Petrology and geochemistry of the central North Fiji Basin spreading centre (Southwest Pacific) between 16°S and 22°S
Identifieur interne : 001C41 ( Istex/Corpus ); précédent : 001C40; suivant : 001C42Petrology and geochemistry of the central North Fiji Basin spreading centre (Southwest Pacific) between 16°S and 22°S
Auteurs : Jean-Philippe Eissen ; Christian Lefe Vre ; Patrick Maillet ; Gilles Morvan ; Masato NoharaSource :
- Marine Geology [ 0025-3227 ] ; 1991.
Abstract
Abstract: The North Fiji Basin (NFB) is a 12 m.y. old back-arc basin that has a complex multi-stage history. The presently active spreading system can be divided into four segments between 16°S and 22°S, which from north to south trend N160, N15 and N-S (the fourth segment is the N-S trending segment located near 174E). The main N-S segment is morphologically similar to other medium-rate oceanic ridges, whereas the other segments have rougher morphologies which have been severely disturbed by a triple junction at 16°45S and several instability features such as overlapping spreading centres (OSCs) and propagating rifts. The spreading rate seems to diminish from 7.8 cm/yr near 20°S to 4.6 cm/yr near 18°S. Mineralogical, pertological and geochemical data were obtained on 24 new stations located along all the four segments. The petrogenesis of the basalts collected is essentially controlled by low-pressure crystal fractionation of plagioclase±olivine±clinopyroxene (plagioclase>olivine>clinopyroxene) with 52% of the NFB basalts reaching the four-phase cotectic. Locally, some magma mixing occurs, but this is limited to magma batches of closely related composition, as might be expected to occur inside a magma reservoir. The N-S segment, which, since 3 m.y., is the only steady-state segment, is also petrologically and geochemically very comparable to other medium-rate oceanic spreading centres, producing moderately evolved LILE and LREE-depleted N-MORB. In contrast, the three other segments produce basalts of much more variable petrology and geochemistry characterized by LILE and slightly LREE-enriched magmas cf back-arc basin basalt (BABB) affinity (but not as enriched as, for example, the Mariana BABB); MORB is, however, also found on the N160, N15 and 174E segments. Diagrams using Ba, Rb, K/P and (K/Ti)N (Normalized to the chondrites) plotted against latitude clearly show along-strike variations. Beneath the recently formed segments, the mantle source is heterogeneous, and locally has some BABB affinities, whereas beneath the more steady-state N-S segment the magma source is more homogeneous, being generally depleted in LILE and REE as is the case for classical N-MORB mantle sources. Simple evolution from an early stage of BABB production to MORB described in the Lau basin and proposed for the NFB does not seem to occur. Present-day activity still produces large amounts of BABB along the less-stable and more recently created segments, and MORB was produced in the earlier stages of the development of the NFB.
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DOI: 10.1016/0025-3227(91)90104-C
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sortKey="Maillet, Patrick" sort="Maillet, Patrick" uniqKey="Maillet P" first="Patrick" last="Maillet">Patrick Maillet</name><affiliation><mods:affiliation>ORSTOM, La Trobe University, Geology Department, Bundoora, Vic. 3083, Australia</mods:affiliation></affiliation></author><author><name sortKey="Morvan, Gilles" sort="Morvan, Gilles" uniqKey="Morvan G" first="Gilles" last="Morvan">Gilles Morvan</name><affiliation><mods:affiliation>Universite´de Bretagne Occidentale, Faculte´des Sciences, 6 Avenue Le Gorgeu, 29263 Brest Cedex, France</mods:affiliation></affiliation></author><author><name sortKey="Nohara, Masato" sort="Nohara, Masato" uniqKey="Nohara M" first="Masato" last="Nohara">Masato Nohara</name><affiliation><mods:affiliation>Geological Survey of Japan, Tsukuba, Ibaraki 305, Japan</mods:affiliation></affiliation></author></titleStmt><publicationStmt><idno type="wicri:source">ISTEX</idno><idno type="RBID">ISTEX:596AC6B24BD49C89EFBA1A98ECB368EA4854894F</idno><date when="1991" 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Vre">Christian Lefe Vre</name><affiliation><mods:affiliation>Universite´des Sciences et Techniques de Lille, Sciences de la Terre, 59655 Villeneuve d'Ascq Cedex, France</mods:affiliation></affiliation></author><author><name sortKey="Maillet, Patrick" sort="Maillet, Patrick" uniqKey="Maillet P" first="Patrick" last="Maillet">Patrick Maillet</name><affiliation><mods:affiliation>ORSTOM, La Trobe University, Geology Department, Bundoora, Vic. 3083, Australia</mods:affiliation></affiliation></author><author><name sortKey="Morvan, Gilles" sort="Morvan, Gilles" uniqKey="Morvan G" first="Gilles" last="Morvan">Gilles Morvan</name><affiliation><mods:affiliation>Universite´de Bretagne Occidentale, Faculte´des Sciences, 6 Avenue Le Gorgeu, 29263 Brest Cedex, France</mods:affiliation></affiliation></author><author><name sortKey="Nohara, Masato" sort="Nohara, Masato" uniqKey="Nohara M" first="Masato" last="Nohara">Masato Nohara</name><affiliation><mods:affiliation>Geological Survey of Japan, Tsukuba, Ibaraki 305, Japan</mods:affiliation></affiliation></author></analytic><monogr></monogr><series><title level="j">Marine Geology</title><title level="j" type="abbrev">MARGO</title><idno type="ISSN">0025-3227</idno><imprint><publisher>ELSEVIER</publisher><date type="published" when="1991">1991</date><biblScope unit="volume">98</biblScope><biblScope unit="issue">2–4</biblScope><biblScope unit="page" from="201">201</biblScope><biblScope unit="page" to="239">239</biblScope></imprint><idno type="ISSN">0025-3227</idno></series><idno type="istex">596AC6B24BD49C89EFBA1A98ECB368EA4854894F</idno><idno type="DOI">10.1016/0025-3227(91)90104-C</idno><idno type="PII">0025-3227(91)90104-C</idno><idno type="ArticleID">9190104C</idno></biblStruct></sourceDesc><seriesStmt><idno type="ISSN">0025-3227</idno></seriesStmt></fileDesc><profileDesc><textClass></textClass><langUsage><language ident="en">en</language></langUsage></profileDesc></teiHeader><front><div type="abstract" xml:lang="en">Abstract: The North Fiji Basin (NFB) is a 12 m.y. old back-arc basin that has a complex multi-stage history. The presently active spreading system can be divided into four segments between 16°S and 22°S, which from north to south trend N160, N15 and N-S (the fourth segment is the N-S trending segment located near 174E). The main N-S segment is morphologically similar to other medium-rate oceanic ridges, whereas the other segments have rougher morphologies which have been severely disturbed by a triple junction at 16°45S and several instability features such as overlapping spreading centres (OSCs) and propagating rifts. The spreading rate seems to diminish from 7.8 cm/yr near 20°S to 4.6 cm/yr near 18°S. Mineralogical, pertological and geochemical data were obtained on 24 new stations located along all the four segments. The petrogenesis of the basalts collected is essentially controlled by low-pressure crystal fractionation of plagioclase±olivine±clinopyroxene (plagioclase>olivine>clinopyroxene) with 52% of the NFB basalts reaching the four-phase cotectic. Locally, some magma mixing occurs, but this is limited to magma batches of closely related composition, as might be expected to occur inside a magma reservoir. The N-S segment, which, since 3 m.y., is the only steady-state segment, is also petrologically and geochemically very comparable to other medium-rate oceanic spreading centres, producing moderately evolved LILE and LREE-depleted N-MORB. In contrast, the three other segments produce basalts of much more variable petrology and geochemistry characterized by LILE and slightly LREE-enriched magmas cf back-arc basin basalt (BABB) affinity (but not as enriched as, for example, the Mariana BABB); MORB is, however, also found on the N160, N15 and 174E segments. Diagrams using Ba, Rb, K/P and (K/Ti)N (Normalized to the chondrites) plotted against latitude clearly show along-strike variations. Beneath the recently formed segments, the mantle source is heterogeneous, and locally has some BABB affinities, whereas beneath the more steady-state N-S segment the magma source is more homogeneous, being generally depleted in LILE and REE as is the case for classical N-MORB mantle sources. Simple evolution from an early stage of BABB production to MORB described in the Lau basin and proposed for the NFB does not seem to occur. Present-day activity still produces large amounts of BABB along the less-stable and more recently created segments, and MORB was produced in the earlier stages of the development of the NFB.