 | Vallier, T.L., Jenner, G.A., Frey, F.A., Gill, J.B., Davis, A.S., Volpe, A.M., Hawkins, J.W., Morris, J.D., Cawood, P.A., Morton, J.L., Scholl, D.W., Rautenschlein, M., White, W.M., Williams, R.W., Stevenson, A.J., White, L.D. (1991) Subalkaline andesite from Valu Fa Ridge, a back-arc spreading center in southern Lau Basin: petrogenesis, comparative chemistry, and tectonic implications. Chemical Geology, 91 (3) 227-256 doi:10.1016/0009-2541(91)90002-9 | Journal (article/letter/editorial) | | most lavas from the TVA, except samples from Ata Island, and are similar to many Lau Basin lavas; (2)...is not unique. Collision of the Louisville and Tonga ridges probably activated back-arc extension that...major morphologic and tectonic features of the Tonga-Lau region (modified from Chase, 19 8 5 ). Approximate...with the Tonga Ridge forearc. 2. Geological setting of the Valu Fa Ridge An ancient Tonga-Kermadec island...island arc system was part of the extensive Melanesian arc that rimmed the east coast of Australia (Kroenke |  | | Journal (article/letter/editorial) | | The Pleistocene-Recent Tonga-Kermadec Arc Lavas: Interpretation of New Isotopic and Rare Earth Data in...range from extremely HFS element depleted (northern Tonga) to near N-MORB-like HFS element abundances in L'Esperance...account for differences in chemistry between the Tonga and Kermadec arc segments. The mechanism of LILE...zone, involving induced convection. The back-arc island of Niua fo'ou is geochemically quite distinct from...Pleistocene-Recent volcanoes erupted along the linear Kermadec-Tonga arc (Fig. 1) constitute a clear example of intra-oceanic |  | | Journal (article/letter/editorial) | | diagenetic alteration of volcanoclastic sediments in the Tonga fore-arc: Evidence from chemical and strontium isotopic...components dissolved in interstitial waters from the Tonga margin (ODP Site 841 ) are much more pronounced...years). The extensive diagenetic processes in the Tonga margin were mostly caused by the recent intrusion...composition of the interstitial waters from the Tonga margin. The specific questions to be answered here...located at 23020,7 ' S and 175°17,9'W on the upper Tonga Trench slope at a water depth of 4810 m (Fig. 1) |  | | Journal (article/letter/editorial) | | northeastern part of the Lau Basin east of Niuafo'ou Island at approximately 15°S. The lavas from the KTJ can...northeastern part of the basin east of Niuafo'ou Island, 2) the Central Lau Spreading Center (CLSC) which...mark the axis of the most recent volcanism in the Tonga arc and define the current position of the volcanic...kilometres (Isacks and Barazangi, 1977). Lau Ridge and Tonga Ridge are defined by the 2000 m bathymetric contour...Lau back-arc basin basalts overlap those of ocean island basalts (OIB) such as the Samoan alkaline volcanics |  | PEATE, DAVID W., KOKFELT, THOMAS F., HAWKESWORTH, CHRIS J., VAN CALSTEREN, PETER W., HERGT, JANET M., PEARCE, JULIAN A. (2001) U-series Isotope Data on Lau Basin Glasses: the Role of Subduction-related Fluids during Melt Generation in Back-arc Basins. Journal of Petrology, 42 (8) 1449-1470 doi:10.1093/petrology/42.8.1449 | Journal (article/letter/editorial) | | with existing 230 Th–238U data for the Central Tonga arc to infer a fluid addition event at >50 ka. The...PETROLOGY VOLUME 42 Fig. 1. Tectonic map of the Tonga–Lau arc–back-arc system, after Hergt & Hawkesworth...Kermadec arc is the lateral continuation of the Tonga arc, south of 23°S. Χ, location of drill sites from...control 238U–230Th disequilibria in magmas from island-arc environments appear to be different from those...1998b; Bourdon et al., 1996b; Elliott, 1997). For island-arc magmas, 238U–230Th disequilibria are more common |  | | Journal (article/letter/editorial) | | (226Ra/230Th) with Sr/Th and Ba/Th observed in the Tonga arc could reflect AFC process. Results of our model... Specifically, fractional crystallization of plagioclase and amphibole coupled with contemporaneous decay...fractionated mineral phases include Na-rich plagioclase and amphibole, DRa will be significantly greater...continental subduction zones, mid-ocean ridges or ocean island settings. 4.1. Choice of partition coefficients As...choice of crystal-melt partition coefficients for plagioclase and amphibole, the most important mineral phases |  | Turner, Simon, Hawkesworth, Chris, Rogers, Nick, Bartlett, Jessica, Worthington, Tim, Hergt, Janet, Pearce, Julian, Smith, Ian (1997) 238U230Th disequilibria, magma petrogenesis, and flux rates beneath the depleted Tonga-Kermadec island arc. Geochimica et Cosmochimica Acta, 61 (22) 4855-4884 doi:10.1016/s0016-7037(97)00281-0 | Journal (article/letter/editorial) | | petrogenesis, and flux rates beneath the depleted Tonga-Kermadec island arc SIMON TURNER,1.. CHRIS HAWKESWORTH,1...- - T h e highly depleted intra-oceanic Tonga-Kermadec island arc forms an endmember of arc systems and...sediments at DSDP site 204 just to the east of the Tonga-Kermadec trench. Ca/Ti and AI/Ti ratios extend from...in the southern Kermadecs to very high ratios in Tonga interpreted to reflect increasing degrees of depletion...signature is not observed in lavas from the backarc island of Niuafo'ou. These were derived from partial melting |  | Kamenetsky, Vadim S., Crawford, Anthony J., Eggins, Stephen, Mühe, Richard (1997) Phenocryst and melt inclusion chemistry of near-axis seamounts, Valu Fa Ridge, Lau Basin: insight into mantle wedge melting and the addition of subduction components. Earth and Planetary Science Letters, 151 (3) 205-223 doi:10.1016/s0012-821x(97)81849-3 | Journal (article/letter/editorial) | | Spreading Center magmas, Keyvords: Lau Basin: island arcs; magmas: _ 2-3 were produced Ma. 0 1997...from normal mid-ocean ridge basalts (NMORB) toward island arc tholeiites (IAT) is believed to reflect progressive...Fa Ridge. is only 40 km west of the arc volcano, Ata, and is spreading at 90- 130 mm/yr [6]. The samples...this study). Fig. 1. Map of Lau Basin and Tonga Trench-Tonga Ridge system and Lau Ridge showing the areas...whereas El and WI are olivine + clinopyroxene + plagioclase-phyric. In all three samples olivine is the dominant |  | | Journal (article/letter/editorial) | | with high LILE and HFSE, characteristic of ocean island basalts. LVG lavas have high end ( + 8 . 0 - -...70375). LVG lavas were erupted in a primary oceanic island arc (Vitiaz arc) during the Miocene. Basaltic lavas...Andesites and dacites were produced by low-pressure plagioclase-pyroxene-titanomagnetite dominated crystal fractionation...unreOffprint requests: J.W. Cole lated to the present-day Tonga arc, and the lack of depletion indicators suggests...introduction of sub-Pacific mantle through the present Tonga-Lau subduction system. Introduction The islands |  | | Journal (article/letter/editorial) | | strength and transition element systematics in island arc and back-arc basin basalts" evidence for multi-phase...elements Ti, Zr, V, Sc and Y in basaltic rocks from island arcs and associated back-arc basins. Systematic...to that of the high field strength elements in island arc basalts. The observations are not compatible...enriched mantle sources similar to those of ocean island basalts (OIB) [e.g., 5,6]. A complementary approach...the slab [7]. The behaviour of these elements in island arc basalts (IAB) will be determined solely by |  | | Report (issue) | | behind the Tonga island arc. It is an elongate, south-verging interarc basin between the Tonga-Kermadec...andesite and minor basaltic andesite and one sample of island arc basaltic andesite. Northern Study Area Nine...location slightly east of Valu Fa Ridge, resembles an island arc basaltic andesite (87KD). All of the samples...been involved The K^O/Pf); ratio (Fig. 9a) of the island arc basaltic andesite (~8) differs significantly...from an island arc magma. A parental magma intermediate in composition between MORB and an island arc basalt |  | | Report (chapter) | | lithosohere I n,ell FOR MANTLE 375 MELTING B: Island arc: tAT source + thin