Tungsten-182 heterogeneity in modern ocean island basalts

TitleTungsten-182 heterogeneity in modern ocean island basalts
Publication TypeJournal Article
Year of Publication2017
AuthorsMundl A., Touboul M., Jackson MG, Day JMD, Kurz M.D, Lekic V., Helz R.T, Walker R.J
JournalScience
Volume356
Pagination66-+
Date Published2017/04
Type of ArticleArticle
ISBN Number0036-8075
Accession NumberWOS:000398689100038
Keywordsbase; core formation; earths mantle; hawaiian picrites; he-3/he-4 ratios; helium; Magma Ocean; origin; samoan lavas; tungsten isotopic composition
Abstract

New tungsten isotope data for modern ocean island basalts (OIB) from Hawaii, Samoa, and Iceland reveal variable W-182/W-184, ranging from that of the ambient upper mantle to ratios as much as 18 parts per million lower. The tungsten isotopic data negatively correlate with He-3/He-4. These data indicate that each OIB system accesses domains within Earth that formed within the first 60 million years of solar system history. Combined isotopic and chemical characteristics projected for these ancient domains indicate that they contain metal and are repositories of noble gases. We suggest that the most likely source candidates are mega-ultralow-velocity zones, which lie beneath Hawaii, Samoa, and Iceland but not beneath hot spots whose OIB yield normal W-182 and homogeneously low He-3/He-4.

DOI10.1126/science.aal4179
Student Publication: 
No