Petrology of some oceanic island basalts: PRIMELT2.XLS software for primary magma calculation
- Creators
- Herzberg, C.
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Asimow, Paul D.
Abstract
PRIMELT2.XLS software is introduced for calculating primary magma composition and mantle potential temperature (TP) from an observed lava composition. It is an upgrade over a previous version in that it includes garnet peridotite melting and it detects complexities that can lead to overestimates in TP by >100°C. These are variations in source lithology, source volatile content, source oxidation state, and clinopyroxene fractionation. Nevertheless, application of PRIMELT2.XLS to lavas from a wide range of oceanic islands reveals no evidence that volatile-enrichment and source fertility are sufficient to produce them. All are associated with thermal anomalies, and this appears to be a prerequisite for their formation. For the ocean islands considered in this work, TP maxima are typically ~1450–1500°C in the Atlantic and 1500–1600°C in the Pacific, substantially greater than ~1350°C for ambient mantle. Lavas from the Galápagos Islands and Hawaii record in their geochemistry high TP maxima and large ranges in both TP and melt fraction over short horizontal distances, a result that is predicted by the mantle plume model.
Additional Information
© 2008 American Geophysical Union. Received: 10 April 2008; Revised: 2 July 2008; Accepted: 15 July 2008; Published: 18 September 2008. Kaj Hoernle and Mike Rhodes are thanked for discussions. We are grateful to John Longhi and Cin-Ty Lee for thoughtful reviews. P.D.A. is supported by the NSF through grant OCE-0550216. Auxiliary material for this article contains a Microsoft Excel workbook called PRIMELT2.XLS in which the primary magma calculations described in this paper are implemented. Additional file information is provided in the readme.txt. The primary magma calculations described in this paper are implemented in this Microsoft Excel workbook, PRIMELT2.XLS. Please note that this workbook uses Visual Basic for Applications (VBA) macros for several of the iterative calculations. As such, it is incompatible with Microsoft Office 2008 for Macintosh, which does not support VBA macros. There may be other incompatibility issues that we are not aware of, but it has been tested on Microsoft Windows XP 2002 using Microsoft Office 2004 and on MacOS 10.4 and 10.5 using Microsoft Office 2004. A user guide is provided in Appendix A2 on implementation of PRIMELT2.XLS.Attached Files
Published - HERggg08.pdf
Supplemental Material - HERggg08readme.txt
Supplemental Material - HERggg08software.xls
Supplemental Material - HERggg08userguide.txt
Files
Additional details
- Eprint ID
- 12012
- Resolver ID
- CaltechAUTHORS:HERggg08
- OCE-0550216
- National Science Foundation
- Created
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2008-10-18Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences