Results 71 to 80 of about 151,775 (355)

U-Pb dating of niobium minerals from the pyrochlore group (Ilmeny-Vishnevogorsky carbonatite-miaskite complex, South Urals)

open access: yesЛитосфера, 2020
The article covers the U-Pb dating of minerals belonging to the pyrochlore group from the rare-metal ore deposits of Ilmeny-Vishnevogorsky carbonatite-miaskite complex (South Urals). Individual pyrochlore crystals were dated through a new technique of in-
I. L. Nedosekova   +5 more
doaj  

Clumped-isotope palaeothermometry and LA-ICP-MS U–Pb dating of lava-pile hydrothermal calcite veins

open access: yesContributions to Mineralogy and Petrology, 2019
Calcite veins are a common product of hydrothermal fluid circulation. Clumped-isotope palaeothermometry is a promising technique for fingerprinting the temperature of hydrothermal fluids, but clumped-isotope systematics can be reset at temperatures of ...
John M. MacDonald   +8 more
semanticscholar   +1 more source

Archived U-Pb (zircon) dates from southern New Brunswick

open access: yesAtlantic Geology, 2003
U-Pb (zircon) ages for eight samples from southern New Brunswick were determined during the early 1990's as part of a regional mapping and correlation program. Although most of the dates have been subsequently quoted in the literature through personal communications, and some preliminary isochron diagrams have been incorporated in papers, the results ...
Malcolm J. McLeod   +2 more
openaire   +2 more sources

A Systematic Review of Evidence on the Clinical Effectiveness of Surveillance Imaging in Children With Medulloblastoma and Ependymoma

open access: yesPediatric Blood &Cancer, EarlyView.
ABSTRACT Surveillance imaging aims to detect tumour relapse before symptoms develop, but it's unclear whether earlier detection of relapse leads to better outcomes in children and young people (CYP) with medulloblastoma and ependymoma. This systematic review aims to identify relevant literature to determine the efficacy of surveillance magnetic ...
Lucy Shepherd   +3 more
wiley   +1 more source

Les minéralisations Cu-(Ni-Bi-U-Au-Ag) d'Ifri (district du haut Seksaoua, Maroc) : apport de l'étude texturale au débat syngenèse versus épigenèse.
The Cu---(Ni---Bi---U---Au---Ag) mineralization of Ifri (‘Haut Seksaoua' district, Morocco): contribution of a textural study to the discussion syngenetic versus epigenetic

open access: yes, 2003
The Cu ore of Ifri is a chalcopyrite stockwork hosted by Cambrian formations and was until now interpreted as a syngenetic massive sulphide deposit. Textural studies highlight two generations of pyrite early (Py I) and late (Py II) with respect to the ...
Badra, Lakhifi   +6 more
core   +4 more sources

Chemostratigraphy of Neoproterozoic carbonates: implications for 'blind dating' [PDF]

open access: yes, 2001
The delta C-13(carb) and Sr-87/Sr-86 secular variations in Neoproteozoic seawater have been used for the purpose of 'isotope stratigraphy' but there are a number of problems that can preclude its routine use.
Aharon P.   +55 more
core   +1 more source

U‐Pb dating of zircons from an impact melt of the Nördlinger Ries crater

open access: yesMeteoritics and Planetary Science, 2020
In situ U‐Pb measurements on zircons of the Ries impact crater are presented for three samples from the quarry at Polsingen. The U‐Pb data of most zircons plot along a discordia line, leading to an upper intercept of Carboniferous age (331 ± 32 Ma [2σ]).
W. Schwarz, M. Hanel, M. Trieloff
semanticscholar   +1 more source

Developmental Disorders in Children Recently Diagnosed With Cancer

open access: yesPediatric Blood &Cancer, EarlyView.
ABSTRACT Neurocognitive deficits in adult survivors of childhood cancer are well established, but less is known about developmental disorders (DD) arising shortly after cancer diagnosis. Using 2016–2019 linked Ohio cancer registry and Medicaid data, we compared DD among 324 children with cancer and 606,913 cancer‐free controls.
Jamie Shoag   +5 more
wiley   +1 more source

U-Pb dating identifies titanite precipitation in Paleogene sandstones from a volcanic terrane, East Greenland

open access: yesGeological Survey of Denmark and Greenland Bulletin, 2019
Titanite (CaTiSiO5) occurs as a rare mineral in magmatic and metamorphic rocks. It is commonly found in clastic sedimentary rocks as an accessory heavy mineral – a mineral of high density.
Rikke Weibel, Tonny B Thomsen
doaj   +1 more source

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

open access: yesYankuang 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

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