Isotopic evidence from the eastern Canadian shield for geochemical discontinuity in the Proterozoic mantle

Autor:	Joseph L. Wooden, L. D. Ashwal
Rok vydání:	1983
Předmět:	Basalt geography Anorthosite Multidisciplinary geography.geographical_feature_category Proterozoic Magmatism Geochemistry Mid-ocean ridge Massif Isotopes of strontium Mantle (geology) Geology
Zdroj:	Nature. 306:679-680
ISSN:	1476-4687 0028-0836
DOI:	10.1038/306679a0
Popis:	The Nd and Sr isotopic compositions presently reported for anorthosites and related rocks from the Grenville and Nain Provinces of the eastern Canadian shield indicate that the massifs were delivered from at least two distinct mantle source regions which were established before 1650 Myr ago. These regions were episodically involved in magmatism over about 500 Myr. One reservoir was isotopically similar to the depleted, modern midocean ridge basalt source. The other reservoir was chondritic-to-moderately-enriched, and is most easily identified in the Nain Province, but may have occurred scattered throughout Superior Province, as well.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::5a349b6201fd231114f58bdba015b939 https://doi.org/10.1038/306679a0 Zobrazit plný text záznamu