Results 41 to 50 of about 157,575 (214)

U-Pb chronology of the Solar System's oldest solids with variable 238 U/ 235 U

, 2016
Accurate determination of the absolute ages of the oldest Solar System objects - chondrules and Ca-Al-rich inclusions (CAIs), requires knowledge of their 238U/235U ratios.
Amelin, Yuri, Iizuka, Tsuyoshi, Ireland, Trevor, Jacobsen, Stein, Kaltenbach, Angela, Petaev, Michail, Stirling, Claudine H   +6 more
core   +1 more source

Evaluation of the decay constant of uranium 235 from lead isotope ratios [PDF]

, 1966
The decay constant of U^(235) has been evaluated from the radiogenic Pb^(207)/Pb^(206) ratios of several cogenetic fractions of zircon and uranothorite, analyzed by conventional mass spectrometric methods.
Banks, Philip O., Silver, Leon T.
core   +1 more source

U‐Pb Geochronology of Paleosol Carbonate Cements by LA‐ICP‐MS: A Proof of Concept and Strategy for Dating the Terrestrial Record

Geochemistry, Geophysics, Geosystems
This study investigates the potential of laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) U‐Pb dating for carbonate nodules in the Late Triassic Ischigualasto Formation of northwestern Argentina.
L. E. Aguirre Palafox, A. Möller, N. M. McLean, G. A. Ludvigson, C. E. Colombi, I. P. Montañez   +5 more
doaj   +1 more source

Distinct ^(238)U/^(235)U ratios and REE patterns in plutonic and volcanic angrites: Geochronologic implications and evidence for U isotope fractionation during magmatic processes [PDF]

, 2017
Angrites are differentiated meteorites that formed between 4 and 11 Myr after Solar Systemformation, when several short-lived nuclides (e.g., ^(26)Al-^(26)Mg, ^(53)Mn-^(53)Cr, ^(182)Hf-^(182)W) were still alive. As such, angrites are prime anchors to tie
Dauphas, Nicolas, Grove, Timothy L., Tissot, François L. H.   +2 more
core  

Provenance study of Pliocene–Pleistocene sands based on ancient detrital zircons (Alvalade basin, SW Iberian Atlantic Coast) [PDF]

, 2014
Pliocene–Pleistocene sand of the Alvalade basinwas taken fromthe sea-cliffs of SWIberia coast for a provenance study using radiometric dating. The U–Pb ages obtained revealed a wide interval ranging from Cretaceous to Archean, with predominance of ...
Albardeiro, Luis, Chichorro, Martim, Gama, Cristina, Hofmann, Mandy, Linnemann, Ulf, Pereira, M.Francisco   +5 more
core   +1 more source

U-Pb ages and Nd isotope characteristics of the lateorogenic, migmatizing microcline granites in southwestern Finland [PDF]

Bulletin of the Geological Society of Finland, 2005
U-Pb ages and whole-rock Nd isotope data have been obtained from the Paleoproterozoic lateorogenic migmatizing microcline granites of southwestern Finland.
M. Kurhila, M. Vaasjoki, I. Mänttäri, T. Rämö, M. Nironen   +4 more
doaj   +1 more source

Concordant Rb-Sr and Sm-Nd Ages for NWA 1460: A 340 Ma Old Basaltic Shergottite Related to Lherzolitic Shergottites [PDF]

, 2006
Preliminary Rb-Sr and Sm-Nd ages reported by [1] for the NWA 1460 basaltic shergottite are refined to 336+/-14 Ma and 345+/-21 Ma, respectively. These concordant ages are interpreted as dating a lava flow on the Martian surface.
Irving, A. J., Nyquist, L. E., Reese, Y. D., Shih, C-Y   +3 more
core   +1 more source

Integration of new zircon U–Pb ages with biostratigraphy to establish a high-precision age model of the Miocene Nakayama Formation on Sado Island in Central Japan

Progress in Earth and Planetary Science
The most common age constraint for the diatomaceous sediments is biostratigraphy of siliceous microfossils. Although biostratigraphy is a powerful tool to establish stratigraphy and correlate with sedimentary sequences in other sites, biostratigraphy ...
Jumpei Yoshioka, Kenji M. Matsuzaki, Sota Niki, Junichiro Kuroda, Takafumi Hirata   +4 more
doaj   +1 more source

Simultaneous Determination of U-Pb Age and Trace Elements of Zircon by Laser Ablation Sector Field Inductively Coupled Plasma-Mass Spectrometry

Yankuang ceshi
Laser ablation sector field inductively coupled plasma-mass spectrometry (LA-SF-ICP-MS) is widely applied in U-Pb dating of zircon due to its remarkable sensitivity.
Linghao ZHAO, Dongyang SUN, Mingyue HU, Jihai YUAN, Chenzi FAN, Xiuchun ZHAN   +5 more
doaj   +1 more source

SHRIMP Zircon U-Pb Dating of Mid-Pleistocene Dacite and Discussion of Relative Problems

Yankuang ceshi, 2015
K-Ar and U series disequilibria methods have been applied to geochronology research of young volcanic rocks in Tengchong, China. Previous K-Ar dating methods yielded ages of 0.013 to 17.84 Ma and isochron ages of 0.13 to 2.9 Ma in this area. The U series
LI Lin-lin, WANG Shu-bing, SHI Yu-ruo
doaj   +1 more source