Large 230Th-excesses in basalts produced by partial melting of spinel lherzolite

Chemical Geology

Volumn 162, Issue 2, 2000, Pages 127-136

  Turner, Simon ^a   Blundy, Jon ^b   Wood, Bernard ^b   Hole, Malcolm ^c  

^a OPEN UNIVERSITY   (United Kingdom)

^b UNIVERSITY OF BRISTOL   (United Kingdom)

^c UNIVERSITY OF ABERDEEN   (United Kingdom)

Author keywords

Antarctic Peninsula; Mid ocean ridge basalts; Spinel lherzolite; U series isotopes

Indexed keywords

LHERZOLITE; MID-OCEAN RIDGE BASALT; PARTIAL MELTING; THORIUM ISOTOPE; URANIUM;

EID: 0034602858     PISSN: 00092541     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0009-2541(99)00127-8     Document Type: Conference Paper

References (40)

1. Ahern J.L., Turcotte D.L. Magma migration beneath an ocean ridge. Earth Planet. Sci. Lett. 45:1979;115-122.
2. Asmerom Y. Th-U fractionation and mantle structure. Earth Planet. Sci. Lett. 166:1999;163-175.
3. Asmerom Y., Edwards R.L. U-series isotope evidence for the origin of continental basalts. Earth Planet. Sci. Lett. 134:1998;1-7.
4. Barker P.F. The Cenozoic subduction history of the Pacific margin of the Antarctic Peninsula: ridge crest-trench interactions. J. Geol. Soc. Lond. 139:1982;787-801.
5. Beattie P. Uranium-thorium disequilibria and partitioning on melting of garnet peridotite. Nature. 363:1993;63-65.
6. Blundy J.D., Wood B.J. Prediction of crystal-melt partition coefficients from elastic moduli. Nature. 372:1994;452-454.
7. Blundy J.D., Falloon T.J., Wood B.J., Dalton J.A. Sodium partitioning between clinopyroxene and silicate melts. J. Geophys. Res. 100:1995;15501-15515.
8. Blundy J.D., Robinson J.A.C., Wood B.J. Heavy REE are compatible in clinopyroxene on the spinel lherzolite solidus. Earth Planet. Sci. Lett. 160:1998;493-504.
9. 230Th disequilibria data Nature. 384:1996;231-235.
10. Falloon, T.J., Green, D.H., 1988. Anhydrous partial melting of peridotite from 8 to 35 kb and the petrogenesis of MORB. J. Petrol., Spec. Lithosphere Issue, 379-414.
11. Hauri E.H., Wagner T.P., Grove T.L. Experimental and natural partitioning of Th, U, Pb and other trace elements between garnet, clinopyroxene and basaltic melts. Chem. Geol. 117:1994;149-166.
12. Hirose K., Kushiro I. Partial melting of dry peridotites at high pressures: determination of compositions of melts segregated from peridotite using aggregates of diamond. Earth Planet. Sci. Lett. 114:1993;477-489.
13. Hirose K., Kushiro I. The effect of melt segregation on polybaric mantle melting: estimation from the incremental melting experiments. Phys. Earth Planet. Inter. 107:1998;111-118.
14. Hirschmann M.M., Stolper E.M. A possible role for garnet pyroxenite in the origin of the "garnet signature" in MORB. Contrib. Mineral. Petrol. 124:1996;185-208.
15. Hirschmann M.M., Baker M.B., Stolper E.M. The effect of alkalis on the silica content of mantle-derived melts. Geochim. Cosmochim. Acta. 62:1998;883-902.
16. Hirth G., Kohlstedt D.L. Water in the oceanic upper mantle: implications for rheology, melt extraction and the evolution of the lithosphere. Earth Planet. Sci. Lett. 144:1996;93-108.
17. Hole M.J., Larter R.D. Trench-proximal volcanism following ridge crest-trench collision along the Antarctic Peninsula. Tectonics. 12:1993;897-910.
18. Hole M.J., Saunders A.D. The generation of small melt-fractions in truncated melt columns: constraints from magmas erupted above slab windows and implications for MORB genesis. Min. Mag. 60:1996;173-189.
