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
- Авторлар: Bortnikov N.1, Silantyev S.2, Bea F.3, Montero P.3, Zinger T.4, Skolotnev S.5, Sharkov E.1
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Мекемелер:
- Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences
- Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences
- Department of Mineralogy and Petrology, University of Granada (Spain), Campus Fuentenueva, Departamento de Mineralogia y Petrologia
- Institute of Precambrian Geology and Geochronology, Russian Academy of Sciences
- Geological Institute, Russian Academy of Sciences
- Шығарылым: Том 489, № 2 (2019)
- Беттер: 1396-1401
- Бөлім: Geology
- URL: https://journals.rcsi.science/1028-334X/article/view/195680
- DOI: https://doi.org/10.1134/S1028334X19120109
- ID: 195680
Дәйексөз келтіру
Аннотация
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.
Авторлар туралы
N. Bortnikov
Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences
Email: silantyev@geokhi.ru
Ресей, Moscow, 119017
S. Silantyev
Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences
Хат алмасуға жауапты Автор.
Email: silantyev@geokhi.ru
Ресей, Moscow, 119991
F. Bea
Department of Mineralogy and Petrology, University of Granada (Spain), Campus Fuentenueva, Departamento de Mineralogia y Petrologia
Email: silantyev@geokhi.ru
Испания, Granada, 18002
P. Montero
Department of Mineralogy and Petrology, University of Granada (Spain), Campus Fuentenueva, Departamento de Mineralogia y Petrologia
Email: silantyev@geokhi.ru
Испания, Granada, 18002
T. Zinger
Institute of Precambrian Geology and Geochronology, Russian Academy of Sciences
Email: silantyev@geokhi.ru
Ресей, St. Petersburg, 199034
S. Skolotnev
Geological Institute, Russian Academy of Sciences
Email: silantyev@geokhi.ru
Ресей, Moscow, 119017
E. Sharkov
Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences
Email: silantyev@geokhi.ru
Ресей, Moscow, 119017