Results 1 to 10 of about 6,544,459 (237)

A new method integrating high-precision U–Pb geochronology with zircon trace element analysis (U–Pb TIMS-TEA)

Geochimica et Cosmochimica Acta, 2010
Increased precision in isotope-dilution thermal ionization mass spectrometry (ID-TIMS) U–Pb geochronology has revealed age complexities in zircon populations that require new tools for understanding how the growth of zircon is related to geologic processes.
Schoene, B., Latkoczy, C., Schaltegger, Urs, Günther, D.   +3 more
openaire   +3 more sources

U-Pb age of the Baltoro granite, northwest Himalaya, and implications for monazite U-Pb systematics

Geology, 1989
The Baltoro granite is a major late- to post-tectonic plutonic phase of the Karakoram batholith of the northwest Himalaya in northern Pakistan. U-Pb zircon analyses indicate both emplacement at 21.0 ±0.5 Ma and significant Precambrian zircon inheritance.
Randall R. Parrish, Rein Tirrul
openaire   +1 more source

Petrogenesis of the Lijiagou spodumene pegmatites in Songpan-Garze Fold Belt, West Sichuan, China: Evidence from geochemistry, zircon, cassiterite and coltan U-Pb geochronology and Hf isotopic compositions

, 2020
Spodumene and other pegmatites in the Lijiagou area are located in the central Songpan-Garze Fold Belt (SGFB), West Sichuan. These pegmatites are hosted within the giant Songpan-Garze polymetallic belt.
Guangchun Fei, J. Menuge, Yunqiang Li, Jiyi Yang, Yun Deng, Changsheng Chen, Yufan Yang, Zhengxi Yang, Liye Qin, Luo Zheng, Wenchun Tang   +10 more
semanticscholar   +1 more source

Staurolite as an isotopic U–Pb geochronometer

Geology of Ore Deposits, 2016
A new approach is suggested for measuring the real U–Pb and Pb–Pb ages of rock-forming metamorphic staurolite. Previously, two approaches have been used for this purpose: (1) measurement of the lead isotopic compositions, uranium and lead contents in leach substance as a product of the step-leaching technique; age is calculated by plotting the Pb–Pb ...
L. K. Levskii, A. F. Lobikov
openaire   +1 more source

Interpretation of discordant U‐Pb zircon ages: An evaluation

Journal of Metamorphic Geology, 1997
The most widely used technique for the determination of high precision mineral growth ages in igneous and metamorphic rocks is dating of zircons with the U‐Pb method. The interpretation of these ages, particularly in metamorphic settings, is hampered by an incomplete understanding of the common phenomenon of partial Pb‐loss in zircon.
Mezger, Klaus, KROGSTAD, E. J.
openaire   +1 more source

SA01 – A Proposed Zircon Reference Material for Microbeam U‐Pb Age and Hf‐O Isotopic Determination

Geostandards and Geoanalytical Research, 2019
A new natural zircon reference material SA01 is introduced for U‐Pb geochronology as well as O and Hf isotope geochemistry by microbeam techniques. The zircon megacryst is homogeneous with respect to U‐Pb, O and Hf isotopes based on a large number of ...
Chao Huang, Hao Wang, Jin-Hui Yang, J. Ramezani, Chuan Yang, Shao‐Bing Zhang, Yueheng Yang, X. Xia, Lianjun Feng, Jie Lin, Tiantian Wang, Q. Ma, Huaiyu He, Liewen Xie, Shitou Wu   +14 more
semanticscholar   +1 more source

U-Pb AGE OF THE CHATTANOOGA SHALE

Geological Society of America Bulletin, 1960
An attempt was made to date the upper black unit of the Gassaway member of the Chattanooga shale which carries the maximum U/Pb ratio. Three samples were analyzed by isotopic dilution techniques. The U238-Pb206 ages on all 3 samples agreed within their experimental errors. The average of the two samples with reasonably small errors gave an apparent age
J. C. COBB, J. L. KULP
openaire   +1 more source

Air abrasion experiments in U-Pb dating of zircon

Chemical Geology, 1986
Abstract Air abrasion of zircon grains can remove metamict material that has lost radiogenic Pb and zircon overgrowths that were added during younger events and thereby improve the precision of the age measurements and permit closer estimates of the original age.
S.S. Goldich, Lynn B. Fischer
openaire   +1 more source

LA-ICP-MS U Pb geochronology of wolframite by combining NIST series and common lead-bearing MTM as the primary reference material:Implications for metallogenesis of South China

, 2020
Direct dating of W and W Sn deposits by wolframite is more reliable relatively to gangue mineral and important for understanding their timing and genesis. However, such analysis still lacks of homogeneous wolframite standard recently.
Yanwen Tang, Kai Cui, Zhengfu Zheng, Jianfeng Gao, Junjie Han, Jie-hua Yang, Liang Liu   +6 more
semanticscholar   +1 more source

The three-dimensional UPb method: Generalized models and implications for UPb two-stage systematics

Chemical Geology, 1992
Four forms of the three-dimensional UPb method established so far are physically generalized within the framework of a UPb two-stage evolution. Such a generalization provides an explicit insight into the principle of conventional UPb discordia dating. Its implications for both UPb geochronology and Pb isotopic geology are illustrated for whole-rock
openaire   +1 more source