MODIFICATION OF THE LITHOSPHERIC MANTLE DURING THE EARLY ACTIVITY OF A CENOZOIC PLUME IN THE NORTH TIEN SHAN: EVIDENCE FROM MANTLE XENOLITHS IN BASALTS
Abstract and keywords
Abstract (English):
Data on the composition and the He-Ar and Sm-Nd isotopic systems of ultramafic xenoliths in Cretaceous-Paleogene basalt in the North Tien Shan provide insight into a lateral heterogeneity of the upper mantle. The mantle beneath the northern and southern portions of the North Tien Shan has a lherzolite composition, whereas pyroxenites found east of Lake Issyk Kul were produced by the partial melting of and metasomatism in the primary lherzolite mantle under the effect of a mantle plume at 55#xA0;Ma. This lateral heterogeneity of the upper mantle is clearly reflected in variations in the velocities of seismic waves and gravity anomalies when the influence of the crust is subtracted, as was determined for the portion of the Tien Shan east of the Talas-Fergana Fault.

Keywords:
Upper mantle, ultramafic xenoliths, basalts, mantle plume, North Tien Shan
Text
Publication text (PDF): Read Download
References

1. Bagdassarov, State of lithosphere beneath Tien Shan from petrology and electrical conductivity of xenoliths, // J. Geoph. Res., v. 116, 2011., doi:https://doi.org/10.1029/2009JB007125

2. Bazhenov, Paleomagnetism of Paleogene basalts from the Tien Shan, Kyrgyzstan: rigid Eurasia and dipole geomagnetic field, // Earth Planet. Sci. Lett., v. 195, 2002., doi:https://doi.org/10.1016/S0012-821X0100586-6

3. Bazhenov, Structural evolution of Central Asia to the North of Tibet: A synthesis of paleomagnetic and geological data, // Geotectonics, v. 38, 2004.

4. Bjarnason, Tomographic image of the Mid-Atlantic Plate boundary in South Western Iceland, // J. Geophys. Res., v. 98, 1993., doi:https://doi.org/10.1029/92JB02412

5. Charvis, Deep structure of the northern Kergulen Plateau and hotspot-related activity, // Geophys. J. Int.,, v. 122, 1995., doi:https://doi.org/10.1111/j.1365-246X.1995.tb06845.x

6. Chediya, Central Asia, noveishaya tektonika Severnoi Evrazii Neotectonics of North Eurasia, 1998.

7. Christensen, Compressional wave velocities in rocks at high temperature and pressures, critical thermal gradients, and crustal low-velocity zones, // J. Geophys. Res, v. 84, 1979., doi:https://doi.org/10.1029/JB084iB12p06849

8. Darbyshire, Crustal Structure above the Iceland Mantle Plume Imaged by ICEMELT Refraction Profile, // Geophys. J. Int., v. 135, 1998., doi:https://doi.org/10.1046/j.1365-246X.1998.00701.x

9. Dobretsov, Deep Inclusions in Basaltoids and Alkaline Gavvroids of Kazakhstan and North Tien Shan, Glubinnye vklyucheniya v kimberlitakh i problema sostava verkhnei mantii Deep Inclusions in Kimberlites and the Problem of the Upper Mantle Composition, 1974.

10. Dobretsov, Ultramafic inclusions in limburgites of North Tien Shan and the problem of upper mantle pyroxenites, Geol. Geofiz., v. 3, 1979.

11. Egorova, Mineral chemistry and thermobarometry of peridotite xenoliths from Central Tien Shan basalts, // Geophysical Research Abstracts, v. 11, 2009.

12. Ermolov, Petrology of analcime microdolerites and deep xenoliths in the Radchenko neck, // Geology of Kazakhstan, v. 3, 1997.

13. Gapeeva, Toyun Camptonites, South Tien Shan, Zap. Vses. Mineral. O-va, v. 78, no. 1, 1949.

14. Gapeeva, Toyun Bekinkinite, South Tien Shan, Zap. Vses. Mineral. O-va, v. 80, no. 1, 1951.

15. Gliko, On the Origin of Deep Processes Responsible for the Development of Intraplate Magmatism Areas and Continental Rifts, // Dokl. Akad. Nauk SSSR, v. 295, 1987.

16. Gliko, Thermal Model for Lithospheric Thinning and Associated Uplift in the Neotectonic Phase of Intraplate Orogenic Activity and Continental Rifts, // J. Geodyn.,, v. 3, 1985., doi:https://doi.org/10.1016/0264-37078590025-0

17. Grachev, Heterogeneity of the continental lherzolite mantle estimated from the ultrabasic xenoliths study, Physics and Interior Structure of the Earth in Russian, 1989.

18. Grachev, Early Cenozoic Magmatism and Geodynamics of North Tien Shan, // Physics of the Solid Earth, v. 35, 1999.

19. Grachev, Mantle plumes and problems of geodynamics, Physics of the Solid Earth, v. 36, 2000.

20. Grachev, Factors Responsible for the High Position of the Siberian Platform, // Physics of the Solid Earth, v. 42, 2006.

