Hollow apatites in a layered basic intrusion, Norway

Summary Cumulate apatite crystals with infilled tube-like cavities parallel to the c -axis are described from a layered gabbro intrusion in Northern Norway. These are considered to be skeletal crystals produced by rapid growth in the supercooled roof zone of the magma chamber. At least two stages of...

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Bibliographic Details
Published in:Geological Magazine
Main Author: Gardner, P. M.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1972
Subjects:
Online Access:http://dx.doi.org/10.1017/s0016756800039765
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800039765
Description
Summary:Summary Cumulate apatite crystals with infilled tube-like cavities parallel to the c -axis are described from a layered gabbro intrusion in Northern Norway. These are considered to be skeletal crystals produced by rapid growth in the supercooled roof zone of the magma chamber. At least two stages of growth are suggested on the basis of the morphology of the apatites. The interiors of the crystals contain phases representing the trapped magma or the cumulus mineral phase within which they are enclosed. Recirculation of the apatite primocrysts by convection currents is indicated by the interrupted form of some of the tubes.