lithosohere partial melting...breakdown releases water C: Island arc: tAT source + thick lithosoher~ D: Island arc: alreadv-deoleted source...::r'l I Tongoa, Vanuatu I r 10 I Island arctholeiite; Ata, Tonga I I I I 1) 0 1 .1 , , , ,...melting relative to MORB. The second pattern, from Ata in the Tofua arc (Vallier et al. 1985), shows a progressive...enrichments to enriched mantle in the wedge (an 'ocean island basalt (OIB)' component) (e.g. Stern et al. 1991) |  | Ewart, A., Collerson, K. D., Regelous, M., Wendt, J. I., Niu, Y. (1998) Geochemical Evolution within the Tonga-Kermadec-Lau Arc-Back-arc Systems: the Role of Varying Mantle Wedge Composition in Space and Time. Journal of Petrology, 39 (3) 331-368 doi:10.1093/petroj/39.3.331 | Journal (article/letter/editorial) | | 331–368 1998 Geochemical Evolution within the Tonga–Kermadec–Lau Arc–Back-arc Systems: the Role of Varying... and Pb isotope data for lavas from the active Tonga–Kermadec arc in the southwest Pacific, the volcano...arc–back-arc system. Geochemical variations in Tonga–Kermadec arc lavas are the result of (1) differences...subducted beneath the arc, compared with ~200 m at the Tonga Trench. This results in the high Th/U and more radiogenic...isotope compositions of Kermadec lavas compared with Tonga lavas. The latter have Pb isotope compositions intermediate |  | | Report (issue) | | Sediments andtheGeodynamic Evolution of Western Pacific Island Arcs Herv• Cambray,ManuelPubellier,LaurentJolivet...ntleReservoirs Beneaththe CentralNew Hebrides Island Arc AnthonyJ. Crawford,L. Briqueu,C. Laporte,and...community. The spatial and temporal evolution of island arcs is discussedby Arculus et al., Clift, and...Crawford et Intense land and marine studies of the island arcs The middle Eocene initiation a consistent...governmentsof 19 nations. All but one western Pacific island nation generouslygrantedpermissionto drill in their |  | | Report (issue) | | Structural Blue Mountains Region (Or. and Wash.) 2. Island arcs Blue Mountains Region (Or. and Wash.) 3. Rocks...emphasize the region's importance for understanding island-arc processes and the accretion of an allochthonous...papers provide current interpretations of a complex island-arc terrane that was accreted to ancient North...stripped off the older rocks by erosion. Modern island arcs are not well understood, and even less so...narrow fault-bounded terraces. Moreover, some arcs (Tonga-Kermadec) have erupted primarily tholeiitic igneous |  | | Report (chapter) | | lavas in light of modern geodynamic contexts in the Tonga and Fiji regions lead us to define three tectonic...the most refractory sources, compared with normal island arc suites. These primitive arc rocks have distinctive...Boninites are characterized by the absence of plagioclase phenocrysts, and by the presence of very magnesian...boninites could originate from a refractory ocean island basalt (OIB) mantle source (Sharaskin et al. 1983a...including modern forearc regions of intraoceanic island arcs (Falloon & Crawford 1991; Pearce et al. 1992) |  | Rogers, R., Ross, P.-S., Goutier, J., Mercier-Langevin, P. (2014) Using Physical Volcanology, Chemical Stratigraphy, and Pyrite Geochemistry for Volcanogenic Massive Sulfide Exploration: An Example from the Blake River Group, Abitibi Greenstone Belt,. Economic Geology, 109 (1) 61-88 doi:10.2113/econgeo.109.1.61 | Journal (article/letter/editorial) | | andesites plot in the MORB field but not far from the island-arc basalt (IAB) field (Fig. 7G). Finally, in the...ridge basalt, E-MORB = enriched MORB; OIB = ocean island basalt; (F) from arc environments: BABB = back-arc...IAT = island-arc tholeiite (avg of samples 482-8-1, 482-8-8, 482-8-11, and 482-8-12 from Ata island, Tonga...calc-alkaline basalt (avg of samples 67150 and 67154, island of Flores, Sunda arc, after Stolz et al., 1990)...discrimination diagram from Agrawal et al. (2008). IAB = island-arc basalt; CRB = continental rift basalt. Discriminant |
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