Work

A dendritic growth mechanism for producing oscillatory zoning in igneous zircon

Year: 2024

Type: article

Abstract: The concentric oscillatory zoning pattern of igneous zircon is generally interpreted as evidence for core to rim growth during magmatic crystallization. This interpretation anchors a wide variety of qualitative and quantitative studies of zircon age, chemistry, and texture. We show, via detailed trace element mapping, that euhedral magmatic zircon with apparently typical cathodoluminescence oscillatory zoning instead displays evidence of dendritic growth. This observation challenges the unique interpretation of oscillatory zoning in zircon. Dendritic growth occurs under conditions of substantial undercooling, resulting in disequilibrium trace element concentrations in the zircon. Geochronological and geochemical analyses of zircon with this type of growth history require a different interpretative framework, with implications for time scales of magmatic and volcanic systems.

Source: Geology

DOI: 10.1130/g52641.1

Authors: Jack Gillespie, Benjamin Z. Klein, Jo Moore, Othmar Müntener, Lukas P. Baumgartner

Institutions: University of Lausanne, Freie Universität Berlin

Language: English

Topic: Geological and Geochemical Analysis

Subfield: Geophysics

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: hybrid

Funders: National Science Foundation, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung

Awards: Growth models for igneous and and metamorphic minerals: quartz and garnet, A novel perspective on the composition and evolution of the early continental crust from combined Lu-Hf and Sr isotopes in apatite