1. Magmatism at Convergent Plate Margins. The wrong answer

2. Convergent Plate Margins

3. Two possible

4. Convergent Plate Margins: In Detail

5. Magmatism Calc-alkaline magmatism is characteristic. Variation diagrams against silica show fractionation Peacock index of 56-61 is calc-alkaline

6. Calc-Alkaline Trend Modern classification in an AFM diagram. Calc-Alkaline Trend no Fe-enrichment Tholeiite Trend Fe-enrichment

7. Calc-Alkaline Trend High water partial pressure lowers the solidus of olivine, px and plag. High water partial pressure raises the solidus of hornblende. High water partial pressure raises the oxygen fugacity and stabilises iron oxides.

8. Ocean Island Arcs & Cordillera Younger arcs are mainly tholeiitic, older and cordillera calc-alkaline

9. Ocean Island Arcs & Cordillera

10. Sub-groups of Calc-Alkaline Shoshonitic Depth of Benioff Zone

11. Distribution of Calc-Alkaline First magmas are mainly tholeiitic, followed by calc- alkaline and finally alkaline. K contents increase with the depth of the benioff zone.

12. Nature of Calc-Alkaline Volcanism

13. Petrology of Calc Alkaline Rocks.

14. Composition of Calc-Alkaline Large Ion Lithophiles (LILE) - high solubility in water High Field Strength Elements (HFSE) – not soluble in water Light Rare Earth Elements (LREE) - Heavy Rare Earth Elements (HREE) – retained in garnet

15. REE Calc-Alkaline Plag fractionation Tholeiite like Enriched

16. REE Calc-Alkaline Has similarities to kimberlites

17. Isotopes

18. B-Be Isotopes

19. Altered Oceanic Crust Black Smokers

20. Origins of Calc-Alkaline Magmas

21. From Where the Water? Dehydration at >600C and P >18 kbar

22. Origins of Calc-Alkaline Magmas Adding water to the overlying mantle wedge will cause it to melt

23. Where does the water go? Metasomatism

24. Cratons: Kimberlites

25. Melting of the Mantle Wedge

26. Rise and Fractionation