Size-graded layering in the Imilik gabbro, East Greenland
Summary Rhythmic layering in which the layers grade from coarse base to finer top is described in a plagioclase—pyroxene—olivine gabbro. The medium sizes of the various cumulus minerals at each level have significantly different settling velocities. Variation in the proportions of the cumulus minera...
| Published in: | Geological Magazine |
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| Main Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Cambridge University Press (CUP)
1971
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1017/s0016756800056661 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800056661 |
| Summary: | Summary Rhythmic layering in which the layers grade from coarse base to finer top is described in a plagioclase—pyroxene—olivine gabbro. The medium sizes of the various cumulus minerals at each level have significantly different settling velocities. Variation in the proportions of the cumulus minerals accompanies the size grading. It is shown that these characteristics can reasonably be accounted for if hydrodynamic factors exerted the main control, over-riding any chemical effects. |
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