granitic rocks are disturbed by different degrees of hydrothermal alteration, whereas most zircons exhibit primary oscillatory zoning and Th/U ratios in the range of magmatic zircon, which means the analysis results represent the crystallization age of metallogenetic granitic assemblages. In combination with regional geological data, it is suggested that the Late Jurassic is probably another important episode of granitic magmatism and W‐Sn mineralization in southern Jiangxi Provinces, even South China.

show abstract

Screening criteria for reliable U–Pb geochronology and oxygen isotope analysis in uranium-rich zircons: A case study from the Suzhou A-type granites, SE China

Cited by 103 publications

References 59 publications

Multiphase magmatic activity in the Variscan Kłodzko–Złoty Stok intrusion, Polish Sudetes: evidence from SHRIMP U–Pb zircon ages

Multiphase magmatic activity in the Variscan Kłodzko–Złoty Stok intrusion, Polish Sudetes: evidence from SHRIMP U–Pb zircon ages

Nano- and micro-geochronology in Hadean and Archean zircons by atom-probe tomography and SIMS: New tools for old minerals

U–Pb geochronology and Raman spectroscopy of zircons from the granites in the Xihuashan and Tieshanlong Deposit: Implications for W‐Sn mineralization in Southern Jiangxi Province, South China

Contact Info

Product

Resources

About