1 / 18

Origin of the Late Miocene-Pliocene alkali mafic magmas in the western

Origin of the Late Miocene-Pliocene alkali mafic magmas in the western Pannonian Basin - inferences from compositions of olivine and spinel. Tamás Sági. Department of Petrology and Geochemistry, Eötvös University, Budapest, Hungary. Eötvös József Collegium, Budapest, Hungary.

martin-spears
Download Presentation

Origin of the Late Miocene-Pliocene alkali mafic magmas in the western

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Origin of the Late Miocene-Pliocene alkali mafic magmas in the western Pannonian Basin - inferences from compositions of olivine and spinel Tamás Sági Department of Petrology and Geochemistry, Eötvös University, Budapest, Hungary Eötvös József Collegium, Budapest, Hungary

  2. Neogene to Quaternary volcanic fields in Europe (Piromallo et al. 2001) (Harangi et al. 2006, GS London Memoir)

  3. Neogene volcanism in the Pannonian Basin (Harangi, AGH, 2001)

  4. Is there a mantle plume beneath the Pannonian Basin? (Granet et al. 1995, EPSL, 136 Wilson & Patterson, 2001 GSA SP, 352)

  5. Observations that could support the plume theory in the investigated region: • High heat flow (>90 mW/m2) • High mantle temperature (approx. 1500oC) • Isotope composition of the basalts (EAR, i.e. HIMU/FOZO-like) (Goes et al. 2000, JGR, 105.)

  6. Excess temperature between MORB and plume (Niu, 2005)

  7. The studied alkaline basaltic volcanoes

  8. Investigation of olivine phenocrysts

  9. Chemical composition of analyzed olivine phenocrysts Pauliberg Ság-hill Steinberg Uzsa

  10. Spinel inclusions in olivines (After Arai, 1994) (After Kamenetsky et al., 2001)

  11. Way of estimation of olivine crystallization temperature Graphical method (After Roeder and Emslie, 1970)

  12. Way of estimation of olivine crystallization temperature What was the composition of the primary magma? Primary magma estimation after Herzberg & O’Hara (2002) Primary magma estimation after Putirka (2007)

  13. The mantle potential temperature With the previously numerical method we got the crystallization temperature of olivine. To get mantle potential temperature we have to add ΔTfus = F[ΔHfus / (Cp)] heat to crystallization temperature. ΔHfus = 128.3 kJ/mole; Cp = 192.4 J/mole·K (Putirka et al., 2007)

  14. Olivine thermometry Numerical way – results TPut THerz ∆TPut (TMorb≈ 1450 °C) ∆ THerz (TMorb ≈ 1400 °C) Pauliberg(°C) Steinberg (°C) Uzsa (°C) Ság-hill (°C) 1559 1520 1463 1454 1465 1492 1398 1392 100 70 10 0 65 90 0 0

  15. Relationshipswith the deep structure

  16. Reason of melt generation in the post-extensional stage Suction by the Pannonian Basin thin-spot & Mantle flow along LAB irregularities?

  17. Conclusions -At the marginal regions of the basin we got higher mantle potential temperatures. -However, these observations don’t show a mantle plume! -Variance in temperature data can arise from different rate and depth of partial melting. -Heterogenous mantle source, melting in the spinel-garnet and garnet stability field. -We suggest a new model for alkaline basaltic magma formation in the Pannonian basin.

  18. Thank you for your interest!

More Related