</div></front></TEI><istex><corpusName>elsevier</corpusName><author><json:item><name>Jean-Philippe Eissen</name><affiliations><json:string>Centre ORSTOM, BP A5, Noume´a Cedex, New Caledonia</json:string><json:string>1Member of GDR 910, “Genese et Evolution des Domaines Oce´aniques, Brest</json:string></affiliations></json:item><json:item><name>Christian Lefe`vre</name><affiliations><json:string>Universite´des Sciences et Techniques de Lille, Sciences de la Terre, 59655 Villeneuve d'Ascq Cedex, France</json:string></affiliations></json:item><json:item><name>Patrick Maillet</name><affiliations><json:string>ORSTOM, La Trobe University, Geology Department, Bundoora, Vic. 3083, Australia</json:string></affiliations></json:item><json:item><name>Gilles Morvan</name><affiliations><json:string>Universite´de Bretagne Occidentale, Faculte´des Sciences, 6 Avenue Le Gorgeu, 29263 Brest Cedex, France</json:string></affiliations></json:item><json:item><name>Masato Nohara</name><affiliations><json:string>Geological Survey of Japan, Tsukuba, Ibaraki 305, Japan</json:string></affiliations></json:item></author><articleId><json:string>9190104C</json:string></articleId><language><json:string>eng</json:string></language><originalGenre><json:string>Full-length article</json:string></originalGenre><abstract>The North Fiji Basin (NFB) is a 12 m.y. old back-arc basin that has a complex multi-stage history. The presently active spreading system can be divided into four segments between 16°S and 22°S, which from north to south trend N160, N15 and N-S (the fourth segment is the N-S trending segment located near 174E). The main N-S segment is morphologically similar to other medium-rate oceanic ridges, whereas the other segments have rougher morphologies which have been severely disturbed by a triple junction at 16°45S and several instability features such as overlapping spreading centres (OSCs) and propagating rifts. The spreading rate seems to diminish from 7.8 cm/yr near 20°S to 4.6 cm/yr near 18°S. Mineralogical, pertological and geochemical data were obtained on 24 new stations located along all the four segments. The petrogenesis of the basalts collected is essentially controlled by low-pressure crystal fractionation of plagioclase±olivine±clinopyroxene (plagioclase>olivine>clinopyroxene) with 52% of the NFB basalts reaching the four-phase cotectic. Locally, some magma mixing occurs, but this is limited to magma batches of closely related composition, as might be expected to occur inside a magma reservoir. The N-S segment, which, since 3 m.y., is the only steady-state segment, is also petrologically and geochemically very comparable to other medium-rate oceanic spreading centres, producing moderately evolved LILE and LREE-depleted N-MORB. In contrast, the three other segments produce basalts of much more variable petrology and geochemistry characterized by LILE and slightly LREE-enriched magmas cf back-arc basin basalt (BABB) affinity (but not as enriched as, for example, the Mariana BABB); MORB is, however, also found on the N160, N15 and 174E segments. Diagrams using Ba, Rb, K/P and (K/Ti)N (Normalized to the chondrites) plotted against latitude clearly show along-strike variations. Beneath the recently formed segments, the mantle source is heterogeneous, and locally has some BABB affinities, whereas beneath the more steady-state N-S segment the magma source is more homogeneous, being generally depleted in LILE and REE as is the case for classical N-MORB mantle sources. Simple evolution from an early stage of BABB production to MORB described in the Lau basin and proposed for the NFB does not seem to occur. Present-day activity still produces large amounts of BABB along the less-stable and more recently created segments, and MORB was produced in the earlier stages of the development of the NFB.</abstract><qualityIndicators><score>8.5</score><pdfVersion>1.4</pdfVersion><pdfPageSize>540 x 742 pts</pdfPageSize><refBibsNative>true</refBibsNative><keywordCount>0</keywordCount><abstractCharCount>2538</abstractCharCount><pdfWordCount>14421</pdfWordCount><pdfCharCount>104953</pdfCharCount><pdfPageCount>39</pdfPageCount><abstractWordCount>383</abstractWordCount></qualityIndicators><title>Petrology and geochemistry of the central North Fiji Basin spreading centre (Southwest Pacific) between 16°S and 22°S</title><pii><json:string>0025-3227(91)90104-C</json:string></pii><genre><json:string>research-article</json:string></genre><serie><pages><first>371</first></pages><language><json:string>unknown</json:string></language><title>Sche´ma d'e´volution morphologique de l'axe de dorsales: liaison avec l'hydrothermalisme</title></serie><host><volume>98</volume><pii><json:string>S0025-3227(00)X0243-5</json:string></pii><pages><last>239</last><first>201</first></pages><issn><json:string>0025-3227</json:string></issn><issue>2–4</issue><genre><json:string>journal</json:string></genre><language><json:string>unknown</json:string></language><title>Marine Geology</title><publicationDate>1991</publicationDate></host><categories><wos><json:string>GEOSCIENCES, MULTIDISCIPLINARY</json:string><json:string>OCEANOGRAPHY</json:string></wos></categories><publicationDate>1991</publicationDate><copyrightDate>1991</copyrightDate><doi><json:string>10.1016/0025-3227(91)90104-C</json:string></doi><id>596AC6B24BD49C89EFBA1A98ECB368EA4854894F</id><score>0.06860781</score><fulltext><json:item><original>true</original><mimetype>application/pdf</mimetype><extension>pdf</extension><uri>https://api.istex.fr/document/596AC6B24BD49C89EFBA1A98ECB368EA4854894F/fulltext/pdf</uri></json:item><json:item><original>false</original><mimetype>application/zip</mimetype><extension>zip</extension><uri>https://api.istex.fr/document/596AC6B24BD49C89EFBA1A98ECB368EA4854894F/fulltext/zip</uri></json:item><istex:fulltextTEI uri="https://api.istex.fr/document/596AC6B24BD49C89EFBA1A98ECB368EA4854894F/fulltext/tei"><teiHeader><fileDesc><titleStmt><title level="a" type="main" xml:lang="en">Petrology and geochemistry of the central North Fiji Basin spreading centre (Southwest Pacific) between 16°S and 22°S</title></titleStmt><publicationStmt><authority>ISTEX</authority><publisher>ELSEVIER</publisher><availability><p>©1991 Elsevier Science Publishers B.V. All rights reserved</p></availability><date>1991</date></publicationStmt><sourceDesc><biblStruct type="inbook"><analytic><title level="a" type="main" xml:lang="en">Petrology and geochemistry of the central North Fiji Basin spreading centre (Southwest Pacific) between 16°S and 22°S</title><author xml:id="author-1"><persName><forename type="first">Jean-Philippe</forename><surname>Eissen</surname></persName><affiliation>Centre ORSTOM, BP A5, Noume´a Cedex, New Caledonia</affiliation><affiliation>1Member of GDR 910, “Genese et Evolution des Domaines Oce´aniques, Brest</affiliation></author><author xml:id="author-2"><persName><forename type="first">Christian</forename><surname>Lefe`vre</surname></persName><affiliation>Universite´des Sciences et Techniques de Lille, Sciences de la Terre, 59655 Villeneuve d'Ascq Cedex, France</affiliation></author><author xml:id="author-3"><persName><forename type="first">Patrick</forename><surname>Maillet</surname></persName><affiliation>ORSTOM, La Trobe University, Geology Department, Bundoora, Vic. 3083, Australia</affiliation></author><author xml:id="author-4"><persName><forename type="first">Gilles</forename><surname>Morvan</surname></persName><affiliation>Universite´de Bretagne Occidentale, Faculte´des Sciences, 6 Avenue Le Gorgeu, 29263 Brest Cedex, France</affiliation></author><author xml:id="author-5"><persName><forename type="first">Masato</forename><surname>Nohara</surname></persName><affiliation>Geological Survey of Japan, Tsukuba, Ibaraki 305, Japan</affiliation></author></analytic><monogr><title level="j">Marine Geology</title><title level="j" type="abbrev">MARGO</title><idno type="pISSN">0025-3227</idno><idno type="PII">S0025-3227(00)X0243-5</idno><imprint><publisher>ELSEVIER</publisher><date type="published" when="1991"></date><biblScope unit="volume">98</biblScope><biblScope unit="issue">2–4</biblScope><biblScope unit="page" from="201">201</biblScope><biblScope unit="page" to="239">239</biblScope></imprint></monogr><idno type="istex">596AC6B24BD49C89EFBA1A98ECB368EA4854894F</idno><idno type="DOI">10.1016/0025-3227(91)90104-C</idno><idno type="PII">0025-3227(91)90104-C</idno><idno type="ArticleID">9190104C</idno></biblStruct></sourceDesc></fileDesc><profileDesc><creation><date>1991</date></creation><langUsage><language ident="en">en</language></langUsage><abstract xml:lang="en"><p>Abstract: The North Fiji Basin (NFB) is a 12 m.y. old back-arc basin that has a complex multi-stage history. The presently active spreading system can be divided into four segments between 16°S and 22°S, which from north to south trend N160, N15 and N-S (the fourth segment is the N-S trending segment