Search: (FÖRF:(Stefan Claesson)) >
Reactive monazite a...
Reactive monazite and robust zircon growth in diatexitesand leucogranites from a hot, slowly cooled orogen : implicationsfor the Palaeoproterozoic tectonic evolution of the central Fennoscandian Shield, Sweden
-
- Högdahl, Karin (author)
- Uppsala universitet,Berggrundsgeologi
-
- Majka, Jaroslaw (author)
- Uppsala universitet,Berggrundsgeologi
-
- Sjöström, Håkan (author)
- Uppsala universitet,Berggrundsgeologi
-
show more...
-
- Persson Nilsson, Katarina (author)
- Geol Survey Sweden, S-75328 Uppsala, Sweden
-
- Claesson, Stefan (author)
- Swedish Museum Nat Hist, Lab Isotope Geol, S-10405 Stockholm, Sweden
-
- Konecny, Patrik (author)
- Geol Survey Slovak Republ, Bratislava 81704, Slovakia
-
show less...
-
(creator_code:org_t)
- 2011-07-24
- 2012
- English.
-
In: Contributions to Mineralogy and Petrology. - : Springer Science and Business Media LLC. - 0010-7999 .- 1432-0967. ; 163:1, s. 167-188
- Related links:
-
https://urn.kb.se/re...
-
show more...
-
https://doi.org/10.1...
-
show less...
Abstract
Subject headings
Close
- Monazite in melt-producing, poly-metamorphic terranes can grow, dissolve or reprecipitate at different stages during orogenic evolution particularly in hot, slowly cooling orogens such as the Svecofennian. Owing to the high heat flow in such orogens, small variations in pressure, temperature or deformation intensity may promote a mineral reaction. Monazite in diatexites and leucogranites from two Svecofennian domains yields older, coeval and younger U–Pb SIMS and EMP ages than zircon from the same rock. As zircon precipitated during the melt-bearing stage, its U–Pb ages reflect the timing of peak metamorphism, which is associated with partial melting and leucogranite formation. In one of the domains, the Granite and Diatexite Belt, zircon ages range between 1.87 and 1.86 Ga, whereas monazite yields two distinct double peaks at 1.87–1.86 and 1.82–1.80 Ga. The younger double peak is related to monazite growth or reprecipitation during subsolidus conditions associated with deformation along late-orogenic shear zones. Magmatic monazite in leucogranite records systematic variations in composition and age during growth that can be directly linked to Th/U ratios and preferential growth sites of zircon, reflecting the transition from melt to melt crystallisation of the magma. In the adjacent Ljusdal Domain, peak metamorphism in amphibolite facies occurred at 1.83–1.82 Ga as given by both zircon and monazite chronology. Pre-partial melting, 1.85 Ga contact metamorphic monazite is preserved, in spite of the high-grade overprint. By combining structural analysis, petrography and monazite and zircon geochronology, a metamorphic terrane boundary has been identified. It is concluded that the boundary formed by crustal shortening accommodated by major thrusting.
Subject headings
- NATURVETENSKAP -- Geovetenskap och miljövetenskap -- Geologi (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences -- Geology (hsv//eng)
Keyword
- Geochronology
- Monazite
- Zircon
- SIMS
- EMP
- Svecofennian
- Orogen
Publication and Content Type
- ref (subject category)
- art (subject category)
Find in a library
To the university's database