We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
U–Pb Dating, Oxygen and Hafnium Isotope Ratios of Zircon from Rocks of Oceanic Core Complexes at the Mid-Atlantic Ridge: Evidence for the Interaction of Contemporary and Ancient Crusts in the Spreading Center of the Ocean Floor.
- Authors
Bortnikov, N. S.; Silantyev, S. A.; Bea, F.; Montero, P.; Zinger, T. F.; Skolotnev, S. G.; Sharkov, E. V.
- Abstract
The U–Pb age and oxygen and hafnium isotope ratios of zircon from rocks of oceanic core complexes along the Mid-Atlantic Ridge have been studied using SHRIMP and MC-LA-ICP-MS techniques. The U–Pb dating revealed four groups of zircon: (1) 0.6–1.7 Ma, (2) 6.7–11.2 Ma, (3) 12.9–17.6 Ma, and (4) ≥ 200 to 2044 Ma. The δ18O values range from 4.74 to 7.2‰ and are distinct for zircon grains of different ages. The hafnium isotope ratio for zircon with an age from 0.6 to 17.6 Ma corresponds or is close to that of the MORB from the Central Atlantic. The oxygen and hafnium isotope compositions of zircon older than 280 Ma correspond to those of the sialic continental crust. The hypothesis of involvement of the ancient "pre-Atlantic" sialic (≥280 Ma) and "old Atlantic" (7–17 Ma) crusts in the generation of the contemporary ("juvenile") oceanic crust during the formation of the slow-spreading Mid-Atlantic Ridge has been proposed.
- Subjects
MID-Atlantic Ridge; HAFNIUM isotopes; SEA-floor spreading; OXYGEN isotopes; ZIRCON; OCEANIC crust
- Publication
Doklady Earth Sciences, 2019, Vol 489, Issue 2, p1396
- ISSN
1028-334X
- Publication type
Article
- DOI
10.1134/S1028334X19120109