To sink, swim, twin, or nucleate: A critical appraisal of crystal aggregation processes

Wieser, Penny, Vukmanovic, Zoja ORCID:, Kilian, Ruediger, Ringe, Emilie, Holness, Marian B., Maclennan, John and Edmonds, Marie (2019) To sink, swim, twin, or nucleate: A critical appraisal of crystal aggregation processes. Geology, 47 (10). 948–952. ISSN 0091-7613

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Crystal aggregates in igneous rocks have been variously ascribed to growth processes (e.g., twinning, heterogeneous nucleation, epitaxial growth, dendritic growth), or dynamical processes (e.g., synneusis, accumulation during settling). We tested these hypotheses by quantifying the relative orientation of adjacent crystals using electron backscatter diffraction. Both olivine aggregates from Kīlauea volcano (Hawaiʻi, USA) and chromite aggregates from the Bushveld Complex (South Africa) show diverse attachment geometries inconsistent with growth processes. Near-random attachments in chromite aggregates are consistent with accumulation by settling of individual crystals. Attachment geometries and prominent geochemical differences across grain boundaries in olivine aggregates are indicative of synneusis.

Item Type: Article
Faculty \ School: Faculty of Science > School of Environmental Sciences
UEA Research Groups: Faculty of Science > Research Groups > Geosciences
Depositing User: LivePure Connector
Date Deposited: 16 Sep 2022 12:36
Last Modified: 07 Oct 2023 01:15
DOI: 10.1130/g46660.1


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