What is the origin of OIB?

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What is the origin of OIB?
John Caulfield

• Identification and explanation of similarities
  and differences in isotopic ratios (Sr, Nd, Os, O
  and Pb) between OIB and MORB, Mantle and
  Continental Crust.
• Hence, which mantle components are unique to OIB,
  and which heterogeneities are the result of
  localised OIB interaction with crust and mantle.

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Sr-Nd Isotope correlations
SCLM xenolith Os concs.
DEPLETED
MORB
SCLM
OIB
ENRICHED
Modified from Hofmann 1997.
Pearson et al. 1995
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Element compatibility plot

• Greater enrichment in incompatible elements
  suggests OIB are smaller degree melts than MORB.
  Plume emplacement required for OIB?

• OIB has Nb and Pb anomalies with the same sense
  as MORB, and opposite to those of C.C. excludes
  simple two component mixing.

Modified from Hofmann 1997.
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Multi-Component mixing 1

• OIBs can be distinguished by their enrichment in
  three mantle components, EM1, EM2 and HIMU all of
  which can show elevated 187Os/188Os suggestive
  of a common source.

• All mixing arrays converge on depleted FOZO
  component that is distinct from the DMM component
  in terms of Pb concentration.

Van Keken et al. 2002
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Multi-component mixing 2

• Elevated 3He/4He of FOZO indicates primitive
  nature

• All arrays contain FOZO, but not EM1, EM2 and
  HIMU all together.

• OIB source model must reconcile supply of EM/HIMU
  components in differing proportions and
  subsequent mixing with FOZO.

Van Keken et al. 2002
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Recycling of subducted oceanic crust

• Subducted slab provides source for three enriched
  mantle components and allows for elevated
  187Os/188Os.

HIMU- Recycled oceanic crust EM1- Oceanic
lithosphere EM2- Modern sediments
187Os/188Os correlates with d18O.
d18O
d18O
Lassiter and Hauri 1998
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Koolau and Kea Components
Lassiter and Hauri 1997
Koolau displays elevated 3He consistent with
entrainment of FOZO above D
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Preservation of Heterogeneity

• Metabasaltic lithosphere transforms to Eclogite
  at approx. 100km depth.

• Increased viscosity of Eclogite(GarnetCpx)
  preserves slab heterogeneity.

• High Sm/Yb ratios in Hawaiian lavas reflect the
  presence of Garnet in their source, precluding
  generation of melts in the upper lithospheric
  mantle.

Lassiter and Hauri 1997.
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OIB Diversity

• Lavas of the Honolulu series formed in the
  presence of residual amphibole phlogopite

• Both phases are temperature sensitive and cannot
  have a plume origin.

• These lavas are best accounted for by the mixing
  of an upwelling plume with oceanic lithospheric
  mantle.

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Review

• OIB are the product of mixing of enriched mantle
  components and lower mantle depleted FOZO.
• Recycling of subducted slab is supported as it
  accounts for correlations between Os and O.
• Localised OIB heterogeneity can be accounted for
  by mixing of the plume source with upper mantle
  components.

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References

• Class, C., Goldstein, S.L. Plume lithosphere
  interactions in the ocean basins constraints
  from the source mineralogy. Earth and Planetary
  Sci. Lett. 150 (1997) 245-260.
• Garcia, M.O., Ito, E., Eiler, J.M., Pietruszka.
  Cruatal contamination of Kilauea Volcano magmas
  revealed by oxygen Isotope analyses of Glass and
  Olivine from Puu Oo eruption Lavas. Journal of
  Petrology 1998 vol. 39 no.5 p.803-817.
• Hofmann, A.W. Mantle Geochemistry the message
  from oceanic volcanism. Nature vol. 385 (1997)
  p.219-229.
• Lassiter, J.C., Hauri, E.H. Osmium-isotope
  variations in Hawaiian lavas evidence for
  recycled oceanic lithosphere in the Hawaiian
  plume. Earth and Planetary Sci. Lett. 164 (1998)
  p.483-496
• Pearson, D.G., R.W. Carlson, R.W., Shirley S.B.,
  Boyd, F.R., Nixon P.H. Stabilisation of Archean
  Lithospheric mantle A Re-Os study of peridotite
  xenoliths from the Kaapvaal Craton. Earth and
  Planetary Sci. Lett. 134. (1995) p.341-357
• Van Keken, P.E., Hauri, E.H., Ballentine, C.J.
  Mantle Mixing The generation, preservation, and
  destruction of chemical heterogeneity. Annu.
  Rev. Earth Planet. Sci. (2002), 30 p.493-525.