located near 174E). The main N-S segment is morphologically similar to other medium-rate oceanic ridges, whereas the other segments have rougher morphologies which have been severely disturbed by a triple junction at 16°45S and several instability features such as overlapping spreading centres (OSCs) and propagating rifts. The spreading rate seems to diminish from 7.8 cm/yr near 20°S to 4.6 cm/yr near 18°S. Mineralogical, pertological and geochemical data were obtained on 24 new stations located along all the four segments. The petrogenesis of the basalts collected is essentially controlled by low-pressure crystal fractionation of plagioclase±olivine±clinopyroxene (plagioclase>olivine>clinopyroxene) with 52% of the NFB basalts reaching the four-phase cotectic. Locally, some magma mixing occurs, but this is limited to magma batches of closely related composition, as might be expected to occur inside a magma reservoir. The N-S segment, which, since 3 m.y., is the only steady-state segment, is also petrologically and geochemically very comparable to other medium-rate oceanic spreading centres, producing moderately evolved LILE and LREE-depleted N-MORB. In contrast, the three other segments produce basalts of much more variable petrology and geochemistry characterized by LILE and slightly LREE-enriched magmas cf back-arc basin basalt (BABB) affinity (but not as enriched as, for example, the Mariana BABB); MORB is, however, also found on the N160, N15 and 174E segments. Diagrams using Ba, Rb, K/P and (K/Ti)N (Normalized to the chondrites) plotted against latitude clearly show along-strike variations. Beneath the recently formed segments, the mantle source is heterogeneous, and locally has some BABB affinities, whereas beneath the more steady-state N-S segment the magma source is more homogeneous, being generally depleted in LILE and REE as is the case for classical N-MORB mantle sources. Simple evolution from an early stage of BABB production to MORB described in the Lau basin and proposed for the NFB does not seem to occur. Present-day activity still produces large amounts of BABB along the less-stable and more recently created segments, and MORB was produced in the earlier stages of the development of the NFB.</p></abstract></profileDesc><revisionDesc><change when="1991">Published</change></revisionDesc></teiHeader></istex:fulltextTEI><json:item><original>false</original><mimetype>text/plain</mimetype><extension>txt</extension><uri>https://api.istex.fr/document/596AC6B24BD49C89EFBA1A98ECB368EA4854894F/fulltext/txt</uri></json:item></fulltext><metadata><istex:metadataXml wicri:clean="Elsevier doc found" wicri:toSee="Elsevier, no converted or simple article"><istex:xmlDeclaration>version="1.0" encoding="utf-8"</istex:xmlDeclaration><istex:docType PUBLIC="-//ES//DTD journal article DTD version 5.0.1//EN//XML" URI="art501.dtd" name="istex:docType"></istex:docType><istex:document><article version="5.0" xml:lang="en" docsubtype="fla"><item-info><jid>MARGO</jid><aid>9190104C</aid><ce:pii>0025-3227(91)90104-C</ce:pii><ce:doi>10.1016/0025-3227(91)90104-C</ce:doi><ce:copyright type="unknown" year="1991">Elsevier Science Publishers B.V. All rights reserved</ce:copyright></item-info><head><ce:title>Petrology and geochemistry of the central North Fiji Basin spreading centre (Southwest Pacific) between 16°S and 22°S</ce:title><ce:author-group><ce:author><ce:given-name>Jean-Philippe</ce:given-name><ce:surname>Eissen</ce:surname><ce:cross-ref refid="aff1"><ce:sup>a</ce:sup></ce:cross-ref><ce:cross-ref refid="fn1"><ce:sup>1</ce:sup></ce:cross-ref></ce:author><ce:author><ce:given-name>Christian</ce:given-name><ce:surname>Lefe`vre</ce:surname><ce:cross-ref refid="aff2"><ce:sup>b</ce:sup></ce:cross-ref></ce:author><ce:author><ce:given-name>Patrick</ce:given-name><ce:surname>Maillet</ce:surname><ce:cross-ref refid="aff3"><ce:sup>c</ce:sup></ce:cross-ref></ce:author><ce:author><ce:given-name>Gilles</ce:given-name><ce:surname>Morvan</ce:surname><ce:cross-ref refid="aff4"><ce:sup>d</ce:sup></ce:cross-ref></ce:author><ce:author><ce:given-name>Masato</ce:given-name><ce:surname>Nohara</ce:surname><ce:cross-ref refid="aff5"><ce:sup>e</ce:sup></ce:cross-ref></ce:author><ce:affiliation id="aff1"><ce:label>a</ce:label><ce:textfn>Centre ORSTOM, BP A5, Noume´a Cedex, New Caledonia</ce:textfn></ce:affiliation><ce:affiliation id="aff2"><ce:label>b</ce:label><ce:textfn>Universite´des Sciences et Techniques de Lille, Sciences de la Terre, 59655 Villeneuve d'Ascq Cedex, France</ce:textfn></ce:affiliation><ce:affiliation id="aff3"><ce:label>c</ce:label><ce:textfn>ORSTOM, La Trobe University, Geology Department, Bundoora, Vic. 3083, Australia</ce:textfn></ce:affiliation><ce:affiliation id="aff4"><ce:label>d</ce:label><ce:textfn>Universite´de Bretagne Occidentale, Faculte´des Sciences, 6 Avenue Le Gorgeu, 29263 Brest Cedex, France</ce:textfn></ce:affiliation><ce:affiliation id="aff5"><ce:label>e</ce:label><ce:textfn>Geological Survey of Japan, Tsukuba, Ibaraki 305, Japan</ce:textfn></ce:affiliation><ce:footnote id="fn1"><ce:label>1</ce:label><ce:note-para>Member of GDR 910, “Gene`se et Evolution des Domaines Oce´aniques”, Brest</ce:note-para></ce:footnote></ce:author-group><ce:date-received day="5" month="3" year="1990"></ce:date-received><ce:date-accepted day="17" month="9" year="1990"></ce:date-accepted><ce:abstract id="ab1" class="author" xml:lang="en"><ce:section-title>Abstract</ce:section-title><ce:abstract-sec><ce:simple-para>The North Fiji Basin (NFB) is a 12 m.y. old back-arc basin that has a complex multi-stage history. The presently active spreading system can be divided into four segments between 16°S and 22°S, which from north to south trend N160, N15 and N-S (the fourth segment is the N-S trending segment located near 174E). The main N-S segment is morphologically similar to other medium-rate oceanic ridges, whereas the other segments have rougher morphologies which have been severely disturbed by a triple junction at 16°45′S and several instability features such as overlapping spreading centres (OSCs) and propagating rifts. The spreading rate seems to diminish from 7.8 cm/yr near 20°S to 4.6 cm/yr near 18°S. Mineralogical, pertological and geochemical data were obtained on 24 new stations located along all the four segments. The petrogenesis of the basalts collected is essentially controlled by low-pressure crystal fractionation of plagioclase±olivine±clinopyroxene (plagioclase>olivine>clinopyroxene) with 52% of the NFB basalts reaching the four-phase cotectic. Locally, some magma mixing occurs, but this is limited to magma batches of closely related composition, as might be expected to occur inside a magma reservoir. The N-S segment, which, since 3 m.y., is the only steady-state segment, is also petrologically and geochemically very comparable to other medium-rate oceanic spreading centres, producing moderately evolved LILE and LREE-depleted N-MORB. In contrast, the three other segments produce basalts of much more variable petrology and geochemistry characterized by LILE and slightly LREE-enriched magmas cf back-arc basin basalt (BABB) affinity (but not as enriched as, for example, the Mariana BABB); MORB is, however, also found on the N160, N15 and 174E segments. Diagrams using Ba, Rb, K/P and (K/Ti)<ce:inf>N</ce:inf> (Normalized to the chondrites) plotted against latitude clearly show along-strike variations. Beneath the recently formed segments, the mantle source is heterogeneous, and locally has some BABB affinities, whereas beneath the more steady-state N-S segment the magma source is more homogeneous, being generally depleted in LILE and REE as is the case for classical N-MORB mantle sources. Simple evolution from an early stage of BABB production to MORB described in the Lau basin and proposed for the NFB does not seem to occur. Present-day activity still produces large amounts of BABB along the less-stable and more recently created segments, and MORB was produced in the earlier stages of the development of the NFB.</ce:simple-para></ce:abstract-sec></ce:abstract></head><tail><ce:bibliography><ce:section-title>References</ce:section-title><ce:bibliography-sec><ce:bib-reference id="bib1"><ce:label>Aggrey et al., 1988</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Aggrey</ce:surname><ce:given-name>K.E.</ce:given-name></sb:author><sb:author><ce:surname>Muenow</ce:surname><ce:given-name>D.W.</ce:given-name></sb:author><sb:author><ce:surname>Sinton</ce:surname><ce:given-name>J.M.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Volatile abundances in submarine glasses from the North Fiji and Lau back-arc basins</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Geochim. Cosmochim. Acta</sb:maintitle></sb:title><sb:volume-nr>52</sb:volume-nr></sb:series><sb:date>1988</sb:date></sb:issue><sb:pages><sb:first-page>2501</sb:first-page><sb:last-page>2506</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib2"><ce:label>Auzende et al., 1986</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Auzende</ce:surname><ce:given-name>J.M.