Phosphorus zoning as a recorder of crystal growth kinetics

Autor(en)
I. Baziotis, P. D. Asimow, T. Ntaflos, J. W. Boyce, F. M. McCubbin, A. Koroneos, D. Perugini, S. Flude, M. Storey, Y. S. Liu, S. Klemme, J. Berndt
Abstrakt

Composite mantle xenoliths from the Cima Volcanic Field (CA, USA) contain glassy veins that cross-cut lithologic layering and preserve evidence of lithospheric melt infiltration events. Compositions and textures of minerals and glasses from these veins have the potential to place constraints on the rates and extents of reaction during infiltration. We studied glass-bearing regions of two previously undescribed composite xenoliths, including optical petrography and chemical analysis for major and trace elements by electron probe microanalysis and laser-ablation inductively coupled plasma mass spectrometry. The petrogenetic history of each vein involves melt intrusion, cooling accompanied by both wall-rock reaction and crystallization, quench of melt to a glass, and possibly later modifications. Exotic secondary olivine crystals in the veins display concentric phosphorus (P)-rich zoning, P-rich glass inclusions, and zoning of rapidly diffusing elements (e.g., Li) that we interpret as records of rapid disequilibrium events and cooling rates on the order of 10 °C/h. Nevertheless, thermodynamic modeling of the diversity of glass compositions recorded in one of the samples demonstrates extensive reaction with Mg-rich olivine from the matrix before final quench. Our results serve as a case study of methods for interpreting the rates and processes of lithospheric melt-rock reactions in many continental and oceanic environments.

Organisation(en)
Department für Lithosphärenforschung
Externe Organisation(en)
Agricultural University of Athens, California Institute of Technology (Caltech), National Aeronautics & Space Administration (NASA), Aristotle University of Thessaloniki, Università degli Studi di Perugia, Roskilde University, University of Edinburgh, Natural History Museum of Denmark, Universität Münster, China University of Geosciences
Journal
Contributions to Mineralogy and Petrology
Band
172
Anzahl der Seiten
32
ISSN
0010-7999
DOI
https://doi.org/10.1007/s00410-017-1376-7
Publikationsdatum
07-2017
Peer-reviewed
Ja
ÖFOS 2012
105105 Geochemie, 105120 Petrologie
Schlagwörter
ASJC Scopus Sachgebiete
Geochemistry and Petrology, Geophysics
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/260fe485-4bc7-46a1-9599-509ea9ae6cd6