Thank you very much dr. Bayan for your carful answer , and I like to say that Iraqi basement rocks depth may reach to 15 km in some area of southern part of Iraq specially at the eastern part of it
In general we had better not discuss about the depth of crystallization because the crystallization begins from the mantle. As I understood you need to know the thickness of the continental crust in some parts of Iraq. It depends on the tectonic settings and the morphology of the area. The best method of measuring the thickness of continental crust is geophysical methods and the interpretation of Bouguer gravity anomalies.