Jump to main content
US EPA
United States Environmental Protection Agency
Search
Search
Main menu
Environmental Topics
Laws & Regulations
About EPA
Health & Environmental Research Online (HERO)
Contact Us
Print
Feedback
Export to File
Search:
This record has one attached file:
Add More Files
Attach File(s):
Display Name for File*:
Save
Citation
Tags
HERO ID
4839069
Reference Type
Journal Article
Title
Mo-98/Mo-95 and U-238/U-235 in lamproites, shoshonites, and high-K calc-alkaline rocks from Western Alps: inferences on their genesis
Author(s)
Casalini, M
Year
2018
Volume
137
Issue
3
Page Numbers
465-477
DOI
10.3301/IJG.2018.20
Web of Science Id
WOS:000440007900007
Abstract
Oligocene ultrapotassic and associated potassic rocks from Western Alps derived from the crystallisation of magmas originated from partial melting of mantle sources extremely enriched in recycled crustal components. These rocks are well suited for studying the effects of subduction-related, sediment-derived metasomatism on Molybdenum and Uranium isotopes. This paper reports the first Mo-98/Mo-95 and U-238/U-235 data on potassic and ultrapotassic rocks at destructive plate margins. Both Mo-98/Mo-95 and U-238/U-235 ratios show large variations in the samples from Western Alps. U isotope compositions are consistent with an increasing role of metasomatising melts from recycled sediments, which explains the variable enrichment in potassium and incompatible trace elements passing from high-K calc-alkaline to lamproitic magmas through shoshonitic ones. The variation of Mo isotope compositions is more complex due to the extreme depletion in Mo observed and since their values exceed the range observed for volcanic arcs. These features were investigated considering several possible processes such as secondary weathering, hosting of Mo related to residual mineral phases during sediment melting or physical removal during subduction. The results were also discussed in the framework of the complex processes responsible for the genesis and geochemical characteristics of the Tethyan Realm Lamproites, particularly in relationship with the exotic SALATHO geochemical component.
Keywords
Molybdenum isotopes; Uranium isotopes; Western Alps; lamproites; shoshonites
Tags
IRIS
•
Molybdenum
Litsearch 2018
WOS
•
Uranium
Uranium Literature Search Update 4/2020
WOS
•
Uranium Toxicological Review
Date limited literature search 2011-2021
WOS
New to this search
Exposure Criteria by Research Topic
Single measurements for estimation of ranking/effect of time
Home
Learn about HERO
Using HERO
Search HERO
Projects in HERO
Risk Assessment
Transparency & Integrity