Crystallization of Poikilo-macro-spherulitic Feldspar in a Rhum Peridotite

@article{Donaldson1973CrystallizationOP,
  title={Crystallization of Poikilo-macro-spherulitic Feldspar in a Rhum Peridotite},
  author={Colin H. Donaldson and Harald Irving Drever and Robert Johnston},
  journal={Nature},
  year={1973},
  volume={243},
  pages={69-70}
}
Here we define and describe a new macrocrystalline radiate texture in a major layered intrusion. This occurrence is inconsistent with the much applied adcumulus crystal growth hypothesis which dominates current thinking on the derivation of ultrabasic rocks from basaltic magmas. Some radical alternative mechanisms of origin are proposed. 
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References

SHOWING 1-5 OF 5 REFERENCES
The layered ultrabasic rocks of south-west Rhum, Inner Hebrides
  • W. Wadsworth
  • Biology
  • Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
  • 1961
TLDR
The present study was initiated in the Harris area, which covers the south-western part of the ultrabasic tract, because it was believed that the rocks exposed there represented a different level in the original intrusion, and that they would provide further evidence of the mode of formation. Expand
Metastable Growth Patterns in Some Terrestrial and Lunar Rocks
With reference to new information on the textures in some terrestrial mafic and ultramafic igneous rocks of Tertiary age, textural patterns attributable to metastable crystallization are described,Expand