Full metadata
Title
Boron isotopic composition of the subcontinental lithospheric mantle
Description
Boron concentrations and isotopic composition of phlogopite mica, amphibole, and selected coexisting anhydrous phases in mantle-derived xenoliths from the Kaapvaal Craton were measured by secondary ion mass spectrometry in an effort to better understand the B isotope geochemistry of the subcontinental lithospheric mantle (SCLM) and its implications for the global geochemical cycle of B in the mantle. These samples display a wide, and previously unrecognized, range in their boron contents and isotopic compositions reflecting a complex history involving melt depletion and metasomatism by subduction- and plume-derived components, as well as late stage isotopic exchange related to kimberlite emplacements. Micas from ancient lithospheric harzburgite metasomatized by slab-derived fluids suggest extensive B-depletion during subduction, resulting in low-B, isotopically light compositions whereas kimberlite-related metasomatic products and a sample from the 2 Ga Palabora carbonatite have boron isotopic compositions similar to proposed primitive mantle. The results suggest that subduction of oceanic lithosphere plays a limited role in the B geochemistry of the convecting mantle.
Date Created
2014
Contributors
- Guild, Meghan R (Author)
- Hervig, Richard L (Thesis advisor)
- Bell, David R. (Committee member)
- Mcnamara, Allen (Committee member)
- Arizona State University (Publisher)
Topical Subject
Resource Type
Extent
vi, 62 p. : col. ill
Language
eng
Copyright Statement
In Copyright
Primary Member of
Peer-reviewed
No
Open Access
No
Handle
https://hdl.handle.net/2286/R.I.25881
Statement of Responsibility
by Meghan R. Guild
Description Source
Retrieved on Nov. 24, 2014
Level of coding
full
Note
thesis
Partial requirement for: M.S., Arizona State University, 2014
bibliography
Includes bibliographical references (p. 46-53)
Field of study: Geological sciences
System Created
- 2014-10-01 05:01:42
System Modified
- 2021-08-30 01:33:03
- 3 years 2 months ago
Additional Formats