Project Details
Projekt
The role of mantle plumes in the formation of Large Igneous Provinces: con-straints from noble gases
Applicant
Dr. Nicole Stroncik
Subject Area
Mineralogy, Petrology and Geochemistry
Term
from 2008 to 2011
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 79255487
Large igneous provinces (LIPs) are thought to have formed by magmatism resulting from decompressional melting of plume heads. Mantle plumes are upwellings of mantle material in focused conduits considered to originate from deep within the mantle. Plume heads are the leading ends of such upwellings. However, the evidence for this theory of LIP formation is mixed and has been challenged lately. In this context noble gas isotopes are important as a discriminator of deep-mantle origin because of the large and indicative isotope variations existing between the various terrestrial reservoirs. One of the main arguments for a plume origin of Continental Flood Basalt (CFB) magmas is excess 3He compared to MORB. High 3He/4He ratios have been found, e.g., in the Afar and Columbia River CFB provinces. Noble gas data from the Paraná-Etendeka LIP do not exist and the He isotope data available from the Tristan da Cunha hotspot are not meaningful. Thus we propose a noble gas study of samples from Tristan da Cunha, Etendeka and Paraná to constrain the mantle components involved in the formation of CFB and hotspot lavas and to shed some light on the role of plumes in LIP formation.
DFG Programme
Priority Programmes
International Connection
South Africa
Participating Persons
Professor Chris Harris, Ph.D.; Dr. Samuel Niedermann
