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Description

Metadata record for data from ASAC Project 400
See the link below for public details on this project.

Taken from one of the referenced papers:

Oceanic basalts are produced by melting of the Earth's mantle and are widely used to probe its composition. The observation of systematic, coupled variations in the neodymium, strontium and lead isotopic compositions of these basalts has been widely interpreted as reflecting the mixing of identifiable mantle components. White and Zindler and Hart have suggested that the isotopic compositions of mid-ocean-ridge and ocean island basalts (MORB and OIB) can be considered as mixtures of a depleted MORB-type mantle component with a few other components reflecting long-term enrichment of Rb/Sr, Nd/Sm and/or U/Pb ratios. It remains unclear whether these components should be considered as hypothetical mixing endmembers, or whether they exist physically as mantle reservoirs. This question may be addressed if the mixing endmembers of individual mantle plumes can be identified. To this end, we report linear Pb-Pb and curvilinear Pb-Nd and Pb-Sr isotopic covariations in Recent lavas of Heard Island, southern Indian Ocean, indicating binary mixing. The hyperbolic relationships are unique among oceanic basalts and tightly constrain the isotopic compositions of the plume source components, which do not coincide with the mantle endmember components of ref. 3. If our results are generally applicable to other plumes, they call into question the existence of large mantle reservoirs corresponding to these components, and indicate that actual oceanic basalt source reservoirs have intermediate isotopic compositions.

Quality

Values provided in temporal and spatial coverage are approximate only.

Access

A pdf copy of one of the referenced papers is available for download from the provided URL to AAD staff only.

Temporal Coverages

• Start date: 1986-09-30 - Stop date: 1995-03-31

Spatial Coverages

Science Keywords

• EARTH SCIENCE > SOLID EARTH > ROCKS/MINERALS/CRYSTALS > IGNEOUS ROCKS
• EARTH SCIENCE > SOLID EARTH > TECTONICS > VOLCANIC ACTIVITY > ERUPTION DYNAMICS

Use Constraints

This data set conforms to the CCBY Attribution License
(http://creativecommons.org/licenses/by/4.0/).

Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_400 when using these data.