Mid-oceanic ridge basalt

Fame G (1986) Principles of Isotope Geology, Second Edition. John Wiley and Sons, New York Fleischer RL, Raabe OG (1975) Recoiling alpha-emitting nuclei. Mechanisms for uranium-series disequilibrium. Geochim Cosmochim Acta 42 973-978 Goldstein SJ, Murrell MT, Williams RW (1993) Pa and h chronology of mid-ocean ridge basalts. Earth Planet Sci Lett 115 151-159... 

Goldstein SJ, Murrell, MT, Wilhams RW (1993) Pa and h chronology of mid-ocean ridge basalts. Earth Planet Sci Lett 115 151-159... 

Salters VJM, Hart SR (1989) The hafnium paradox and the role of garnet in the source of mid-ocean-ridge basalts. Nature 342 420-422... 

Lundstrom CC (2003) Uranimn-series disequilibria in mid-ocean ridge basalts observations and models of basalt genesis. Rev Mineral Geochem 52 175-214... 

Rubin KH, Macdougall JD (1988) Ra excesses in mid-ocean-ridge basalts and mantle melting. Nature 335 158-161... 

Volpe AM, Hammond PE (1991) U- °Th- Ra disequilibria in young Mount St. Helens rocks Time constraint for magma formation and crystallization. Earth Planet Sci Lett 107 475-486 Volpe AM, Goldstein SJ (1993) Ra- °Th disequilibrium in axial and off-axis mid-ocean ridge basalts. Geochim Cosmochim Acta 57 1233-1241... 

Table 1. Summary of published U-Th-Ra-Pa data for mid-ocean ridge basalts.

Lundstrom CC, Shaw H, Ryerson F, Phinney D, Gill J, Williams Q (1994) Compositional controls on on the partitioning of U, Th, Ba, Pb, Sr and Zr between clinopyroxene and haplobasaltic melts implications for uranium series disequilibria in basalts. Earth Planet Sci Lett 128 407-423 Lnndstrom CC (2003) Uranium-series disequilibria in mid-ocean ridge basalts observations and models of basalt genesis. Rev Mineral Geochem 52 175-214... 

Although less compatible than Mg, Al apparently is still well retained by the residue during melting, which supports the presence of an aluminous phase in the residue as suggested by Johnson et al. (1990). If we knew the Al203/Mg0 ratio of the whole rock prior to melting, it would be possible to calculate that ratio in the last liquid extracted and compare its value with mid-ocean ridge basalt (MORB) values. <=... 

Chlorine isotope compositions vary by up to 15%o (Chapter 7 Stewart and Spivack 2004). These large variations in Cl isotope compositions are found in marine environments, including mid-ocean ridge basalts, seafloor and hydrothermal alteration products, and sedimentary pore... 

Mantle reservoirs. The only quasi-systematic studies of igneous materials have centered on the mantle in particular mid-ocean ridge basalts (MORE), ocean island basalts, and mantle peridotites. After reporting one MORE analysis in Chan and Edmond (1988), the first full study of MORE (Chan et al. 1992) reported three apparently imaltered Atlantic basalts and one from the East Pacific Rise, with a range in 8 Li of +3.4 to +4.7 (Fig. 5). Subsequent studies have increased the global range of samples, the diversity of bulk compositions analyzed. 

Figure 4. Radiogenic Ca enrichments measured on whole rocks as reported hy Marshall and DePaolo (1989), shown here as 8c, values with 1-sigma uncertainties and plotted versus (a) K/Ca and (h) Enj value. The inferred value for seawater is also plotted in (a). Mid-ocean ridge basalts have no measurable enrichment of Ca/ Ca relative to the initial value for the Earth (151.016), as expected for magma derived from the Earth s mantle. Many granitic rocks, especially those with high K contents and low e j values, have significantly elevated Ec, values.

Williams H, Lee D-C, Levasseur S, Teutsch N, Poitrasson R, Halliday AN (2002) Iron isotope composition of mid-ocean ridge basalts and mantle peridotites. Geochim Cosmochim Acta 66 A838... 

Doe BR (1994) Zinc, copper, and lead in mid-ocean ridge basalts and the source rock control on Zn/Pb in ocean-ridge hydrothermal deposits. Geochim Cosmochim Acta 58 2215-2223 Ehrlich S, Butler I, Halicz L, Rickard D, Oldroyd A, Matthews A (submitted) Experimental study of copper isotope fractionation between aqueous Cu(II) and covellite, CuS. Chem Geol Finney LA, O Halloran TV (2003) Transition metal speciation in the cell insights from the chemistry of metal ion receptors. Science 300 931-936... 

Marty B, Zimmermann L (1999) Volatiles (He, C, N, Ar) in mid-ocean ridge basalts assesment of shallow-level fractionation and characterization of source composition. Geochim Cosmochim Acta 63 3619-3633... 

Pichat S, Douchet C, Albarede F (2003) Zinc isotope variations in deep-sea carbonates from the eastern equatorial Pacific over the last 175 ka. Earth Planet Sci Lett 210 167-178 Pineau F, Javoy M (1983) Carbon isotopes and concentrations in mid-ocean ridge basalts. Earth Planet Sci Lett 62 239-257... 

Example 5.20 In a mid-ocean ridge basalt, one may sometimes find zonation of MgO in glass next to an olivine phenocryst. The distance of midconcentration of the profile is about 20 / m away from the interface. How would one interpret the formation of the profile ... 

Mid-oceanic ridge basalt A mafic volcanic (extrusive) rock that erupts on the ocean floor in a spreading... 

Fig. 3.4. Chondrite normalised REE patterns and mantle normalised incompatible element patterns of Intra-Apennine volcanic rocks. Patterns for mafic rocks from the Roman Province and the Virunga volcanoes (East Africa), for Enriched Mid Ocean Ridge Basalts (E-MORB) and for limestones from northern Apennines are also shown.

Fig. 4.8. (A). REE patterns of the Vulsini rocks. The ruled area encloses patterns of mafic rocks. (B) Incompatible element patterns of malic rocks from Vulsini. The pattern of the late erupted Lamone trachybasalt lava is shown in detail. Composition of Enriched Mid Ocean Ridge Basalt (E-MORB Sun and McDonough 1989) is reported for comparison.

Rocks with a composition similar to the Mid-Ocean Ridge Basalts have been recovered from the Vavilov basin (ODP Site 655 and DSDP Site 373)... 

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