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adakitic composition

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Journal Article
Published: 01 July 2009
Journal of the Geological Society (2009) 166 (4): 725-734.
... suggests that these melts are linked to discontinuities in the subducting slab, which would facilitate upwelling of hot sub-slab asthenospheric mantle. It is demonstrated that excess heat flux arcs are sites where Sr-rich adakitic compositions are generated, and that the arc proportion erupting Sr-rich...
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Journal Article
Journal: Geology
Published: 01 June 2012
Geology (2012) 40 (6): 487-490.
... and plagioclase hygrometry of mafic eruptives from southwest Japan to demonstrate that the adakitic compositions of associated intermediate magmas are of lower crustal origin due to a decrease in the water content of parental melts, and are not generated by partial melting of the eclogitic subducting slab...
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Journal Article
Journal: Geology
Published: 01 June 2008
Geology (2008) 36 (6): 499-502.
...Leonid V. Danyushevsky; Trevor J. Falloon; Anthony J. Crawford; Sofia A. Tetroeva; Roman L. Leslie; Alicia Verbeeten Abstract We report here the compositions of primitive high-Mg adakite lavas from the Kadavu Island Group, Fiji. Two distinctive high-Mg adakite compositions are present on Kadavu...
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Journal Article
Published: 01 August 1992
Journal of the Geological Society (1992) 149 (4): 569-579.
..., but there is no obvious genetic link between them through differentiation. High-Nb basalts may also be derived from the partial melting of the subducted oceanic crust. High-Nb basalt migmatites have been found with pegmatites of adakite compositions in the exposed subduction terrain of the Catalina Schist, California...
Journal Article
Journal: Geology
Published: 01 November 1993
Geology (1993) 21 (11): 1007-1010.
... subducting beneath Zamboanga. Associated Nb-enriched basalts are thought to come from mantle metasomatized through interaction with adakitic melts. In eastern Mindanao, Pliocene-Quaternary cones and plugs of typical adakitic composition mark the trace of the Philippine fault in Surigao and north Davao...
Journal Article
Journal: Geology
Published: 01 June 2005
Geology (2005) 33 (6): 465-468.
... enrichments (K 2 O > Na 2 O) are very different from the composition of typical adakites. In addition, those K-rich adakitic rocks with the highest SiO 2 contents (>61 wt%) exhibit the lowest 87 Sr/ 86 Sr ratios and highest ε Nd values and are the oldest Cenozoic volcanic rocks exposed in the Songpan...
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Journal Article
Journal: GSA Bulletin
Published: 01 March 2011
GSA Bulletin (2011) 123 (3-4): 703-724.
... basin region (Chagres-Bayano arc) from 68 to 40 Ma. A third phase formed discrete volcanic centers across the Cordillera de Panama (Cordilleran arc) from 19 to 5 Ma. The youngest phase consists of isolated volcanic centers of adakitic composition (Adakite suite) in the Cordillera de Panama...
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Journal Article
Journal: GSA Bulletin
Published: 16 July 2019
GSA Bulletin (2019)
.../Y (23−74) ratios, typical of adakite-like geochemical features. The adakitic rocks have relatively uniform initial 87 Sr/ 86 Sr isotopic ratios (0.7043−0.7046) and ε Nd (t) values (+3.67 to +4.16), indicating derivation from similar parental magmas. The δ 56 Fe values of whole-rock samples vary from...
Journal Article
Published: 15 March 2018
Journal of the Geological Society (2018) 175 (4): 679-693.
... . Fig. 4. εHf isotopic data and Hf model age (T DM C ) probability histogram for zircons from ( a , b ) the XEG granites and ( c , d ) the Daping and Taibao adakitic samples. A total of 20 zircon grains from the granitic Sample 1362 were analysed for Hf isotopic compositions...
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Journal Article
Published: 27 July 2017
Geological Magazine (2017) 155 (8): 1684-1704.
...SHENG-YAO YU; JIAN-XIN ZHANG; SAN-ZHONG LI; DE-YOU SUN; YIN-BIAO PENG; XI-LIN ZHAO Abstract – In this study, the petrology, zircon U–Pb ages, Lu–Hf isotopic compositions, whole-rock geochemistry and Sr–Nd isotopes for newly recognized low-Mg and high-Mg adakitic rocks from the North Altun orogenic...
