(redirected from xenocrysts)
Also found in: Encyclopedia.
Related to xenocrysts: xenolithic


 (zĕn′ə-krĭst′, zē′nə-)
A crystal foreign to the igneous rock in which it occurs.

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Geological Science) a crystal included within an igneous rock as the magma cooled but not formed from it
[C20: from xeno- + cryst(al)]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
This suggests that some of the phenocrysts that had formed in the rhyolitic magmas were later enclosed (as xenocrysts) within the more mafic one (i.e., as enclaves).
Xenocrysts are composed of orthoclase and reach 2-3 cm in size.
Lavas from the northwestern knoll are fresh, slightly ollvine-phyric lavas with abundant vesicles and rare, partially resorbed plagioclase xenocrysts. The 1970 sample from the northwestern knoll is transitional basalt, plotting on the Hawaiian tholeiite-alkalic basalt boundary, whereas the 1994 lava is tholeiitic basalt with a higher Si[O.sub.2] content (Fig.
Albite and alkali feldspar are absent in the groundmass in which the only feldspar is plagioclase in the andesine-labradorite range, indicating that the megacrysts are xenocrysts rather than phenocrysts.
Unit D is a relatively fresh, mostly dense but locally scoriaceous, porphyritic trachyandesite with ten to fifteen percent large plagioclase xenocrysts and phenocrysts.
Pellet-rich tuffistic (volcaniclastic) serpentine kimberlite breccia occupies the southern fissure appendage of the pipe which is extremely rich in mantle xenocrysts, megacrysts and xenoliths.
Shimizu, K., Nakamura, E., Kobayashi, K., and Maruyama, S., 2004, Discovery of Archean continental and mantle fragments inferred from xenocrysts in komatiites, the Belingwe greenstone belt, Zimbabwe: Geology, v.
We consider the first interpretation to be the best explanation for the Brazil Lake tantalite U-Pb results because tantalite is generally quite rare in crustal rocks and it seems remote that there would be tantalite xenocrysts originally present in the Brazil Lake magma.