Geochemical and geochronological studies of polychronic zircons in igneous rocks from the Mid-Atlantic Ridge and some features of its structure
Abstract
Polychronic zircons in basite-ultrabasite igneous rocks from the Mid-Atlantic Ridge have been studied. A number of features distinguishing oceanic crust formation were discovered following the zircons’ age determination. It was found out, that along with young zircons, whose age is close to the time of Cenozoic basalt eruption, more ancient (xenogenic) zircons occur in the rocks. It was determined how young zircons differ from ancient ones in their morphological features, internal structure, crystallization temperature, and REE content. Discrete concentrations in zircon dating, coinciding in their manifestation time with tectonic-magmatic epochs in the adjacent continents were identified. In accordance with the geological data, it appears that the present crust in the Atlantic Ocean represents a basement composed of Archean-Paleozoic basite-ultrabasite dislocated and metamorphosed rocks along with Pleistocene-Holocene unmetamorphosed effusive and sedimentary rocks.
About the Authors
O. G. Shulyatin
All-Russian Research Institute of Geology and Mineral Resources of the World Ocean named after Igor Gramberg (VNIIOkeangeologia named after I. S. Gramberg)
Russian Federation
Russian Federation
Candidate of Geological and Mineralogical Sciences, Leading Researcher
B. V. Belyatsky
A. P. Karpinsky Russian Geological Research Institute (VSEGEI)
Russian Federation
Russian Federation
Leading Engineer
A. A. Kremenetsky
Institute of Mineralogy, Geochemistry and Crystal Chemistry of Rare Elements (IMGRE)
Russian Federation
Russian Federation
Doctor of Geological and Mineralogical Sciences, Adviser General Director
References
1. Blyuman B. A. Zemnaya kora okeanov [Earth’s crust]. St. Petersburg: VSEGEI. 2011. Pp. 1–344.
2. Blyuman B. A. Aktualnye voprosy geologii okeanov i geologii kontinentov [Topical issues of the geology of the oceans and the geology of the continents]. St. Petersburg: VSEGEI. 2013. Pp. 1–399.
3. Bortnikov N. S., Sharkov E. V., Bogatikov O. A., Zinger T. F., Lepekhina E. N., Antonov A. V., Sergeev S. A. Discoveries of young and ancient zircons in gabbroids of the Markov depression, Mid-Atlantic Ridge, 5°30.6ʹ–5°32.4ʹ N (results of SHRIMP II U-Pb dating): importance for understanding the deep geodynamics of modern oceans). Doklady RAN. 2008. Vol. 421. No 3, pp. 240–248. (In Russian).
4. Zhirnov A. M. Severnyj trekhluchevoj nepodvizhnyj megakontinent Zemli: otkrytie veka [Northern three-beam stationary megacontinent of the Earth: the discovery of the century]. 2016. Pp. 1–183.
5. Zinger T. F., Bortnikov N. S., Sharkov E. V., Borisovskiy S. E ., Antonov A. V. The effect of plastic deformations in zircons on their chemical composition: using the example of gabbroids from the spreading zone of the Mid-Atlantic Ridge, Markov Basin, 6° N. Doklady RAN. 2010. Vol. 433. No 6,
6. pp. 785–791. (In Russian).
7. Koronovskij N. V., Milanovskij E. E. Orogennyj vulkanizm i tektonika Al’pijskogo poyasa Evrazii [Orogenic volcanism and tectonics of the Alpine belt of Eurasia]. Moscow: Nedra. 1973. 280 p.
8. Kosticyn Yu. A., Belousova E. A., Bortnikov N. S., Sharkov E. V. Zircons of gabbroids from the axial zone of the Mid-Atlantic Ridge: U-Pb age and 176Hf / 177Hf ratio (results of research using laser ablation). Doklady RAN. 2009. Vol. 428. No 5, pp. 654–658. (In Russian).
9. Kosticyn Yu. A., Belousova E. A., Silantev S. A., Bortnikov N. S., Anosova M. O. Current problems of geochemical and U-Pb geochronological studies of zircon in oceanic rocks. Geohimiya. 2015. No 9, pp. 771–800. (In Russian).
10. Krasnobaev A. A., Anfilogov V. N. Zircons and the problem of dunite origin. Doklady RAN. 2014. Vol. 456, pp. 310–313. (In Russian).
11. Kremenetsky A. A., Gromalova N. A. Nature of ancient zircons from the rocks of the Mid-Atlantic Ridge and Mendeleev Rising in the Arctic Ocean. Basic research. 2013. No 10, pp. 594–600. (In Russian).
