نتایج جستجو برای: sr and nd isotopes

تعداد نتایج: 16837175  

Journal: :Ground water 2007
Elizabeth L Brinck Carol D Frost

Water introduced to surface drainages, such as agricultural and roadway runoff, mine drainage, or coalbed natural gas (CBNG)-produced water, potentially can be of environmental concern. In order to mitigate potential environmental effects, it may be important to be able to trace water discharged to the surface as it infiltrates and interacts with near-surface aquifers. We have chosen to study w...

2007
Peter B. Kelemen Gene Yogodzinski

Streck et al. (2007) state that primitive andesite lavas (Mg# > 0.6; 53–63 wt% SiO 2 ) from Mt. Shasta are not primary melts, but instead are mixtures of evolved, high-Sr/Y, low-Mg# dacite with primary, low-Sr/Y, high-Mg# basalt. They propose that this mixing forms primitive andesites worldwide, and they dismiss the idea that primitive andesite is an end member in arc magmatism. Magma mixing is...

2009
J. D. Gleason D. J. Thomas T. C. Moore J. D. Blum R. M. Owen B. A. Haley

[1] Strontium and neodymium radiogenic isotope ratios in early to middle Eocene fossil fish debris (ichthyoliths) from Lomonosov Ridge (Integrated Ocean Drilling Program Expedition 302) help constrain water mass compositions in the Eocene Arctic Ocean between !55 and !45 Ma. The inferred paleodepositional setting was a shallow, offshore marine to marginal marine environment with limited connect...

2008
Matthew J. Kohn

Rayleigh distillation models are developed to describe theoretical growth zoning of Lu, Hf, Rb, Sr, Sm, and Nd in typical garnet crystals from metapelites and metabasites. Effects of diffusion-limited transport within the matrix and intracrystalline diffusion are also considered qualitatively. Theoretical zoning profiles show strong depletions of Lu in garnet rims compared to cores, but virtual...

2014
Verena Schoepf Malcolm T. McCulloch Mark E. Warner Stephen J. Levas Yohei Matsui Matthew D. Aschaffenburg Andréa G. Grottoli

Coral skeletal boron isotopes have been established as a proxy for seawater pH, yet it remains unclear if and how this proxy is affected by seawater temperature. Specifically, it has never been directly tested whether coral bleaching caused by high water temperatures influences coral boron isotopes. Here we report the results from a controlled bleaching experiment conducted on the Caribbean cor...

2009
Elizabeth Brinck Carol Frost

Please cite this article in press as: Brinck, E., Fr doi:10.1016/j.apgeochem.2009.09.001 Gypsum and S are applied to soils being irrigated with Na–HCO3 dominated coalbed natural gas (CBNG) produced water to protect soil structure and fertility. Wyoming law requires beneficial use of produced water and irrigation with CBNG produced water in the semi-arid Powder River Basin is becoming more commo...

2007
D. A. Papanastassiou

We report Sr isotope anomalies in two Ca·Al-rich inclusions (EKl-4-1 and Cl) of the Allende meteoritewhichalsocontainanomaliesin 0, Mg, Ca, Ba, Nd and Sm. The Sr effects correspond to 84 Sr or 88 Sr deficits of 3.2"too and 0.8%o or to 86 Sr excesses of 1.6%o and 0.4"too. Although it cannot be ascertained in which isotope the anomalies reside, arguments based on the 8 7 Sr abundance indicate tha...

2005
B. A. Wiegand O. A. Chadwick P. M. Vitousek J. L. Wooden

[1] Biogeochemical processes fractionate Ca isotopes in plants and soils along a 4 million year developmental sequence in the Hawaiian Islands. We observed that plants preferentially take up Ca relative to Ca, and that biological fractionation and changes in the relative contributions from volcanic and marine sources produce a significant increase in Ca in soil exchangeable pools. Our results i...

2015
Setsuo Nomura Bo Liang Shuang Liu Lina Guo Shin-ichi Ohshima Takayuki Kurosu Takeshi Ikegami Ken Hagimoto Alexander M. Akulshin Teruyuki Kinno Miyoko O. Watanabe Koichi Mizushima

Soil contamination by nuclear accidents has led to a resurgence of interest in microberadionuclide interactions. Soil fungi accumulate radioactive elements from contaminated soil, and it has been hypothesized that this may alter the availability of radionuclides to plants and alter their movement in particular areas. This study intended to demonstrate how soil saprotrophic fungi accumulated Cs ...

Journal: :Minerals 2021

The geochemistry on Holocene lavas from the Jingpohu volcanic field in NE China are compared with other Cenozoic across back-arc rift of China, order to constrain their enriched mantle sources. within comprise two separate “Crater Forest” (CF) and “Frog Pool” (FP) areas. FP have lower MgO, CaO, heavy rare earth elements higher Al2O3, Na2O, K2O, large-ion lithophile than CF lavas. Yet, both shar...

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