19. Hole M.J., Kempton P.D., Millar I.L. Trace-element and isotopic characteristics of small-degree melts of the asthenosphere: evidence from the alkali basalts of the Antarctic Peninsula. Chem. Geol. 109:1993;51-68.
20. Johnson K.T.M. Experimental determination of partition coefficients for rare earth and high field-strength elements between clinopyroxene, garnet, and basaltic melt at high pressures. Contrib. Mineral. Petrol. 133:1998;60-68.
21. Klein E.M., Langmuir C.H. Global correlations of ocean ridge basalt chemistry with axial depth and crustal thickness. J. Geophys. Res. 92:1987;8089-8115.
22. Klein E.M., Langmuir C.H. Local versus global variations in ocean ridge basalt composition: a reply. J. Geophys. Res. 94:1989;4241-4252.
23. Kushiro I. Compositions of partial melts formed in mantle peridotites at high pressures and their relation to those of primitive MORB. Phys. Earth Planet. Inter. 107:1998;103-110.
24. Lundstrom, C.C., Gill, J., Williams, Q., this volume. A geochemically consistent hypothesis for MORB generation. Chem. Geol.
25. 238U disequilibrium and the melting processes beneath ridge axes Earth Planet. Sci. Lett. 72:1985;149-157.
26. McKenzie D., Bickle M.J. The volume and composition of melt generated by extension of the lithosphere. J. Petrol. 29:1988;625-679.
27. Robinson J.A.C., Wood B.J. The depth of the spinel to garnet transition at the peridotite solidus. Earth Planet. Sci. Lett. 164:1999;277-284.
28. Robinson J.A.C., Wood B.J., Blundy J.D. The beginning of melting of fertile and depleted peridotite at 1.5 GPa. Earth Planet. Sci. Lett. 155:1998;97-111.
29. Salters V.J.M. The generation of mid-ocean ridge basalts from the Hf and Nd isotope perspective. Earth Planet. Sci. Lett. 141:1996;109-123.
30. Salters V.J.M., Hart S.R. The hafnium paradox and the role of garnet in the source of mid-ocean ridge basalts. Nature. 342:1989;420-422.
31. Saltzer R.L., Humphreys E.D. Upper mantle P wave velocity structure of the eastern Snake River Plain and its relationship to geodynamic models of the region. J. Geophys. Res. 102:1997;11829-11841.
32. Shen Y., Forsyth D.W. Geochemical constraints on initial and final depths of melting beneath mid-ocean ridges. J. Geophys. Res. 100:1995;2211-2237.
33. Spiegelman M., Elliott T. Consequences of melt transport for uranium series disequilibrium in young lavas. Earth Planet. Sci. Lett. 118:1993;1-20.
34. Sun S.-s., McDonough W.F. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. Geol. Soc. London, Spec. Publ. 42:1989;313-345.
35. Toomey D.R., Wilcock W.S., Solomon S.C., Hammond W.C., Orcutt J.A. Mantle seismic structure beneath the MELT region of the East Pacific Rise from P and S wave tomography. Science. 280:1998;1224-1227.
36. 230Th disequilibria, magma petrogenesis and flux rates beneath the depleted Tonga-Kermadec island arc Geochim. Cosmochim. Acta. 61:1997;4855-4884.
37. Van Orman J.A., Grove T.L., Shimizu N. Uranium and thorium diffusion in diopside. Earth Planet. Sci. Lett. 160:1998;505-519.
38. Van Westrenen W., Blundy J., Wood B. Crystal chemical controls on trace element partitioning between garnet and anhydrous silicate melt. Am. Mineral. 84:1999;838-847.
39. Williams R.W., Gill J.B. Effects of partial melting on the uranium decay series. Geochim. Cosmochim. Acta. 53:1989;1607-1619.
40. Wood B.J., Blundy J.D., Robinson J.A.C. The role of clinopyroxene in generating U-series disequilibrium during mantle melting. Geochim. Cosmochim. Acta. 63:1999;1613-1620.