</ce:given-name></sb:author><sb:author><ce:surname>Eissen</ce:surname><ce:given-name>J.P.</ce:given-name></sb:author><sb:author><ce:surname>Caprais</ce:surname><ce:given-name>M.C.</ce:given-name></sb:author><sb:author><ce:surname>Gente</ce:surname><ce:given-name>P.</ce:given-name></sb:author><sb:author><ce:surname>Gueneley</ce:surname><ce:given-name>S.</ce:given-name></sb:author><sb:author><ce:surname>Harmegnies</ce:surname><ce:given-name>F.</ce:given-name></sb:author><sb:author><ce:surname>Lagabrielle</ce:surname><ce:given-name>Y.</ce:given-name></sb:author><sb:author><ce:surname>Lapouille</ce:surname><ce:given-name>A.</ce:given-name></sb:author><sb:author><ce:surname>Lefe`vre</ce:surname><ce:given-name>C.</ce:given-name></sb:author><sb:author><ce:surname>Maillet</ce:surname><ce:given-name>P.</ce:given-name></sb:author><sb:author><ce:surname>Maze´</ce:surname><ce:given-name>J.P.</ce:given-name></sb:author><sb:author><ce:surname>Ondre´as</ce:surname><ce:given-name>H.</ce:given-name></sb:author><sb:author><ce:surname>Schaaf</ce:surname><ce:given-name>A.</ce:given-name></sb:author><sb:author><ce:surname>Singh</ce:surname><ce:given-name>S.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Accre´tion oce´anique et de´formation dans la partie me´ridionale du bassin Nord Fidjien: re´sultats pre´liminaires de la campagne oce´anographique SEAPSO III du N.O. Jean Charcot (De´cembre 1985)</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>C.R. Acad. Sci. Paris</sb:maintitle></sb:title><sb:volume-nr>306</sb:volume-nr></sb:series><sb:date>1986</sb:date></sb:issue><sb:pages><sb:first-page>971</sb:first-page><sb:last-page>978</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib3"><ce:label>Auzende et al., 1988a</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Auzende</ce:surname><ce:given-name>J.M.</ce:given-name></sb:author><sb:author><ce:surname>Eissen</ce:surname><ce:given-name>J.P.</ce:given-name></sb:author><sb:author><ce:surname>Gente</ce:surname><ce:given-name>P.</ce:given-name></sb:author><sb:author><ce:surname>Lafoy</ce:surname><ce:given-name>Y.</ce:given-name></sb:author><sb:author><ce:surname>Lagabrielle</ce:surname><ce:given-name>Y.</ce:given-name></sb:author><sb:author><ce:surname>Schaaf</ce:surname><ce:given-name>A.</ce:given-name></sb:author><sb:author><ce:surname>Charlou</ce:surname><ce:given-name>J.L.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>The accretion system of the central part of the North Fiji Basin (SW Pacific) between 16°S and 21°S (SEAPSO Leg 3 cruise — Dec 1985)</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Tectonophysics</sb:maintitle></sb:title><sb:volume-nr>146</sb:volume-nr></sb:series><sb:date>1988</sb:date></sb:issue><sb:pages><sb:first-page>317</sb:first-page><sb:last-page>351</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib4"><ce:label>Auzende et al., 1988b</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Auzende</ce:surname><ce:given-name>J.M.</ce:given-name></sb:author><sb:author><ce:surname>Honza</ce:surname><ce:given-name>E.</ce:given-name></sb:author><sb:author><ce:surname>the Scientific Party of the Kaiyo 87 Cruise</ce:surname></sb:author></sb:authors><sb:title><sb:maintitle>L'accre´tion re´cente dans le Bassin Nord-Fidjien: premiers re´sultats de la campagne franco-japonaise Kaiyo 87</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>C.R. Acad. Sci. Paris</sb:maintitle></sb:title><sb:volume-nr>306</sb:volume-nr></sb:series><sb:issue-nr>II</sb:issue-nr><sb:date>1988</sb:date></sb:issue><sb:pages><sb:first-page>971</sb:first-page><sb:last-page>978</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib5"><ce:label>Auzende et al., 1988c</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Auzende</ce:surname><ce:given-name>J.M.</ce:given-name></sb:author><sb:author><ce:surname>Lafoy</ce:surname><ce:given-name>Y.</ce:given-name></sb:author><sb:author><ce:surname>Marsset</ce:surname><ce:given-name>B.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Recent geodynamic evolution of the North Fiji Basin (SW Pacific)</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Geology</sb:maintitle></sb:title><sb:volume-nr>16</sb:volume-nr></sb:series><sb:date>1988</sb:date></sb:issue><sb:pages><sb:first-page>925</sb:first-page><sb:last-page>929</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib6"><ce:label>Bender et al., 1978</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Bender</ce:surname><ce:given-name>J.F.</ce:given-name></sb:author><sb:author><ce:surname>Hodges</ce:surname><ce:given-name>F.N.</ce:given-name></sb:author><sb:author><ce:surname>Bence</ce:surname><ce:given-name>A.E.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Petrogenesis of basalts from the project FAMOUS area: Experimental study from 0 to 15 kbar</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Earth Planet. Sci. Lett.</sb:maintitle></sb:title><sb:volume-nr>41</sb:volume-nr></sb:series><sb:date>1978</sb:date></sb:issue><sb:pages><sb:first-page>277</sb:first-page><sb:last-page>302</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib7"><ce:label>Brocher, 1985</ce:label><sb:reference><sb:host><sb:edited-book><sb:editors><sb:editor><ce:surname>Brocher</ce:surname><ce:given-name>T.H.</ce:given-name></sb:editor></sb:editors><sb:title><sb:maintitle>Investigations of the Northern Melanesian Borderland</sb:maintitle></sb:title><sb:book-series><sb:series><sb:title><sb:maintitle>Circum-Pacific Council for Energy and Mineral Resources, Earth Science Series</sb:maintitle></sb:title><sb:volume-nr>3</sb:volume-nr></sb:series></sb:book-series><sb:date>1985</sb:date><sb:publisher><sb:name>CPCEMR</sb:name><sb:location>Houston, Tex</sb:location></sb:publisher></sb:edited-book><sb:pages><sb:first-page>199</sb:first-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib8"><ce:label>Bryan, 1983</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Bryan</ce:surname><ce:given-name>W.B.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Systematics of modal phenocryst assemblages in submarine basalts: Petrologic implications</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Contrib. Mineral. Petrol.</sb:maintitle></sb:title><sb:volume-nr>83</sb:volume-nr></sb:series><sb:date>1983</sb:date></sb:issue><sb:pages><sb:first-page>62</sb:first-page><sb:last-page>74</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib9"><ce:label>Charvis and Pelletier, 1989</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Charvis</ce:surname><ce:given-name>P.</ce:given-name></sb:author><sb:author><ce:surname>Pelletier</ce:surname><ce:given-name>B.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>The northern New Hebrides back-arc troughs: history and relation to the North Fiji Basin based on tectonic and magnetic studies</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Tectonophysics</sb:maintitle></sb:title><sb:volume-nr>170</sb:volume-nr></sb:series><sb:date>1989</sb:date></sb:issue><sb:pages><sb:first-page>259</sb:first-page><sb:last-page>277</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib10"><ce:label>Chase, 1971</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Chase</ce:surname><ce:given-name>C.G.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Tectonic history of the Fiji plateau</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Geol. Soc. Am. Bull.</sb:maintitle></sb:title><sb:volume-nr>82</sb:volume-nr></sb:series><sb:date>1971</sb:date></sb:issue><sb:pages><sb:first-page>3087</sb:first-page><sb:last-page>3110</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib11"><ce:label>Cherkis, 1980</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Cherkis</ce:surname><ce:given-name>N.Z.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Aeromagnetic investigations and sea-floor spreading history in the Lau basin and northern Fiji plateau</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>UN ESCAP, CCOP/SOPAC, Tech. Bull.</sb:maintitle></sb:title><sb:volume-nr>3</sb:volume-nr></sb:series><sb:date>1980</sb:date></sb:issue><sb:pages><sb:first-page>37</sb:first-page><sb:last-page>45</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib12"><ce:label>Craig et al., 1987</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Craig</ce:surname><ce:given-name>H.</ce:given-name></sb:author><sb:author><ce:surname>Poreda</ce:surname><ce:given-name>R.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Data report, Papatua expedition, legs V and VI</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Scripps Ref. Ser.