1. Geochemistry of Dominant Low-Ti Basalts of the Siberian Traps and
Subduction-Related Model of Their Origin
Ivanov A.V.
Institute of the Earth’s Crust,
Siberian Branch,
Russian Academy of Sciences
Flood basalt geochemistry
1.1. Columbia River & Siberian Traps
2. Subduction-related model
for flood basalts (Siberian Traps)

2. Columbia river
Os-isotope data are after Chesley and Ruiz (1998)

3. Columbia river
Data are plotted after Hooper and Hawkesworth (1993)

4. Columbia river
Data are plotted after Hooper and Hawkesworth (1993)

5. Columbia river

6. Columbia river
High-Mg basalts of
Klyuchevskoi volcano

7. Siberian Traps
Pangea

8. Siberian Traps
Ages are for ‘basalts’ only !

9. Siberian Traps
Approximate size of
the Columbia River
flood basalts

10. Siberian Traps
Noril’sk

11. Upper Morongovsky subsuite to
Siberian Traps
Upper Morongovsky subsuite to
Samoedsky suite basalts are not contaminated
Saddle Mountains
Imnaha
Data are plotted after Wooden et al. (1993)

12. Siberian Traps
Data are plotted after Wooden et al. (1993)

13. Siberian Traps

14. Siberian Traps

15. Siberian Traps
Subduction
signatures are more
prominent

16. Model
After Ohtani (2005)

17. Model
Based on Bina et al. (2001), Litasov and Ohtani (2003), Hirschmann et al. (2005)

18. Siberian Traps
2300 km
Transbaikalian belt
(Andean-type
orogen)

19. Model
Transbaikalian belt

20. Siberian Traps, Noril’sk event
Model
Siberian Traps, Noril’sk event

21. Siberian Traps, Tunguska event
Model
Siberian Traps, Tunguska event

22. Conclusions
1. Primitive mantle-derived flood basalts (with Siberian Traps and Columbia River as examples) show similarities with typical island-arc basalts. They are remarkably different with ocean island basalts.
2. Flood basalt origin can be explained by water-recycling through transition zone of mantle via stagnated (by depth) subduction.

23. Thanks!