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Journal Article
Journal: Geology
Published: 01 January 2013
Geology (2013) 41 (1): 91-94.
... by the linear relationship of some elements ( Fig. 4 ). The Jinling-Tietongou diorites (with I Sr = 0.7052–0.7109 and ɛ Nd (t) = −4 to −15; Table DR3) and adakitic rocks elsewhere on the NCC ( Fig. 5 ) show Nd-Sr isotopic compositions much more evolved than typical adakites that have mid-oceanic ridge...
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Series: Geological Society, London, Special Publications
Published: 01 January 2008
DOI: 10.1144/SP.308.16
EISBN: 9781862395565
... rocks. Their major and trace element compositions closely resemble those of adakites and Archaean trondhjemites, tonalites and granodiorites (TTG), suggesting their young and hot slab-melt origin ( Ikeda et al. 1997 ). This paper reports the first occurrence of xenocrystic garnet and kyanite...
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Journal Article
Published: 01 July 2007
Geological Magazine (2007) 144 (4): 619-631.
... and Guojialing suites have adakitic affinity. They are enriched in LREE with high La/Yb ratios and show positive Eu anomalies. The rocks are also enriched in LILE and depleted in HFSE with high Sr/Y ratios. The Linglong granite shows very uniform Sr–Nd isotopic compositions with initial 87 Sr/ 86 Sr ratios...
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Journal Article
Published: 01 January 2002
European Journal of Mineralogy (2002) 14 (1): 25-36.
... an interconnected network along mineral grain boundaries of high-Mg#, low-Y andesitic glass with major and trace element composition similar to the high-Mg adakites erupted in the AVZ. We interpret this adakitic glass to be a quenched slab melt that has infiltrated the mantle wedge from below. The texture...
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Journal Article
Journal: Geology
Published: 01 December 2002
Geology (2002) 30 (12): 1111-1114.
... ( Kay, 1978 ) in subduction zones. However, some rocks with adakitic compositional features have been considered to have alternative origins, e.g., assimilation–fractional crystallization (AFC) processes involving a basaltic magma ( Castillo et al., 1999 ), or partial melting of mafic lower crust (e.g...
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Journal Article
Journal: GSA Bulletin
Published: 01 November 2013
GSA Bulletin (2013) 125 (11-12): 1800-1819.
... rocks), these data allow us to infer the composition of their source materials, and corresponding formation mechanisms. The new geochemical data indicate that they have the characteristics of high-Mg# adakitic rocks, which were probably derived from melting of delaminated lower crust. Their distinctive...
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Journal Article
Journal: Geology
Published: 01 November 2002
Geology (2002) 30 (11): 967-970.
... subducted slab is the source of adakitic magmas. Between these two end-member processes, several additional mechanisms can occur ( Prouteau et al., 2001 ; Yogodzinski and Kelemen, 1998 ; Schiano et al., 1995 ): (1) the composition of the slab melt is modified during ascent through the mantle wedge...
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Journal Article
Journal: GSA Bulletin
Published: 01 September 2016
GSA Bulletin (2016) 128 (9-10): 1367-1382.
... ( Huang et al., 2009 ), and their Sr-Nd isotopic compositions ([ 144 Nd/ 143 Nd] i = 0.5117–0.5122, [ 87 Sr/ 86 Sr] i = 0.7055–0.7129) are unlike those of oceanic slab–derived adakites ( Defant and Drummond, 1990 ; Martin, 1999 ). In particular, their ε Nd ( t ) values (–4.8 to +3.2) are significantly...
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Journal Article
Published: 23 February 2016
Canadian Journal of Earth Sciences (2016) 53 (4): 441-456.
... by Caroff et al. (2015) as entirely — or predominantly — crust-derived materials. Lastly, adakitic trondhjemites display isotopic compositions midway between those two. Field relationships indicate that these three syn- (or slightly post-) depositional magmatic groups are overall contemporaneous...
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Journal Article
Published: 02 August 2017
Geological Magazine (2017) 155 (1): 132-148.
... line (Dhuime, Hawkesworth & Cawood, 2011 ) ( Fig. 10 ), implying that the Jiacha adakitic tonalites were probably formed by reworking of Neoproterozoic mafic lower crust ( Figs 9 , 10 ). However, the tonalites from the different bodies have inconsistent Hf isotopic compositions, with some high ε...
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