Results 21 to 30 of about 661,854 (360)

Direct dating of mid-crustal shear zones with synkinematic allanite:new in situ U-Th-Pb geochronological approaches applied to the Mont Blanc massif [PDF]

open access: yes, 2013
International audienceDating the timing of motion on crustal shear zones is of tremendous importance for understanding the assembly of orogenic terranes.
Cenki-tok, Benedicte   +4 more
core   +3 more sources

Modeling apparent Pb loss in zircon U–Pb geochronology [PDF]

open access: yesGeochronology
The loss of radiogenic Pb from zircon is known to be a major factor that can cause inaccuracy in the U–Pb geochronological system; hence, there is a need to better characterize the distribution of Pb loss in natural samples.
G. R. Sharman, M. A. Malkowski
doaj   +1 more source

AGE AND GEODYNAMIC SETTINGS OF MIASKITE-PEGMATITES, CARBONATITES, AND Nb-Zr MINERALIZATION OF THE ILMENO-VISHNEVOGORSKY ALKALINE COMPLEX, SOUTH URAL (U-Pb AND Rb-Sr ISOTOPE DATA)

open access: yesГеодинамика и тектонофизика, 2022
The Ilmeno-Vishnevogorsky miaskite-phenite-carbonatite complex (IVС), located in the Urals folded region, is a representative of "linear type" carbonatite complexes, with which Nb-Zr deposits are associated.
I. L. Nedosekova   +3 more
doaj   +1 more source

A comparison between in situ monazite Lu–Hf and U–Pb geochronology [PDF]

open access: yesGeochronology
In complex metamorphic rocks, monazite U–Pb dates can span a wide concordant range, leading to ambiguous geological interpretations (e.g. slow protracted cooling versus multiphase growth).
A. T. De Vries Van Leeuwen   +8 more
doaj   +1 more source

Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology of Late Paleozoic to Early Mesozoic igneous rocks of the north Chilean Andes between 20° and 31°S [PDF]

open access: yes, 2014
Indexación: Web of Science; ScieloABSTRACT. U-Pb zircon geochronological data provide record of about 130 Ma of igneous activity in the Andes of northern Chile, which extended episodically from the latest Early Carboniferous to Early Jurassic (328-194 Ma)
Maksaev, Víctor   +2 more
core   +1 more source

Extensional faulting on Tinos island, Aegean sea, Greece: How many detachments? [PDF]

open access: yes, 2007
Zircon and apatite fission track (ZFT and AFT) and (U-Th)/He, 40Ar/39Ar hornblende, and U-Pb zircon ages from the granites of Tinos Island in the Aegean Sea, Greece, suggest, together with published ZFT data, that there are three extensional detachments ...
Altherr   +79 more
core   +3 more sources

U‐Pb age of the Yxsjöberg Tungsten‐Skarn deposit, Sweden

open access: yesGFF, 1994
Abstract The Yxsjoberg scheelite‐skam deposit of western Bergslagen (south‐central Sweden) formed in Palaeoproterozoic time when aqueous fluids migrating along lithologic discontinuities replaced limestones in acid volcanic rocks. The age of the mineralization and, thus, the source of the fluids are controversial.
Romer, R., Öhlander, B.
openaire   +4 more sources

Calibrating chemical abrasion: Its effects on zircon crystal structure, chemical composition and U Pb age

open access: yesChemical Geology, 2019
The present sub-permil precision of single zircon chemical abrasion, isotope-dilution, thermal ionisation mass spectrometry (CA-ID-TIMS) U Pb dates often reveals age dispersions that are outside of analytical uncertainty.
P. Widmann, J. Davies, U. Schaltegger
semanticscholar   +1 more source

U–Pb zircon ages from the Spontang Ophiolite, Ladakh Himalaya

open access: yesJournal of the Geological Society, 2001
The Spontang Ophiolite in the Ladakh Himalaya consist of a thrust sheet of upper mantle and oceanic crustal rocks obducted onto the northern passive continental margin of India during the late Cretaceous. Precise isotopic ages of Himalayan ophiolites are presently unavailable. U–Pb dating of zircons from a dioritic segregation in the high-level gabbros
Pedersen, R, Searle, M, Corfield, R
openaire   +1 more source

A new U-Pb age for shock-recrystallised zircon from the Lappajärvi impact crater, Finland, and implications for the accurate dating of impact events

open access: yesGeochimica et Cosmochimica Acta, 2019
Accurate and precise dating of terrestrial impact craters is a critical requirement for correlating impacts with events such as mass extinctions. A number of isotopic systems have been applied to impact chronology but it is important to understand what ...
G. Kenny   +7 more
semanticscholar   +1 more source

Home - About - Disclaimer - Privacy