</sb:maintitle></sb:title><sb:volume-nr>87</sb:volume-nr></sb:series><sb:date>1987</sb:date></sb:issue><sb:pages><sb:first-page>14</sb:first-page></sb:pages></sb:host></sb:reference><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Craig</ce:surname><ce:given-name>H.</ce:given-name></sb:author><sb:author><ce:surname>Poreda</ce:surname><ce:given-name>R.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Data report, Papatua expedition, legs V and VI</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Scripps Ref. Ser.</sb:maintitle></sb:title><sb:volume-nr>87</sb:volume-nr></sb:series><sb:date>1987</sb:date></sb:issue><sb:pages><sb:first-page>80</sb:first-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib13"><ce:label>Drake, 1976</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Drake</ce:surname><ce:given-name>M.J.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Plagioclase-melt equilibria</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Geochim. Cosmochim. Acta</sb:maintitle></sb:title><sb:volume-nr>40</sb:volume-nr></sb:series><sb:date>1976</sb:date></sb:issue><sb:pages><sb:first-page>457</sb:first-page><sb:last-page>465</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib14"><ce:label>Eissen et al., 1989</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Eissen</ce:surname><ce:given-name>J.P.</ce:given-name></sb:author><sb:author><ce:surname>Juteau</ce:surname><ce:given-name>T.</ce:given-name></sb:author><sb:author><ce:surname>Dupre´</ce:surname><ce:given-name>B.</ce:given-name></sb:author><sb:author><ce:surname>Joron</ce:surname><ce:given-name>J.L.</ce:given-name></sb:author><sb:author><ce:surname>Humler</ce:surname><ce:given-name>E.</ce:given-name></sb:author><sb:author><ce:surname>Al'mukhamedov</ce:surname><ce:given-name>A.I.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Petrology and geochemistry of basalts from the Red Sea rift at 18° north</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>J. Petrol.</sb:maintitle></sb:title><sb:volume-nr>30</sb:volume-nr></sb:series><sb:date>1989</sb:date></sb:issue><sb:pages><sb:first-page>791</sb:first-page><sb:last-page>839</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib15"><ce:label>Eissen et al., 1990</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Eissen</ce:surname><ce:given-name>J.P.</ce:given-name></sb:author><sb:author><ce:surname>Morvan</ce:surname><ce:given-name>G.</ce:given-name></sb:author><sb:author><ce:surname>Lefe`vre</ce:surname><ce:given-name>C.</ce:given-name></sb:author><sb:author><ce:surname>Maillet</ce:surname><ce:given-name>P.</ce:given-name></sb:author><sb:author><ce:surname>Urabe</ce:surname><ce:given-name>T.</ce:given-name></sb:author><sb:author><ce:surname>Auzende</ce:surname><ce:given-name>J.M.</ce:given-name></sb:author><sb:author><ce:surname>Honza</ce:surname><ce:given-name>E.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Pe´trologie et ge´ochimie de la zone d'accre´tion du centre du Bassin Nord Fidjien (SW Pacifique)</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>C.R. Acad. Sci. Paris</sb:maintitle></sb:title><sb:volume-nr>310</sb:volume-nr></sb:series><sb:issue-nr>II</sb:issue-nr><sb:date>1990</sb:date></sb:issue><sb:pages><sb:first-page>771</sb:first-page><sb:last-page>778</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib16"><ce:label>Falvey, 1978</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Falvey</ce:surname><ce:given-name>D.A.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Analysis of paleomagnetic data from the New Hebrides</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Aust. Soc. Explor. Geophys. Bull.</sb:maintitle></sb:title><sb:volume-nr>9</sb:volume-nr></sb:series><sb:date>1978</sb:date></sb:issue><sb:pages><sb:first-page>117</sb:first-page><sb:last-page>123</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib17"><ce:label>Gente, 1987</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Gente</ce:surname><ce:given-name>P.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Etude morphostructurale comparative de dorsales oce´aniquesa`taux d'expansion varie´s</sb:maintitle></sb:title></sb:contribution><sb:host><sb:edited-book><sb:title><sb:maintitle>Sche´ma d'e´volution morphologique de l'axe de dorsales: liaison avec l'hydrothermalisme</sb:maintitle></sb:title><sb:book-series><sb:series><sb:title><sb:maintitle>The`se</sb:maintitle></sb:title></sb:series></sb:book-series><sb:date>1987</sb:date><sb:publisher><sb:name>Univ. Bretagne Occidentale</sb:name><sb:location>Brest</sb:location></sb:publisher></sb:edited-book><sb:pages><sb:first-page>371</sb:first-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib18"><ce:label>Grove and Bryan, 1983</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Grove</ce:surname><ce:given-name>T.L.</ce:given-name></sb:author><sb:author><ce:surname>Bryan</ce:surname><ce:given-name>W.B.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Fractionation of pyroxene phyric MORB at low pressure: an experimental study</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Contrib. Mineral. Petrol.</sb:maintitle></sb:title><sb:volume-nr>84</sb:volume-nr></sb:series><sb:date>1983</sb:date></sb:issue><sb:pages><sb:first-page>293</sb:first-page><sb:last-page>309</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib19"><ce:label>Hawkins and Melchior, 1985</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Hawkins</ce:surname><ce:given-name>J.W.</ce:given-name></sb:author><sb:author><ce:surname>Melchior</ce:surname><ce:given-name>J.T.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Petrology of Mariana Trough and Lau Basin basalts</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>J. Geophys. Res.</sb:maintitle></sb:title><sb:volume-nr>90</sb:volume-nr></sb:series><sb:date>1985</sb:date></sb:issue><sb:pages><sb:first-page>11431</sb:first-page><sb:last-page>11468</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib20"><ce:label>Hey, 1977</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Hey</ce:surname><ce:given-name>R.N.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>A new class of “pseudofaults” and their bearing on plate tectonics: a propagating rift model</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Earth Planet. Sci. Lett.</sb:maintitle></sb:title><sb:volume-nr>37</sb:volume-nr></sb:series><sb:date>1977</sb:date></sb:issue><sb:pages><sb:first-page>321</sb:first-page><sb:last-page>325</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib21"><ce:label>Irving and Frey, 1984</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Irving</ce:surname><ce:given-name>A.J.</ce:given-name></sb:author><sb:author><ce:surname>Frey</ce:surname><ce:given-name>F.A.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Trace element abundances in megacrysts and their host basalts: constraints on partition coefficients and megacryst genesis</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Geochim. Cosmochim. Acta</sb:maintitle></sb:title><sb:volume-nr>48</sb:volume-nr></sb:series><sb:date>1984</sb:date></sb:issue><sb:pages><sb:first-page>1201</sb:first-page><sb:last-page>1221</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib22"><ce:label>Karig, 1971</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Karig</ce:surname><ce:given-name>D.E.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Origin and development of marginal basins in the western Pacific</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>J. Geophys. Res.</sb:maintitle></sb:title><sb:volume-nr>76</sb:volume-nr></sb:series><sb:date>1971</sb:date></sb:issue><sb:pages><sb:first-page>2542</sb:first-page><sb:last-page>2561</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib23"><ce:label>Karig, 1974</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Karig</ce:surname><ce:given-name>D.E.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Evolution of arc systems in the western Pacific</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Annu. Rev. Earth Sci.</sb:maintitle></sb:title><sb:volume-nr>2</sb:volume-nr></sb:series><sb:date>1974</sb:date></sb:issue><sb:pages><sb:first-page>51</sb:first-page><sb:last-page>75</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib24"><ce:label>Kroenke, 1984</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Kroenke</ce:surname><ce:given-name>L.W.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Cenozoic tectonic development of the southwest Pacific</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>UN ESCAP, CCOP/SOPAC, Tech. Bull.</sb:maintitle></sb:title><sb:volume-nr>6</sb:volume-nr></sb:series><sb:date>1984</sb:date></sb:issue><sb:pages><sb:first-page>122</sb:first-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib25"><ce:label>Kroenke and Eade, 1991</ce:label><sb:reference><sb:host><sb:edited-book><sb:editors><sb:editor><ce:surname>Kroenke</ce:surname><ce:given-name>L.W.