21. Ikorsky, Crushing technique of rocks and minerals in glass in a glass ampoule under the noble gases study, Abstracts of the 15 Symposium of isotope geochemistry, 1998.

22. Kamensky, Juvenile helium in ancient rocks: $^3$He excess in amphibolites from 2.8~Ga charnokite series -- crust mantle fluid in intracrustal magmatic processes, // Geochim. Cosmochim. Acta, v. 54, 1990., doi:https://doi.org/10.1016/0016-70379090127-7

23. Kaneoka, Noble gas signatures in the Earth's interior coupled or decoupled behavior among each isotope systematics and problems related to their implication // , Chem. Geol.,, v. 147, 1998., doi:https://doi.org/10.1016/S0009-25419700172-1

24. Kelemen, Origin of thick, high-velocity igneous crust along the U.S. Coast Margin, // J. Geophys. Res., v. 100, 1995., doi:https://doi.org/10.1029/95JB00924

25. Kosarev, Receiver functions for the Tien Shan analog broadband network: contrasts in the evolution of structures across the Talasso-Fergana fault, // J. Geophys. Res., v. 98, 1993., doi:https://doi.org/10.1029/92JB02651

26. Lal, Cosmic ray labeling of erosion surfaces: in situ nuclide production rates and erosion models, // Earth Planet. Sci. Lett., v. 104, 1991., doi:https://doi.org/10.1016/0012-821X9190220-C

27. Polyak, He, Ne, and Ar Isotope Composition of Underground Fluids in Tien Shan, // Geokhimiya, v. 1, 1989.

28. Polyak, Sub-Mantle Helium in South Tien Shan Fluids, Dokl. Akad. Nauk SSSR,, v. 312, 1990.

29. Radchenko, Diamond-bearing basaltoids in the Kastekskii Range, // Geology and Exploration in Kazakhstan, 1995.

30. Richard, $^143$Nd/$^144$Nd a natural tracer. An application to oceanic basalts, // Earth Planet. Sci. Lett., v. 31, 1976., doi:https://doi.org/10.1016/0012-821X7690219-3

31. Simonov, Cretaceous-Paleogene within-plate magmatism in Central Asia: data from the Tien Shan basalts, // Russian Geology and Geophysics, v. 49, 2008., doi:https://doi.org/10.1016/j.rgg.2008.06.009

32. Sobel, Cretaceous-Paleogene basaltic rocks of the Tuyon basin, NW China and the Kyrgyz Tian Shan: the trace of a small plume, Lithos, v. 50, 2000., doi:https://doi.org/10.1016/S0024-49379900046-8

33. Sobolev, Deep-Seated Inclusions and Problem of the Upper Mantle Composition, 1974.

34. Staudacher, Cosmogenic neon in ultramafic nodules from Asia and in quartzite from Antarctica, // Earth Plan. Sci. Lett., v. 106, 1991., doi:https://doi.org/10.1016/0012-821X9190065-P

35. Sun, Chemical composition and origin of the Earth's primitive mantle, // Geochim. Cosmochim. Acta, v. 46, 1982., doi:https://doi.org/10.1016/0016-70378290245-9

36. Thomas, A Paleomagnetic Study of Tertiary Formations From the Kyrgyz Tien-Shan and Its Tectonic Implications, J. Geophys. Res., v. 98, 1993., doi:https://doi.org/10.1029/92JB02912

37. Vinnik, Issledovaniya Mantii Zemli Seismicheskimi Metodami Seismic Studies of the Earth's Mantle, 1976.

38. Vinnik, S receiver functions and a new generation of mantle models, // Geoph. Res. Abstracts, v. 6, 2004.

39. Vinnik, Receiver function tomography of the central Tien Shan, // Earth Planet. Sci. Lett., v. 225, 2004.

40. Vinnik, Deep-Structure and Dynamics of the Tien Shan Lithosphere, // Dokl. Akad. Nauk SSSR, v. 268, 1998.

41. Wang, Yifen, The petrogenesis of Karakastek basanite in Kazakhstan, // Advances in Geosciences, v. 2, 1992.

42. Yakovlev, Crustal shortening during mountain building: A case study in the Pamir-Tien Shan and Altay-Mongolia region, // Russian J. Earth Sci., v. 3, 2001., doi:https://doi.org/10.2205/2001ES000072

43. Zheng, The lithospheric mantle beneath the southwestern Tienshan area, // Contrib. Mineral. Petrol., v. 151, 2006., doi:https://doi.org/10.1007/s00410-006-0071-x

44. Zindler, Chemical Geodynamics, // Ann. Rev. Earth Planet. Sci., v. 14, 1986., doi:https://doi.org/10.1146/annurev.ea.14.050186.002425

Login or Create
* Forgot password?