12. Kremenetsky A. A., Gromalova N. A., Skolotnev S. G., Shulyatin O. G., Belousova E. A. Sources of matter of igneous rocks of the deep-sea bed of the Arctic Ocean and Central Atlantic according to U-Pb age, hafnium isotopy, and the geochemistry of REE zircons. Doklady RAN. 2017. Vol. 481. No 1, pp. 852–856. (In Russian).
13. Peyve A. V. Tectonics of the Mid-Atlantic Ridge. Geotektonika. 1975. No 5, pp. 3–17. (In Russian).
14. Petrova V. V., Skolotnev S. G., Chistyakova N. I. Features of the accessory zircon from the tufts of Mount Carter (Sierra Leone uplift, East Atlantic). Doklady RAN. 2010. Vol. 431. No 1, pp. 67–71. (In Russian).
15. Pogrebickiy Yu. E., Truhalev A. I. The origin of the deep basite-hyperbasite rocks is a key problem of the geology of the Mid-Atlantic Ridge. Russian Arctic: geology, history, mineralogy, geoecology. St. Petersburg: VNIIOkeangeologiya. 2002. Pp. 49–62. (In Russian).
16. Saveleva G. N., Batanova V. G., Berezhnaya N. G., Presnyakov S. L., Sobolev A. V., Skublov S. G., Belousov I. A. Polychronic formation of mantle complexes in ophiolites. Geotektonika. 2013. Vol. 47. No 3, pp. 43–57. (In Russian).
17. Silantev S. A., Kepke Y., Ariskin A. A., Anosova M. O., Krasnova E. A., Dubinina E.O., Zur G. The geochemical nature and age of the plagiogranite/gabbronorite association in the oceanic plutonic complex of the Mid-Atlantic Ridge in the region of 5°10ʹS. Petrologiya. 2014. Vol. 22. No 2, pp. 126–146. (In Russian).
18. Skolotnev S. G., Beltenev V. E., Lepekhina E. N., Ipateva I. S. Young and ancient zircons from the rocks of the oceanic lithosphere of the Central Atlantic, geotectonic consequences. Geotektonika. 2010. No 6, pp. 24–59. (In Russian).
19. Truhalev A. I., Silantev S. A., Kurencova N. A., Odinokov Yu. Yu., Udincev G. B., Kolosov O. I., Fedorov I. P., Lennikov A. M., Vasileva I. M., Drubeckoy E. R. The ancient K-Ar age of metagabbro and granitegneiss, dredged in the axial part of the Mid-Atlantic Ridge, 26° N. DAN SSSR. 1990. Vol. 311. No 6, pp. 1447–1452. (In Russian).
20. Sharkov E. V., Bortnikov N. S., Bogatikov O. A., Belyatsky B. V., Zinger T. F., Skolotnev S. G. Mesozoic zircon from gabbroids of the axial zone of the Mid-Atlantic Ridge, 6° N. Doklady RAN. 2004. Vol. 396. No 5, pp. 675–679. (In Russian).
21. Sharkov E. V., Bortnikov N. S., Bogatikov O. A., Zinger T. F., Beltenev V. E., Chistyakov A. V. The third layer of oceanic crust in the axial zone of the Mid-Atlantic Ridge (segment of Sierra Leone MAR, 6° N). Petrologiya. 2005. Vol. 13. No 6, pp. 592–625. (In Russian).
22. Shulyatin O. G., Andreev S. I., Belyatsky B. V., Truhalev A. I. Structural-tectonic position and age of plutonic mafic-ultramafic complexes of the MAR. VNIIOkeangeologiya. St. Petersburg. 2008. Pp. 392–408. (In Russian).
23. Shulyatin O. G., Andreev S. I., Belyatsky B. V., Truhalev A. I. Age and stages of formation of igneous rocks of the Mid-Atlantic Ridge according to geological and radiological data. Region. geologiya i metallogeniya. 2012. No 50, pp. 28–36. (In Russian).
24. Aumby, M. P. et al. 1992: Paleontological evidence for early exposure of deep oceanic crust on the Vema Fracture Zone Southern Wall (Atlantic Ocean, 10°45’). Mar. Geology. 107. 1/2. 1–7.
25. Bea, F., Fershtater, G. B., Montero, P., Whitehouse, M., Levin, V. Ya., Scarrow, J. H., Austrheim, H., Pushkarev, E. V. 2001: Recycling of continental crust into the mantle as revealed by Kytlym dunite zircons, Ural Mts, Russia. Terra Nova. 13. 407–412.