</ce:given-name></sb:editor><sb:editor><ce:surname>Eade</ce:surname><ce:given-name>J.V.</ce:given-name></sb:editor></sb:editors><sb:title><sb:maintitle>Basin Formation, Ridge Crest Processes and Metallogenesis in the North Fiji Basin</sb:maintitle></sb:title><sb:book-series><sb:series><sb:title><sb:maintitle>Circum-Pacific Council for Energy and Mineral Resources, Earth Science Series</sb:maintitle></sb:title><sb:volume-nr>Vol. 12</sb:volume-nr></sb:series></sb:book-series><sb:date>1991</sb:date></sb:edited-book></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib26"><ce:label>Kroenke and Shipboard Scientific Party, 1987</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Kroenke</ce:surname><ce:given-name>L.W.</ce:given-name></sb:author><sb:author><ce:surname>Shipboard Scientific Party</ce:surname></sb:author></sb:authors><sb:title><sb:maintitle>Cruise report</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:title><sb:maintitle>CCOP/SOPAC North Fiji Basin expedition</sb:maintitle></sb:title><sb:series><sb:title><sb:maintitle>R/V Moana Wave cruise MW 87-01</sb:maintitle></sb:title></sb:series><sb:date>1987</sb:date></sb:issue><sb:pages><sb:first-page>37</sb:first-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib27"><ce:label>Lafoy, 1989</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Lafoy</ce:surname><ce:given-name>Y.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Evolution ge´odynamique des bassins marginaux Nord-Fidjien et de Lau (Sud-Ouest Pacifique)</sb:maintitle></sb:title></sb:contribution><sb:host><sb:edited-book><sb:book-series><sb:series><sb:title><sb:maintitle>The`se,</sb:maintitle></sb:title></sb:series></sb:book-series><sb:date>1989</sb:date><sb:publisher><sb:name>Univ. Bretagne Occidentale</sb:name><sb:location>Brest</sb:location></sb:publisher></sb:edited-book><sb:pages><sb:first-page>261</sb:first-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib28"><ce:label>Lafoy et al., 1987</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Lafoy</ce:surname><ce:given-name>Y.</ce:given-name></sb:author><sb:author><ce:surname>Auzende</ce:surname><ce:given-name>J.M.</ce:given-name></sb:author><sb:author><ce:surname>Gente</ce:surname><ce:given-name>P.</ce:given-name></sb:author><sb:author><ce:surname>Eissen</ce:surname><ce:given-name>J.P.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>L'extre´mite´occidentale de la zone de fracture fidjienne et le point triple de 16°40′S: Re´sultats du Leg III de la campagne SEAPSO du N.O. Jean Charcot (De´cembre 1985) dans le bassin Nord-Fidjien (SW Pacifique)</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>C.R. Acad. Sci. Paris</sb:maintitle></sb:title><sb:volume-nr>304(II)</sb:volume-nr></sb:series><sb:issue-nr>3</sb:issue-nr><sb:date>1987</sb:date></sb:issue><sb:pages><sb:first-page>147</sb:first-page><sb:last-page>152</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib29"><ce:label>Larue et al., 1982</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Larue</ce:surname><ce:given-name>M.B.</ce:given-name></sb:author><sb:author><ce:surname>Pontoise</ce:surname><ce:given-name>B.</ce:given-name></sb:author><sb:author><ce:surname>Malahoff</ce:surname><ce:given-name>A.</ce:given-name></sb:author><sb:author><ce:surname>Lapouille</ce:surname><ce:given-name>A.</ce:given-name></sb:author><sb:author><ce:surname>Latham</ce:surname><ce:given-name>G.V.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Bassins marginaux actifs du sud-ouest Pacifique: plateau Nord-Fidjien, bassin de Lau</sb:maintitle></sb:title></sb:contribution><sb:host><sb:edited-book><sb:editors><sb:editor><ce:surname>Equipe de Ge´ologie-Ge´ophysique du Centre ORSTOM de Noume´a</ce:surname></sb:editor></sb:editors><sb:title><sb:maintitle>Contributiona`l'Etude Ge´odynamique du Sud-Ouest Pacifique</sb:maintitle></sb:title><sb:book-series><sb:series><sb:title><sb:maintitle>Trav. Doc. ORSTOM</sb:maintitle></sb:title><sb:volume-nr>147</sb:volume-nr></sb:series></sb:book-series><sb:date>1982</sb:date></sb:edited-book><sb:pages><sb:first-page>363</sb:first-page><sb:last-page>406</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib30"><ce:label>Louat and Pelletier, 1989</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Louat</ce:surname><ce:given-name>R.</ce:given-name></sb:author><sb:author><ce:surname>Pelletier</ce:surname><ce:given-name>B.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Seismotectonics and present-day relative plate motions in the New Hebrides-North Fiji basin region</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Tectonophysics</sb:maintitle></sb:title><sb:volume-nr>167</sb:volume-nr></sb:series><sb:date>1989</sb:date></sb:issue><sb:pages><sb:first-page>41</sb:first-page><sb:last-page>55</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib31"><ce:label>Maillet et al., 1986</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Maillet</ce:surname><ce:given-name>P.</ce:given-name></sb:author><sb:author><ce:surname>Eissen</ce:surname><ce:given-name>J.P.</ce:given-name></sb:author><sb:author><ce:surname>Lapouille</ce:surname><ce:given-name>A.</ce:given-name></sb:author><sb:author><ce:surname>Monzier</ce:surname><ce:given-name>M.</ce:given-name></sb:author><sb:author><ce:surname>Baleivanualala</ce:surname><ce:given-name>V.</ce:given-name></sb:author><sb:author><ce:surname>Butscher</ce:surname><ce:given-name>J.</ce:given-name></sb:author><sb:author><ce:surname>Gallois</ce:surname><ce:given-name>F.</ce:given-name></sb:author><sb:author><ce:surname>Lardy</ce:surname><ce:given-name>M.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>La dorsale active du Bassin Nord-Fidjien entre 20.000°S et 20.53°S: Signature magne´tique et morphologie</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>C.R. Acad. Sci. Paris</sb:maintitle></sb:title><sb:volume-nr>302</sb:volume-nr></sb:series><sb:issue-nr>II</sb:issue-nr><sb:date>1986</sb:date></sb:issue><sb:pages><sb:first-page>135</sb:first-page><sb:last-page>140</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib32"><ce:label>Maillet et al., 1989</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Maillet</ce:surname><ce:given-name>P.</ce:given-name></sb:author><sb:author><ce:surname>Monzier</ce:surname><ce:given-name>M.</ce:given-name></sb:author><sb:author><ce:surname>Eissen</ce:surname><ce:given-name>J.P.</ce:given-name></sb:author><sb:author><ce:surname>Louat</ce:surname><ce:given-name>R.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Geodynamics of an arc-ridge junction: The New Hebrides arc/North Fiji Basin case</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Tectonophysics</sb:maintitle></sb:title><sb:volume-nr>165</sb:volume-nr></sb:series><sb:date>1989</sb:date></sb:issue><sb:pages><sb:first-page>251</sb:first-page><sb:last-page>268</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib33"><ce:label>Malahoff et al., 1982</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Malahoff</ce:surname><ce:given-name>A.</ce:given-name></sb:author><sb:author><ce:surname>Feden</ce:surname><ce:given-name>R.H.</ce:given-name></sb:author><sb:author><ce:surname>Fleming</ce:surname><ce:given-name>H.S.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Magnetic anomalies and tectonic fabric of marginal basins north of New Zealand</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>J. Geophys. Res.</sb:maintitle></sb:title><sb:volume-nr>87</sb:volume-nr></sb:series><sb:date>1982</sb:date></sb:issue><sb:pages><sb:first-page>4109</sb:first-page><sb:last-page>4125</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib34"><ce:label>Monjaret et al., 1987</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Monjaret</ce:surname><ce:given-name>M.C.</ce:given-name></sb:author><sb:author><ce:surname>Bellon</ce:surname><ce:given-name>H.</ce:given-name></sb:author><sb:author><ce:surname>Maillet</ce:surname><ce:given-name>P.</ce:given-name></sb:author><sb:author><ce:surname>Re´cy</ce:surname><ce:given-name>J.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Le volcanisme des fosse´s arrie`re-arc des Nouvelles-He´brides (campagne SEAPSO Leg 2 du N/O Jean Charcot dans le Pacifique Sud-Ouest): Datations K-Ar et donne´es pe´trologiques pre´liminaires</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>C.R. Acad. Sci. Paris</sb:maintitle></sb:title><sb:volume-nr>305</sb:volume-nr></sb:series><sb:issue-nr>II</sb:issue-nr><sb:date>1987</sb:date></sb:issue><sb:pages><sb:first-page>605</sb:first-page><sb:last-page>609</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib35"><ce:label>Nohara et al., 1989</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Nohara</ce:surname><ce:given-name>M.</ce:given-name></sb:author><sb:author><ce:surname>Urabe</ce:surname><ce:given-name>T.</ce:given-name></sb:author><sb:author><ce:surname>Joshima</ce:surname><ce:given-name>M.