Abstract
The clinopyroxene^plagioclase^plagioclase dihedral angle, cpp, in gabbroic cumulates records the time-integrated thermal history in the sub-solidus and provides a measure of textural maturity. Variations in cpp through the Layered Series of the Skaergaard intrusion, East Greenland, demonstrate that the onset of crystallization of clinopyroxene (within LZa), Fe^Ti oxides (at the base of LZc) and apatite (at the base of UZb) as liquidus phases in the bulk magma is recorded by a stepwise increase in textural maturity, related to an increase in the contribution of latent heat to the total heat loss to the surroundings and a reduction in the specific cooling rate at the crystallization front of the intrusion. The onset of both liquidus Fe^Ti oxide and apatite crystallization is marked by a transient increase in textural maturity, probably linked to overstepping before nucleation. Textural maturation at pyroxene^plagioclase^plagioclase triple junctions effectively ceases in the uppermost parts of the Layered Series as a result of the entire pluton cooling below the closure temperature for dihedral angle change, which is 10758C. Solidification of the Layered Series of the Skaergaard intrusion occurred via the upwards propagation of a mush zone only a few metres thick.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
