نتایج جستجو برای: zircon morphology

تعداد نتایج: 149157  

2016
Sandra Piazolo Alexandre La Fontaine Patrick Trimby Simon Harley Limei Yang Richard Armstrong Julie M. Cairney

Trace elements diffuse negligible distances through the pristine crystal lattice in minerals: this is a fundamental assumption when using them to decipher geological processes. For example, the reliable use of the mineral zircon (ZrSiO4) as a U-Th-Pb geochronometer and trace element monitor requires minimal radiogenic isotope and trace element mobility. Here, using atom probe tomography, we doc...

2009
JAMES D. GLEASON GEORGE E. GEHRELS WILLIAM R. DICKINSON P. JONATHAN PATCHETT DAVID A. KRING

U–Pb ages of individual detrital zircon grains from deltaic and turbidite sandstones of the lower to middle Pennsylvanian Haymond Formation (Marathon basin, west Texas) range from 320 Ma to 3 Ga, indicating a mixed provenance broadly similar to that of Ouachita Carboniferous turbidites and related fluvio-deltaic facies of Arkansas–Oklahoma. Differences with the Ouachita assemblage are attribute...

2013
Yolanda Hedberg Jonas Hedberg Inger Odnevall Wallinder

Titanium oxide (rutile, TiO2) and zircon (ZrSiO4), known insoluble ceramic materials, are commonly used for coatings of implant materials. We investigate the release of zirconium, titanium, aluminum, iron, and silicon from different micron-sized powders of 6 powders of natural rutile (TiO2) and zircon (ZrSiO4) from a surface perspective. The investigation includes five different synthetic body ...

Journal: :Science 1996
Riggs Lehman Gehrels Dickinson

New detrital-zircon geochronologic data reveal that a through-going paleoriver connected Texas with Nevada in Late Triassic time. Sandstone from the Upper Triassic Santa Rosa Sandstone (Dockum Group) from northwestern Texas contains a detrital zircon suite nearly identical to that found in western Nevada in the Upper Triassic Osobb Formation (Auld Lang Syne Group, correlative with the Chinle Fo...

2002
D. I. Vainshtein A. Rozendaal H. W. den Hartog

Zircon appears to be a suitable medium for thermoluminescence (TL) dating of sediments from the Quaternary. TL of zircon results predominantly from internal irradiation, due to the relatively high internal concentrations of a-emitting U and Th. The internal dose predominates over the external one that is caused by the surrounding geological layers and cosmic rays. Measurement of the TL buildup ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2012
Sunshine S Abbott T Mark Harrison Axel K Schmitt Stephen J Mojzsis

Few terrestrial localities preserve more than a trace lithic record prior to ca. 3.8 Ga greatly limiting our understanding of the first 700 Ma of Earth history, a period inferred to have included a spike in the bolide flux to the inner solar system at ca. 3.85-3.95 Ga (the Late Heavy Bombardment, LHB). An accessible record of this era may be found in Hadean detrital zircons from the Jack Hills,...

2000
M Zhang E K H Salje

α-decay damage and recrystallization in natural zircon (with dose ranging from 0.06 to 23.3 × 1018 α-events g−1) were studied using polarized reflection infrared spectroscopy. The experimental results show that α-decay damage leads to a gradual decrease in reflectivity and a loss of anisotropy of IR spectra. Recrystallization of damaged zircon is found as a multi-stage process with a strong dep...

Journal: :Journal of the Japanese Association for Petroleum Technology 1991

2011
W. X. Li M. Lang C. Trautmann

Etched tracks of apatite and zircon are both widely used for the determination of the thermal history of Earth’s crust. The present understanding of the annealing process is largely limited to mathematical fits to data for etched track-lengths as a function of temperature and time. Details of the annealing of unetched, latent tracks at the atomic scale have remained elusive, as the original tra...

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