Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (12) Citing Articles via Google Scholar Google Scholar Articles by Feinberg, J. M. Articles by Scott, G. R. Search for Related Content GeoRef GeoRef Citation

Epitaxial relationships of clinopyroxene-hosted magnetite determined using electron backscatter diffraction (EBSD) technique

¹ Department of Earth and Planetary Science, University of California, Berkeley, California 94720, U.S.A.
² Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, California 94709, U.S.A

Crystallographic relationships between exsolved phases and their hosts are typically characterized using transmission electron microscopy (TEM) or single crystal X-ray diffraction (XRD). In this investigation, electron backscatter diffraction (EBSD) was used to determine the epitaxial relationships of exsolved laths of magnetite in clinopyroxenes from three sampling sites in the Cretaceous Messum Complex of Namibia. Two orientations of magnetite inclusions are found with their long axes subparallel to [100] and [001] of the host clinopyroxene. Inclusions subparallel to [100]_c have [10]_m //[010]_c, (1)_m //(01)_c, and [112]_m //[101]_c. Inclusions subparallel to [001]_c have [10]_m // [010]_c, (111)_m //(100)_c, and [2]_m //[001]_c. The EBSD-derived orientation relationships agree well with previous TEM and XRD studies on similar materials.

The crystallographic relationships obtained with EBSD are used in conjunction with optimal phase boundary theory to determine the exsolution temperature of the magnetite inclusions, which is of importance to paleomagnetic studies. For one sample, this temperature (840 ±50 °C) can be compared with that (865 ±25 °C) derived from a more widely used cation exchange geothermometer. Thus it appears clear that exsolution occurred well above the Curie temperature of pure magnetite (580 °C).

This article has been cited by other articles:

				J. A. Tarduno Geodynamo History Preserved in Single Silicate Crystals: Origins and Long-Term Mantle Control Elements, August 1, 2009; 5(4): 217 - 222. [Abstract] [Full Text] [PDF]

				J. M. Feinberg, G. R. Scott, P. R. Renne, and H.-R. Wenk Exsolved magnetite inclusions in silicates: Features determining their remanence behavior Geology, June 1, 2005; 33(6): 513 - 516. [Abstract] [Full Text] [PDF]

				S. A. Morse, S.A. Morse, and M. Ross Kiglapait mineralogy IV: The augite series American Mineralogist, October 1, 2004; 89(10): 1380 - 1395. [Abstract] [Full Text] [PDF]