Anorthite megacrysts from island arc basalts

1995 ◽  
Vol 59 (394) ◽  
pp. 1-14 ◽  
Author(s):  
Mitsuyoshi Kimata ◽  
Norimasa Nishida ◽  
Masahiro Shimizu ◽  
Shizuo Saito ◽  
Tomoaki Matsui ◽  
...  
Keyword(s):  
Planetary Nebula ◽  
Isotope Ratio ◽  
Island Arc ◽  
Japanese Island ◽  
Sr Isotope ◽  
Native Copper ◽  
Chemical Zoning ◽  
Basaltic Magmas ◽  
End Members ◽  
Lateral Variations

AbstractAnorthite megacrysts are common in basalts from the Japanese Island Arc, and signally rare in other global fields. These anorthites are 1 to 3 cm in size and often contain several corroded Mg-olivine inclusions. The megacrysts generally range from An94Ab4Ot2 to An89Ab6Ot5 (Ot: other minor end-members, including CaFeSi3O8, CaMgSi3O8, AlAl3SiO8, □Si4O8) and show no chemical zoning. They often show parting. Redclouded megacrysts contain microcrystals of native copper with a distribution reminiscent of the shape of a planetary nebula. Hydrocarbons are also present, both in the anorthite megacrysts and in the olivines included within them. Implications of lateral variations in the Fe/Mg ratio of the included olivines, in Sr-content and in Sr-isotope ratio of the anorthite megacrysts with respect to the Japanese island arc, relate to mixing of crustal components and subducted slab-sediments into the basaltic magmas.

scholarly journals Petroleum resources in the Japanese island-arc setting

Episodes ◽  
1991 ◽  
Vol 14 (3) ◽  
pp. 236-241 ◽  
Author(s):  
Yoshiro Kikuchi ◽  
Satoshi Tono ◽  
Masaaki Funayama
Keyword(s):  
Island Arc ◽  
Japanese Island ◽  
Petroleum Resources ◽  
Arc Setting

Improved in-situ Determination of Sr Isotope Ratio in Silicate Samples Using LA-MC-ICP-MS and Its Wider Application for Fused Rock Powder

2019 ◽  
Vol 31 (2) ◽  
pp. 262-270 ◽  
Author(s):  
Lüyun Zhu ◽  
Ganglan Zhang ◽  
Yongsheng Liu ◽  
Jie Lin ◽  
Xirun Tong ◽  
...  
Keyword(s):  
Isotope Ratio ◽  
Sr Isotope ◽  
Rock Powder ◽  
Sr Isotope Ratio ◽  
Icp Ms

Nd and Sr isotope geochemistry of island arc volcanics, Grenada, Lesser Antilles

1979 ◽  
Vol 45 (2) ◽  
pp. 237-248 ◽  
Author(s):  
C.J. Hawkesworth ◽  
R.K. O'Nions ◽  
R.J. Arculus
Keyword(s):  
Isotope Geochemistry ◽  
Island Arc ◽  
Lesser Antilles ◽  
Sr Isotope

scholarly journals Resolving Sediment Subduction and Crustal Contamination in the Lesser Antilles Island Arc: a Combined He–O–Sr Isotope Approach

2002 ◽  
Vol 43 (1) ◽  
pp. 143-170 ◽  
Author(s):  
MATTHIJS C. VAN SOEST ◽  
DAVID R. HILTON ◽  
COLIN G. MACPHERSON ◽  
DAVID P. MATTEY
Keyword(s):  
Crustal Contamination ◽  
Island Arc ◽  
Lesser Antilles ◽  
Sr Isotope

scholarly journals Light hydrocarbons in volcanic gases from the Japanese island arc.

1995 ◽  
Vol 29 (4) ◽  
pp. 231-242 ◽  
Author(s):  
Yasuhiro Kiyosu ◽  
Noriko Asada
Keyword(s):  
Island Arc ◽  
Volcanic Gases ◽  
Japanese Island ◽  
Light Hydrocarbons

scholarly journals Determining water sources in the boundary layer from tall tower profiles of water vapor and surface water isotope ratios after a snowstorm in Colorado

2012 ◽  
Vol 12 (7) ◽  
pp. 16327-16375 ◽  
Author(s):  
D. Noone ◽  
C. Risi ◽  
A. Bailey ◽  
M. Berkelhammer ◽  
D. P. Brown ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Surface Water ◽  
Isotope Ratio ◽  
Water Flux ◽  
Vertical Mixing ◽  
Surface Fluxes ◽  
Balance Model ◽  
Snow Pack ◽  
Low Level Jets ◽  
End Members

Abstract. The D/H isotope ratio is used to attribute boundary layer humidity changes to the set of contributing fluxes for a case following a snowstorm in which a snow pack of about 10 cm vanished. Profiles of H2O and CO2 mixing ratio, D/H isotope ratio, and several thermodynamic properties were measured from the surface to 300 m every 15 min during four winter days near Boulder, Colorado. Coeval analysis of the D/H ratios and CO2 concentrations find these two variables to be complementary with the former being sensitive to daytime surface fluxes and the latter particularly indicative of nocturnal surface sources. Together they capture evidence for strong vertical mixing during the day, weaker mixing by turbulent bursts and low level jets within the nocturnal stable boundary layer during the night, and frost formation in the morning. The profiles are generally not well described with a gradient mixing line analysis because D/H ratios of the end members (i.e., surface fluxes and the free troposphere) evolve throughout the day which leads to large uncertainties in the estimate of the D/H ratio of surface water flux. A mass balance model is constructed for the snow pack, and constrained with observations to provide an optimal estimate of the partitioning of the surface water flux into contributions from sublimation, evaporation of melt water in the snow and evaporation from ponds. Results show that while vapor measurements are important in constraining surface fluxes, measurements of the source reservoirs (soil water, snow pack and standing liquid) offer stronger constraint on the surface water balance. Measurements of surface water are therefore essential in developing observational programs that seek to use isotopic data for flux attribution.

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