</ce:given-name></sb:author><sb:author><ce:surname>Honza</ce:surname><ce:given-name>E.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>REE and isotope constraints on the origin of back-arc basalts in the North Fiji Basin</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>CCOP/SOPAC Misc. Rep.</sb:maintitle></sb:title><sb:volume-nr>79</sb:volume-nr></sb:series><sb:date>1989</sb:date></sb:issue><sb:pages><sb:first-page>95</sb:first-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib36"><ce:label>Pelletier et al., 1988</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Pelletier</ce:surname><ce:given-name>B.</ce:given-name></sb:author><sb:author><ce:surname>Charvis</ce:surname><ce:given-name>P.</ce:given-name></sb:author><sb:author><ce:surname>Daniel</ce:surname><ce:given-name>J.</ce:given-name></sb:author><sb:author><ce:surname>Hello</ce:surname><ce:given-name>Y.</ce:given-name></sb:author><sb:author><ce:surname>Jamet</ce:surname><ce:given-name>F.</ce:given-name></sb:author><sb:author><ce:surname>Louat</ce:surname><ce:given-name>R.</ce:given-name></sb:author><sb:author><ce:surname>Nanau</ce:surname><ce:given-name>P.</ce:given-name></sb:author><sb:author><ce:surname>Rigolot</ce:surname><ce:given-name>P.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Structure et line´ations magne´tiques dans le coin Nord-Ouest du bassin Nord-Fidjien: re´sultats pre´liminaires de la campagne Eva 14 (aouˆt 1987)</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>C.R. Acad. Sci. Paris</sb:maintitle></sb:title><sb:volume-nr>306</sb:volume-nr></sb:series><sb:issue-nr>II</sb:issue-nr><sb:date>1988</sb:date></sb:issue><sb:pages><sb:first-page>1247</sb:first-page><sb:last-page>1254</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib37"><ce:label>Presnall et al., 1979</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Presnall</ce:surname><ce:given-name>D.C.</ce:given-name></sb:author><sb:author><ce:surname>Dixon</ce:surname><ce:given-name>J.R.</ce:given-name></sb:author><sb:author><ce:surname>O'Donnell</ce:surname><ce:given-name>T.H.</ce:given-name></sb:author><sb:author><ce:surname>Dixon</ce:surname><ce:given-name>S.A.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Generation of mid-ocean ridges tholeiites</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>J. Petrol.</sb:maintitle></sb:title><sb:volume-nr>20</sb:volume-nr></sb:series><sb:date>1979</sb:date></sb:issue><sb:pages><sb:first-page>3</sb:first-page><sb:last-page>35</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib38"><ce:label>Roedder and Emslie, 1970</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Roedder</ce:surname><ce:given-name>P.L.</ce:given-name></sb:author><sb:author><ce:surname>Emslie</ce:surname><ce:given-name>R.F.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Olivine-liquid equilibrium</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Contrib. Mineral. Petrol.</sb:maintitle></sb:title><sb:volume-nr>29</sb:volume-nr></sb:series><sb:date>1970</sb:date></sb:issue><sb:pages><sb:first-page>275</sb:first-page><sb:last-page>289</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib39"><ce:label>Romeur, 1987</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Romeur</ce:surname><ce:given-name>M.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Variabilite´locale de la composition des MORB. Etude du rapport K/Ti dans les verres basaltiques des axes des rides Me´dio-Atlantique et Est-Pacifique</sb:maintitle></sb:title></sb:contribution><sb:host><sb:edited-book><sb:date>1987</sb:date><sb:publisher><sb:name>Rapp. D.E.A., Univ. Bretagne Occidentale</sb:name><sb:location>Brest</sb:location></sb:publisher></sb:edited-book><sb:pages><sb:first-page>91</sb:first-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib40"><ce:label>Ruellan et al., 1989</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Ruellan</ce:surname><ce:given-name>E.</ce:given-name></sb:author><sb:author><ce:surname>Auzende</ce:surname><ce:given-name>J.M.</ce:given-name></sb:author><sb:author><ce:surname>Honza</ce:surname><ce:given-name>E.</ce:given-name></sb:author><sb:et-al></sb:et-al></sb:authors><sb:title><sb:maintitle>L'accre´tion dans le bassin Nord Fidjien me´ridional: premiers re´sultats de la campagne franco-japonaise STARMER/KAIYO 88</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>C.R. Acad. Sci. Paris</sb:maintitle></sb:title><sb:volume-nr>309</sb:volume-nr></sb:series><sb:date>1989</sb:date></sb:issue><sb:pages><sb:first-page>1247</sb:first-page><sb:last-page>1254</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib41"><ce:label>Saunders and Tarney, 1984</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Saunders</ce:surname><ce:given-name>A.D.</ce:given-name></sb:author><sb:author><ce:surname>Tarney</ce:surname><ce:given-name>J.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Geochemical characteristics of basaltic volcanism within back-arc basins</sb:maintitle></sb:title></sb:contribution><sb:host><sb:edited-book><sb:editors><sb:editor><ce:surname>Kokelaar</ce:surname><ce:given-name>B.P.</ce:given-name></sb:editor><sb:editor><ce:surname>Holwells</ce:surname><ce:given-name>M.F.</ce:given-name></sb:editor></sb:editors><sb:title><sb:maintitle>Marginal Basins: Geology, Volcanism and Associated Sedimentary and Tectonic Processes in Modern and Ancient Marginal Basins</sb:maintitle></sb:title><sb:date>1984</sb:date><sb:publisher><sb:name>Blackwell</sb:name><sb:location>Oxford</sb:location></sb:publisher></sb:edited-book><sb:pages><sb:first-page>59</sb:first-page><sb:last-page>76</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib42"><ce:label>Sinton and Fryer, 1987</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Sinton</ce:surname><ce:given-name>J.</ce:given-name></sb:author><sb:author><ce:surname>Fryer</ce:surname><ce:given-name>P.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Mariana Trough lavas from 18°N: Implications for the origin of back-arc basin basalts</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>J. Geophys. Res.</sb:maintitle></sb:title><sb:volume-nr>92</sb:volume-nr></sb:series><sb:date>1987</sb:date></sb:issue><sb:pages><sb:first-page>12782</sb:first-page><sb:last-page>12802</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib43"><ce:label>Sinton et al., 1991</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Sinton</ce:surname><ce:given-name>J.</ce:given-name></sb:author><sb:author><ce:surname>Price</ce:surname><ce:given-name>R.C.</ce:given-name></sb:author><sb:author><ce:surname>Johnson</ce:surname><ce:given-name>K.T.M.</ce:given-name></sb:author><sb:author><ce:surname>Staudigel</ce:surname><ce:given-name>H.</ce:given-name></sb:author><sb:author><ce:surname>Zindler</ce:surname><ce:given-name>A.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Petrology and geochemistry of submarine lavas from the Lau and North Fiji Basins</sb:maintitle></sb:title></sb:contribution><sb:host><sb:edited-book><sb:book-series><sb:editors><sb:editor><ce:surname>Kroenke</ce:surname><ce:given-name>L.W.</ce:given-name></sb:editor><sb:editor><ce:surname>Eade</ce:surname><ce:given-name>J.V.</ce:given-name></sb:editor></sb:editors><sb:series><sb:title><sb:maintitle>Basin Formation, Ridge Crest Processes and Metallogenesis in the North Fiji Basin</sb:maintitle></sb:title><sb:volume-nr>Vol. 12</sb:volume-nr></sb:series></sb:book-series><sb:date>1991</sb:date><sb:publisher><sb:name>(Circum-Pacific Council for Energy and Mineral Resources, Earth Science Series, 3)</sb:name></sb:publisher></sb:edited-book><sb:pages><sb:first-page>155</sb:first-page><sb:last-page>177</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib44"><ce:label>Stakes et al., 1985</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Stakes</ce:surname><ce:given-name>D.S.</ce:given-name></sb:author><sb:author><ce:surname>Shervais</ce:surname><ce:given-name>J.W.</ce:given-name></sb:author><sb:author><ce:surname>Hopson</ce:surname><ce:given-name>C.C.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>The volcano-tectonic cycle of the FAMOUS and AMAR valleys, Mid-Atlantic ridge (36°47′N): evidence from basalt glass and compositional variations for a steady state magma chamber beneath the valley midsections, AMAR 3</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>J. Geophys. Res.</sb:maintitle></sb:title><sb:volume-nr>89</sb:volume-nr></sb:series><sb:date>1985</sb:date></sb:issue><sb:pages><sb:first-page>6995</sb:first-page><sb:last-page>7029</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib45"><ce:label>Staudigel and Bryan, 1981</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Staudigel</ce:surname><ce:given-name>H.</ce:given-name></sb:author><sb:author><ce:surname>Bryan</ce:surname><ce:given-name>W.B.