scholarly journals Variations in Trace Element Contents and Isotopic Compositions of Lower Cretaceous Carbonates from the Galicia Margin (ODP Leg 103): Reconstruction of the Paleochemistry of the Early Cretaceous Ocean

Author(s):  
S. Clauser ◽  
M. Renard ◽  
G. Richebois
2018 ◽  
Vol 1 (1) ◽  
pp. 1-13

Background: Thyroid cancer is an internationally important health problem. The aim of this exploratory study was to evaluate whether significant changes in the thyroid tissue levels of Ag, Co, Cr, Fe, Hg, Rb, Sb, Sc, Se, and Zn exist in the malignantly transformed thyroid. Methods: Thyroid tissue levels of ten trace elements were prospectively evaluated in 41 patients with thyroid malignant tumors and 105 healthy inhabitants. Measurements were performed using non-destructive instrumental neutron activation analysis with high resolution spectrometry of long-lived radionuclides. Tissue samples were divided into two portions. One was used for morphological study while the other was intended for trace element analysis. Results: It was found that contents of Ag, Co, Cr, Hg, and Rb were significantly higher (approximately 12.8, 1.4, 1.6, 19.6, and 1.7 times, respectively) in cancerous tissues than in normal tissues. Conclusions: There are considerable changes in trace element contents in the malignantly transformed tissue of thyroid.


Urolithiasis ◽  
1989 ◽  
pp. 229-231
Author(s):  
J. Hofbauer ◽  
I. Steffan ◽  
H. Schwetz ◽  
G. Vujicic ◽  
O. Zechner

2016 ◽  
Vol 39 (5) ◽  
pp. 1159-1177 ◽  
Author(s):  
R. Jiménez-Ballesta ◽  
F. J. García-Navarro ◽  
S. Bravo ◽  
J. A. Amorós ◽  
C. Pérez-de-los-Reyes ◽  
...  

2011 ◽  
Vol 184 (7) ◽  
pp. 4517-4538 ◽  
Author(s):  
Uwe Buczko ◽  
Rolf O. Kuchenbuch ◽  
Walter Übelhör ◽  
Ludwig Nätscher

1997 ◽  
Vol 61 (405) ◽  
pp. 257-269 ◽  
Author(s):  
Suzanne Y. O'Reilly ◽  
D. Chen ◽  
W. L. Griffin ◽  
C. G. Ryan

AbstractThe proton microprobe has been used to determine contents of Ca, Ti, Ni, Mn and Zn in the olivine of 54 spinel lherzolite xenoliths from Australian and Chinese basalts. These data are compared with proton-probe data for Ni, Mn and Zn in the olivine of 180 garnet peridotite xenoliths from African and Siberian kimberlites. Fe, Mn, Ni and Zn contents are well-correlated; because the spinel lherzolite olivines have higher mean Fe contents than garnet peridotite olivines (average Fo89.6vs. Fo90–92) they also have lower Ni and higher Mn contents. Zn and Fe are well-correlated in garnet peridotite olivine, but in spinel peridotites this relationship is perturbed by partitioning of Zn into spinel. None of these elements shows significant correlation with temperature. Consistent differences in trace-element contents of olivines in the two suites is interpreted as reflecting the greater degree of depletion of Archean garnet peridotites as compared to Phanerozoic spinel lherzolites. Ca and Ti contents of spinel-peridotite olivine are well correlated with one another, and with temperature as determined by several types of geothermometer. However, Ca contents are poorly correlated with pressure as determined by the Ca-in-olivine barometer of Köhler and Brey (1990). This reflects the strong T-dependence of this barometer: the uncertainty in pressure (calculated by this method) which is produced by the ±50°C uncertainty expected of any geothermometer is ca ± 8 kbar, corresponding to the entire width of the spinel-lherzolite field at 900–1200°C.


Author(s):  
Yue Qi ◽  
Qiang Wang ◽  
Gang-jian Wei ◽  
Xiu-Zheng Zhang ◽  
Wei Dan ◽  
...  

Diverse rock types and contrasting geochemical compositions of post-collisional mafic rocks across the Tibetan Plateau indicate that the underlying enriched lithospheric mantle is heterogeneous; however, how these enriched mantle sources were formed is still debated. The accreted terranes within the Tibetan Plateau experienced multiple stages of evolution. To track the geochemical characteristics of their associated lithospheric mantle through time, we can use mantle-derived magmas to constrain the mechanism of mantle enrichment. We report zircon U-Pb ages, major and trace element contents, and Sr-Nd isotopic compositions for Early Cretaceous and late Eocene mafic rocks in the southern Qiangtang terrane. The Early Cretaceous Baishagang basalts (107.3 Ma) are characterized by low K2O/Na2O (<1.0) ratios, arc-like trace element patterns, and uniform Sr-Nd isotopic compositions [(87Sr/86Sr)i = 0.7067−0.7073, εNd(t) = −0.4 to −0.2]. We suggest that the Baishagang basalts were derived from partial melting of enriched lithospheric mantle that was metasomatized by subducted Bangong−Nujiang oceanic material. We establish the geochemistry of the pre-collisional enriched lithospheric mantle under the southern Qiangtang terrane by combining our data with those from other Early Cretaceous mafic rocks in the region. The late Eocene (ca. 35 Ma) post-collisional rocks in the southern Qiangtang terrane have low K2O/Na2O (<1.0) ratios, and their major element, trace element, and Sr-Nd isotopic compositions [(87Sr/86Sr)i = 0.7042−0.7072, εNd(t) = −4.5 to +1.5] are similar to those of the Early Cretaceous mafic rocks. Based on the distribution, melting depths, and whole-rock geochemical compositions of the Early Cretaceous and late Eocene mafic rocks, we argue that the primitive late Eocene post-collisional rocks were derived from pre-collisional enriched lithospheric mantle, and the evolved samples were produced by assimilation and fractional crystallization of primary basaltic magma. Asthenosphere upwelling in response to the removal of lithospheric mantle induced the partial melting of enriched lithospheric mantle at ca. 35 Ma.


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