Results 41 to 50 of about 2,657,206 (280)

Stable oxygen and carbon isotope compositional fields for skeletal and diagenetic components in New Zealand Cenozoic nontropical carbonate sediments and limestones: A synthesis and review [PDF]

, 1996
The stable oxygen isotope composition (δ18O) of a precipitated carbonate depends mainly on the isotope composition, salinity, and temperature of the host fluid, whereas the stable carbon isotope composition (δ13C) reflects the source of CO2 for ...
Nelson, Campbell S., Campbell S. Nelson, Smith, Abigail M., Abigail M. Smith   +3 more
core   +1 more source

Hf isotope composition of zircons and implication for the petrogenesis of Yajiangqiao granite, Hunan Province, China

Chinese Science Bulletin, 2003
In the peralumineous granite of Yajiangqiao zircon population can be divided into two groups (i.e. Zircon I and Zircon II), which were formed in magmatic chamber and in emplacement place, respectively. The Hf isotope compositions of two stages of zircon show that the host magma was essentially derived from crustal material by melting.
Xiang Wang, W. L. Griffin, Zhicheng Wang, Xinmin Zhou   +3 more
openaire   +2 more sources

Petrologic and geochronological constraints on the polymetamorphic evolution of the collisional granites, Araçuaí Orogen (SE Brazil)

Anais da Academia Brasileira de Ciências, 2021
Collisional granites of the Araçuaí Orogen, southeastern Brazil, record petrological and geochronological evidence for multiple crustal melting during the orogeny evolution. U-Pb zircon data indicate that these granites crystallized at 586 ± 2 M.y.
SANDRO MAURI, MARILANE G. MELO, CRISTIANO LANA, RODSON A. MARQUES   +3 more
doaj   +1 more source

The effect of sediment recycling in subduction zones on the Hf isotope character of new arc crust, Banda arc, Indonesia [PDF]

, 2011
A large portion of Earth's crust is formed at convergent plate boundaries that are accompanied by the subduction of sediments that can contain evolved crust-derived detritus.
O. Nebel, W. van Westrenen, Davies, G.R.; id_orcid, van Westrenen, W.; id_orcid, Davies, G.R., van Westrenen, W., P.Z. Vroon, Iizuka, T., T. Iizuka, Nebel, O., Vroon, P.Z.; id_orcid, Vroon, P.Z., G.R. Davies   +12 more
core   +1 more source

Hf isotopic compositions of the Hawaii Scientific Drilling Project Core and the source mineralogy of Hawaiian basalts [PDF]

Geophysical Research Letters, 1999
A large suite of Mauna Kea basalts from the Hawaii Scientific Drilling Project core show a progressive enrichment in radiogenic Hf with time (ϵHf = +11.4 to +13.1) well‐correlated with the increasingly radiogenic character of Nd. The alkali basalts erupted at the termination of the Mauna Kea stage are isotopically indistinguishable from the underlying ...
Janne Blichert‐Toft, Francis Albarède
openaire   +1 more source

The continental record and the generation of continental crust [PDF]

, 2012
Continental crust is the archive of Earth history. The spatial and temporal distribution of Earth's record of rock units and events is heterogeneous; for example, ages of igneous crystallization, metamorphism, continental margins, mineralization, and ...
Hawkesworth, Chris, Cawood, Peter Anthony, Hawkesworth, C. J., Dhuime, B., P.A. Cawood, Dhuime, Bruno Philippe Marcel, Cawood, P. A., C.J. Hawkesworth, B. Dhuime   +8 more
core   +1 more source

The isotopic composition of methane in the stratosphere : high-altitude balloon sample measurements [PDF]

, 2011
The isotopic composition of stratospheric methane has been determined on a large suite of air samples from stratospheric balloon flights covering subtropical to polar latitudes and a time period of 16 yr.
Brass, Marc, Engel, A., Röckmann, Thomas, A. Engel, Borchers, Reinhard, T. Röckmann, M. Brass, Brass, M., Engel, Andreas, Röckmann, T., Borchers, R., R. Borchers   +11 more
core   +2 more sources

The Size and Emergence of Geochemical Heterogeneities in the Hawaiian Mantle Plume Constrained by Sr‐Nd‐Hf Isotopic Variation Over ∼47 Million Years

Geochemistry, Geophysics, Geosystems, 2018
The Hawaiian‐Emperor chain is the ∼6,000 km long surface expression of the deeply sourced Hawaiian mantle plume active over the past ∼81 Myr. The Hawaiian Islands (81–47 Ma) show only Kea compositions.
L. N. Harrison, D. Weis
doaj   +1 more source

Zircon U-Pb age, trace element and Hf isotope composition of Sepon Au-Cu deposit, Laos: tectonic and metallogenic implications

China Geology, 2018
: The Truong Son Fold Belt, located at the northeastern margin of the Indochina Block, is considered to be tectonically linked to the subduction of the Paleotethys Ocean and subsequent collision. Sepon is one of the most important super large deposits of
Xin-yu Wang, Dian-hua Cao, Zong-qi Wang, An-jian Wang, Yu-dong Wu   +4 more
doaj   +1 more source

Reassessing the intrusive tempo and magma genesis of the late Variscan Aar batholith: U–Pb geochronology, trace element and initial Hf isotope composition of zircon

Swiss Journal of Geosciences, 2022
The Variscan orogeny was responsible for the formation of a significant volume of igneous basement throughout present-day Europe. Detailed understanding of these rocks has, however, been obfuscated by significant overprinting during younger geologic ...
Mélissa Ruiz, Urs Schaltegger, Sean P. Gaynor, Massimo Chiaradia, Jürgen Abrecht, Christian Gisler, Federico Giovanoli, Michael Wiederkehr   +7 more
doaj   +1 more source