Circum-Arctic Lithosphere Evolution
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Samples from the Lomonosov Ridge place new constraints on the geological evolution of the Arctic Ocean
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Published:January 01, 2018
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CiteCitation
C. Knudsen, J. R. Hopper, P. R. Bierman, M. Bjerager, T. Funck, P. F. Green, J. R. Ineson, P. Japsen, C. Marcussen, S. C. Sherlock, T. B. Thomsen, 2018. "Samples from the Lomonosov Ridge place new constraints on the geological evolution of the Arctic Ocean", Circum-Arctic Lithosphere Evolution, V. Pease, B. Coakley
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Abstract
A number of rock samples were collected from two dredge positions on the Lomonosov Ridge at water depths of 2–3.5 km. The dredge samples are dominated by sediments deformed and metamorphosed under greenschist-facies conditions 470 myr ago according to 40Ar/39Ar dating of metamorphic muscovite. This shows that the Lomonosov Ridge was involved in a major Mid-Ordovician orogenic event that correlates with early arc–terrane accretion observed in northern Ellesmere Island, Svalbard, and other parts of the Caledonian belt. Detrital zircon age spectra of these metasediments span the Mesoproterozoic–Palaeoproterozoic with a main peak at around 1.6 Ga, and...
- absolute age
- alkaline earth metals
- Ar/Ar
- Arctic Ocean
- Arctic region
- arkosic composition
- Be-10
- beryllium
- composition
- concentration
- cooling
- EDS spectra
- electron microscopy data
- fission-track dating
- geochronology
- isotopes
- Lomonosov Ridge
- low temperature
- metals
- metamorphic rocks
- metasedimentary rocks
- ocean basins
- Ordovician
- orogeny
- paleogeography
- Paleozoic
- petrography
- provenance
- radioactive isotopes
- relative age
- samples
- sediments
- SEM data
- spectra
- temperature
- thermal history
- U/Pb
- X-ray spectra