26. Bindeman, I., Gurenko, A., Carley, T., Miller, C., Martin, E., Sigmarsson, O. 2012: Silisic magma petrogenesis in Iceland by remelting of hydrothermally altered crust based on oxygen isotope diversity and disequilibria between zircon and magma with implications for MORB. Terra Nova. 24. 227–232.
27. Cherniak, D. J. 2010: Diffusion in accessory minerals: zircon, titanite, apatite, monazite and xenotime. Reviews in Mineralogy & Geochemistry. 72. 827–869.
28. Dosso, L., Bougault, H., Langmuir, C. et al. 1999: The age and distribution of mantle heterogeneity along the Mid-Atlantic Ridge (31°–41°N). Earth Planet. Sci. Lett. 170. 269–286.
29. Froitzheim, N., Rubatto, D. 1998: Continental breakup by detachment faulting: field evidence and geochronological constraints (Tasna nappe, Switzerland). Terra Nova. 10. 171–176.
30. Gardien, V., Paquette, J. L. 2004: Ion microprobe and ID-TIMS U-Pb dating on zircon grains from leg 173 amphibolites: evidence for Permian magmatism on the West Iberian margin. Terra Nova. 16. 226–231.
31. Grimes, C. B., John, B. E., Cheadle, M. J., Mazdab, F. K., Wooden, J. L., Swapp, S., Schwartz, J. J. 2009:
32. On the occurrence, trace element geochemistry, and crystallization history of zircon from in situ ocean lithosphere. Contrib. Mineral. Petrol. 158. 757–783.
33. Lagabrielle, Y., Bodinier, J. -L. 2008: Submarine reworking of exhumed subcontinental mantle rocks: field evidence from the Lherz peridotites, French Pyrenees. Terra Nova. 20. 11–21.
34. Melson, W. G., Hart, S. R., Thompson, G. 1972: St. Paul’s rocks, equatorial Atlantic: petrogenesis, radiometric ages and implications on sea-floor spreading. Memor. Geol. Soc. Amer. 132. 241–272.
35. Michael, P. J., Cheadle, M. 2009: Making a crust. Science. 323. 1017–1018.
36. Muntener, O., Pettke, Th., Desmurs, L., Meier, M., Schaltegger, U. 2004: Refertilization of mantle peridotite in embryonic ocean basins: trace element and Nd isotopic evidence and implications for crust-mantle relationships. Earth Planet. Sci. Lett. 221. 293–308.
37. O’Reilly, S. Y., Zhang, M., Griffin, W. L., Begg, G., Hronsky, J. 2009: Ultradeep continental roots and their oceanic remnants: a solution to the geochemical “mantle reservoir” problem? Lithos. 211. 1043–1054.
38. Pilot, J., Werner, C. D., Haubrich, F., Baumann, N. 1998: Paleozoic and Proterpozoic zircons from the Mid-Atlantic Ridge. Nature. 393. 676–679.
39. Puga, E., Fnning, C. M., Nieto, J. M., Federico, A. D. 2005: Recrystallization textures in zircon generated by oceanfloor and eclogite-facies metamorphism: a cathodoluminescence and U-Pb SHRIMP study, with constraints from REE elements. The Canadian Mineralogist. 43. 183–202.
40. Rudge, J. F. 2006: Mantle pseudo-isochrons revisited. Earth Planet. Sci. Lett. 249. 494–513.
41. Schmitt, A. K., Perfit, M. R., Rubin, K. H., Stockli, D. F., Smith, M. C., Cotsonika, L. A., Zellmer, G. F.,
42. Ridley, W. I., Lovera, O. M. 2011: Rapid cooling rates at an active mid-ocean ridge from zircon thermochronology. Earth Planet. Sci. Lett. 302. 349–358.
43. Schulz, B., Klemd, R., Bratz, H. 2006: Host rock compositional controls on zircon trace element signatures in metabasites from the Australpine basement. Geochim. Cosmochim. Acta. 70. 697–710.
44. Sharkov, E. V. 2012: Cyclic development of axial parts of slow-spreading ridges: evidence from Sierra Leone area, the Mid-Atlantic Ridge, 5–7°N. Tectonics – recent advances. 3–36.
Review
For citations:
Shulyatin O.G., Belyatsky B.V., Kremenetsky A.A. Geochemical and geochronological studies of polychronic zircons in igneous rocks from the Mid-Atlantic Ridge and some features of its structure. Regional Geology and Metallogeny. 2019;(77):11–19. (In Russ.)
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