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Contrasted glass-whole rock compositions and phenocryst redistribution, IPOD sites 417 and 418</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Contrib. Mineral. Petrol.</sb:maintitle></sb:title><sb:volume-nr>78</sb:volume-nr></sb:series><sb:date>1981</sb:date></sb:issue><sb:pages><sb:first-page>255</sb:first-page><sb:last-page>262</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib46"><ce:label>Sun and McDonough, 1989</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Sun</ce:surname><ce:given-name>S.S.</ce:given-name></sb:author><sb:author><ce:surname>McDonough</ce:surname><ce:given-name>W.F.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes</sb:maintitle></sb:title></sb:contribution><sb:host><sb:edited-book><sb:editors><sb:editor><ce:surname>Saunders</ce:surname><ce:given-name>A.D.</ce:given-name></sb:editor><sb:editor><ce:surname>Norry</ce:surname><ce:given-name>M.J.</ce:given-name></sb:editor></sb:editors><sb:title><sb:maintitle>Magmatism in the Ocean Basins</sb:maintitle></sb:title><sb:book-series><sb:series><sb:title><sb:maintitle>Geol. Soc. Spec. Publ.</sb:maintitle></sb:title><sb:volume-nr>42</sb:volume-nr></sb:series></sb:book-series><sb:date>1989</sb:date></sb:edited-book><sb:pages><sb:first-page>313</sb:first-page><sb:last-page>345</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference><ce:bib-reference id="bib47"><ce:label>Walker et al., 1979</ce:label><sb:reference><sb:contribution><sb:authors><sb:author><ce:surname>Walker</ce:surname><ce:given-name>D.</ce:given-name></sb:author><sb:author><ce:surname>Shibata</ce:surname><ce:given-name>T.</ce:given-name></sb:author><sb:author><ce:surname>DeLong</ce:surname><ce:given-name>S.E.</ce:given-name></sb:author></sb:authors><sb:title><sb:maintitle>Abyssal tholeiites from the Oceanographer Fracture zone. II: Phase equilibria and mixing</sb:maintitle></sb:title></sb:contribution><sb:host><sb:issue><sb:series><sb:title><sb:maintitle>Contrib. Mineral. Petrol.</sb:maintitle></sb:title><sb:volume-nr>70</sb:volume-nr></sb:series><sb:date>1979</sb:date></sb:issue><sb:pages><sb:first-page>111</sb:first-page><sb:last-page>125</sb:last-page></sb:pages></sb:host></sb:reference></ce:bib-reference></ce:bibliography-sec></ce:bibliography></tail></article></istex:document></istex:metadataXml><mods version="3.6"><titleInfo lang="en"><title>Petrology and geochemistry of the central North Fiji Basin spreading centre (Southwest Pacific) between 16°S and 22°S</title></titleInfo><titleInfo type="alternative" lang="en" contentType="CDATA"><title>Petrology and geochemistry of the central North Fiji Basin spreading centre (Southwest Pacific) between 16°S and 22°S</title></titleInfo><name type="personal"><namePart type="given">Jean-Philippe</namePart><namePart type="family">Eissen</namePart><affiliation>Centre ORSTOM, BP A5, Noume´a Cedex, New Caledonia</affiliation><affiliation>1Member of GDR 910, “Genese et Evolution des Domaines Oce´aniques, Brest</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">Christian</namePart><namePart type="family">Lefe`vre</namePart><affiliation>Universite´des Sciences et Techniques de Lille, Sciences de la Terre, 59655 Villeneuve d'Ascq Cedex, France</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">Patrick</namePart><namePart type="family">Maillet</namePart><affiliation>ORSTOM, La Trobe University, Geology Department, Bundoora, Vic. 3083, Australia</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">Gilles</namePart><namePart type="family">Morvan</namePart><affiliation>Universite´de Bretagne Occidentale, Faculte´des Sciences, 6 Avenue Le Gorgeu, 29263 Brest Cedex, France</affiliation><role><roleTerm type="text">author</roleTerm></role></name><name type="personal"><namePart type="given">Masato</namePart><namePart type="family">Nohara</namePart><affiliation>Geological Survey of Japan, Tsukuba, Ibaraki 305, Japan</affiliation><role><roleTerm type="text">author</roleTerm></role></name><typeOfResource>text</typeOfResource><genre type="research-article" displayLabel="Full-length article"></genre><originInfo><publisher>ELSEVIER</publisher><dateIssued encoding="w3cdtf">1991</dateIssued><copyrightDate encoding="w3cdtf">1991</copyrightDate></originInfo><language><languageTerm type="code" authority="iso639-2b">eng</languageTerm><languageTerm type="code" authority="rfc3066">en</languageTerm></language><physicalDescription><internetMediaType>text/html</internetMediaType></physicalDescription><abstract lang="en">Abstract: The North Fiji Basin (NFB) is a 12 m.y. old back-arc basin that has a complex multi-stage history. The presently active spreading system can be divided into four segments between 16°S and 22°S, which from north to south trend N160, N15 and N-S (the fourth segment is the N-S trending segment located near 174E). The main N-S segment is morphologically similar to other medium-rate oceanic ridges, whereas the other segments have rougher morphologies which have been severely disturbed by a triple junction at 16°45S and several instability features such as overlapping spreading centres (OSCs) and propagating rifts. The spreading rate seems to diminish from 7.8 cm/yr near 20°S to 4.6 cm/yr near 18°S. Mineralogical, pertological and geochemical data were obtained on 24 new stations located along all the four segments. The petrogenesis of the basalts collected is essentially controlled by low-pressure crystal fractionation of plagioclase±olivine±clinopyroxene (plagioclase>olivine>clinopyroxene) with 52% of the NFB basalts reaching the four-phase cotectic. Locally, some magma mixing occurs, but this is limited to magma batches of closely related composition, as might be expected to occur inside a magma reservoir. The N-S segment, which, since 3 m.y., is the only steady-state segment, is also petrologically and geochemically very comparable to other medium-rate oceanic spreading centres, producing moderately evolved LILE and LREE-depleted N-MORB. In contrast, the three other segments produce basalts of much more variable petrology and geochemistry characterized by LILE and slightly LREE-enriched magmas cf back-arc basin basalt (BABB) affinity (but not as enriched as, for example, the Mariana BABB); MORB is, however, also found on the N160, N15 and 174E segments. Diagrams using Ba, Rb, K/P and (K/Ti)N (Normalized to the chondrites) plotted against latitude clearly show along-strike variations. Beneath the recently formed segments, the mantle source is heterogeneous, and locally has some BABB affinities, whereas beneath the more steady-state N-S segment the magma source is more homogeneous, being generally depleted in LILE and REE as is the case for classical N-MORB mantle sources. Simple evolution from an early stage of BABB production to MORB described in the Lau basin and proposed for the NFB does not seem to occur. Present-day activity still produces large amounts of BABB along the less-stable and more recently created segments, and MORB was produced in the earlier stages of the development of the NFB.</abstract><relatedItem type="host"><titleInfo><title>Marine Geology</title></titleInfo><titleInfo type="abbreviated"><title>MARGO</title></titleInfo><genre type="journal">journal</genre><originInfo><dateIssued encoding="w3cdtf">199106</dateIssued></originInfo><identifier type="ISSN">0025-3227</identifier><identifier type="PII">S0025-3227(00)X0243-5</identifier><part><date>199106</date><detail type="issue"><title>The geology, geophysics and mineral resources of the South Pacific</title></detail><detail type="volume"><number>98</number><caption>vol.</caption></detail><detail type="issue"><number>2–4</number><caption>no.</caption></detail><extent unit="issue pages"><start>155</start><end>470</end></extent><extent unit="pages"><start>201</start><end>239</end></extent></part></relatedItem><identifier type="istex">596AC6B24BD49C89EFBA1A98ECB368EA4854894F</identifier><identifier type="DOI">10.1016/0025-3227(91)90104-C</identifier><identifier type="PII">0025-3227(91)90104-C</identifier><identifier type="ArticleID">9190104C</identifier><accessCondition type="use and reproduction" contentType="copyright">©1991 Elsevier Science Publishers B.V. All rights reserved</accessCondition><recordInfo><recordContentSource>ELSEVIER</recordContentSource><recordOrigin>Elsevier Science Publishers B.V. All rights reserved, ©1991</recordOrigin></recordInfo></mods></metadata><enrichments><istex:catWosTEI uri="https://api.istex.fr/document/596AC6B24BD49C89EFBA1A98ECB368EA4854894F/enrichments/catWos"><teiHeader><profileDesc><textClass><classCode scheme="WOS">GEOSCIENCES, MULTIDISCIPLINARY</classCode><classCode scheme="WOS">OCEANOGRAPHY</classCode></textClass></profileDesc></teiHeader></istex:catWosTEI></enrichments></istex></record>Pour manipuler ce document sous Unix (Dilib)
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