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Major and trace element compositions of georgiaites: clues to the source of North American tektites


Albin, EF and Norman, MD and Roden, MF, Major and trace element compositions of georgiaites: clues to the source of North American tektites, Meteoritics and Planetary Science, 35, (4) pp. 795-806. ISSN 0026-1114 (2000) [Refereed Article]

DOI: doi:10.1111/j.1945-5100.2000.tb01463.x


Electron microprobe and laser ablation, inductively-coupled plasma mass spectrometer analyses of 24 georgiaites show that these tektites are all Si-rich (79-83 wt% SiO 2 ) glasses with variable major and trace element abundances (e.g., FeO varies from 2.1 to 3.7 wt%). Glass compositions are similar to but not identical with average upper continental crust. For example, georgiaites are light rare earth element enriched with small negative Eu anomalies (Eu/Eu* = 0.73-0.86) and La-Th-Sc systematics are intermediate between that of Archean and post-Archean continental crust. When the georgiaite data are placed in the context of data for all North American tektites, triangular arrays appear on some oxide-oxide plots (e.g., FeO-MgO). Large variations in refractory element abundances and ratios compared to the variation in SiO 2 favors mixing over volatilization as a cause of the compositional variation. If all the tektites formed as a result of a single impact, then triangular arrays in oxide-oxide variation diagrams require at least three source components. These components include a Si-rich material, probably a quartz-rich sand that was predominant in the formation of georgiaites. Two relatively silica-poor and Fe-rich components have compositional characteristics similar to shales and greywackes. The La-Th-Sc systematics of the georgiaites and most other North American tektites are distinctive and could potentially be used to link the tektites to Eocene sediments at the Chesapeake Bay impact structure.

Item Details

Item Type:Refereed Article
Research Division:Earth Sciences
Research Group:Geochemistry
Research Field:Geochemistry not elsewhere classified
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the earth sciences
ID Code:20473
Year Published:2000
Web of Science® Times Cited:17
Deposited By:Centre for Ore Deposit Research - CODES CoE
Deposited On:2000-08-01
Last Modified:2011-11-21

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