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Rare earths in hawaiian basalts
Science (New York, N.Y.)
|August 19, 1966
Summary
Rare-earth element patterns in Hawaiian basalts reveal distinct groupings, suggesting fractional crystallization as the primary process altering their abundance. This analysis aids in understanding volcanic rock evolution.
Area of Science:
- Geochemistry
- Petrology
- Isotope geochemistry
Background:
- Hawaiian Islands represent a key oceanic hotspot volcanic province.
- Understanding trace element variations in basalts is crucial for deciphering mantle processes.
- Rare-earth elements (REEs) are sensitive indicators of magma evolution.
Purpose of the Study:
- To determine the concentrations of rare-earth elements in Hawaiian basalt samples.
- To investigate the relationship between REE abundance patterns and other geochemical/geophysical data.
- To infer the magmatic processes responsible for observed REE variations.
Main Methods:
- Neutron activation analysis (NAA) was employed to quantify REE concentrations.
- REE data were analyzed in conjunction with existing geological and geochemical datasets.
- Statistical and graphical methods were used to compare REE patterns.
Main Results:
- REE abundance patterns in the 20 analyzed basalts formed distinct, reproducible groups.
- These REE groupings closely correlated with classifications derived from other geological evidence.
- Specific REE patterns indicated significant variations in magma composition.
Conclusions:
- Fractional crystallization is strongly implied as the dominant mechanism controlling REE abundance in these Hawaiian basalts.
- The observed REE patterns support distinct evolutionary pathways for different basaltic magmas in the Hawaiian hotspot.
- This study provides insights into the magmatic plumbing system and mantle source characteristics of the Hawaiian Islands.
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