Hf-Nd isotope variation in Mariana Trough basalts: The importance of “ambient mantle” in the interpretation of subduction zone magmas

Geology ◽  
2012 ◽  
Vol 40 (6) ◽  
pp. 539-542 ◽  
Author(s):  
Jon Woodhead ◽  
Robert J. Stern ◽  
Julian Pearce ◽  
Janet Hergt ◽  
Jeff Vervoort
Keyword(s):  
Subduction Zone ◽  
Nd Isotope ◽  
Isotope Variation

Subduction-related Manipur Ophiolite Complex, Indo-Myanmar Ranges: elemental and isotopic record of mantle metasomatism

2019 ◽  
Vol 481 (1) ◽  
pp. 195-210 ◽  
Author(s):  
Oinam Kingson ◽  
Rajneesh Bhutani ◽  
S. Balakrishnan ◽  
J. K. Dash ◽  
Anil D. Shukla
Keyword(s):  
Subduction Zone ◽  
Isotope Ratios ◽  
Mantle Metasomatism ◽  
Ophiolite Complex ◽  
Rock Interaction ◽  
Nd Isotope ◽  
Mafic Rocks ◽  
Geochemical Variation ◽  
Manipur Ophiolite Complex ◽  
First Time

AbstractThis study reports, for the first time, Sr and Nd isotope ratios from the mafic rocks in the Manipur Ophiolite Complex (MOC), along with new elemental abundances to show the subduction zone influence. The initial 87Sr/86Sr ratios (for t = 127 Ma) range from 0.705230 to 0.709734. The initial 143Nd/144Nd and ɛNdt (t = 127 Ma) range from 0.512611 to 0.512900 and +2.7 to +8.3, respectively. The high field strength element (HFSE) ratios vary widely, with Nb/Ta ranging from c. 3 to 18 and Zr/Hf ranging from 20 to 41, indicating fluid–rock interaction in the presence of rutile. The correlated variation in the Nd and Sr isotope ratios and the HFSEs, including TiO2, reflects the variation in the slab-derived fluids. The light rare earth element (LREE) enriched and flat patterns yielded by the mafic rocks are modelled by varying the degree of melting of the fluid-metasomatized mantle. The subsequent influx of the slab-derived fluid at a greater depth caused the re-melting of the previously depleted wedge to produce the LREE-depleted patterns.We propose that the geochemical variation recorded in the MOC rocks indicates the changing nature of fluid metasomatism of the mantle wedge across the subduction zone with time.

Nd isotope variation across the Archaean-Proterozoic boundary in the North Ladoga Area, Russian Karelia

GFF ◽  
2005 ◽  
Vol 127 (2) ◽  
pp. 115-122 ◽  
Author(s):  
Dmitry Konopelko ◽  
Valery Savatenkov ◽  
Viktor Glebovitsky ◽  
Alexander Kotov ◽  
Sergei Sergeev ◽  
...  
Keyword(s):  
Nd Isotope ◽  
The North ◽  
Isotope Variation ◽  
Russian Karelia

Plagioclase weathering by mycorrhizal plants in a Ca-depleted catchment, inferred from Nd isotope ratios and REE composition

2017 ◽  
Vol 51 (6) ◽  
pp. 537-550
Author(s):  
Tasuku Akagi ◽  
Tomohiro Miura ◽  
Rie Takada ◽  
Kazuo Watanabe
Keyword(s):  
Isotope Ratios ◽  
Nd Isotope ◽  
Mycorrhizal Plants
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