21. The study of extensional flows is called extensional rheology. 22. See for example extension, and the extensional devices. 23. Extensional basins occur in the central and east parts of the fold belt.24. Buchan metamorphism occurs often in extensional settings, for example at rift basins. 25. Ribbons are long and narrow extensional troughs that are separated by narrow ridges. 26. Extensional tectonics were also most active during the Famennian.27. This caused strong extensional stresses in the moon's crust leading to cracking. 28. The Rhine Graben is a major extensional basin. 29. Alba s tectonic features are almost entirely extensional , consisting of normal tension cracks. 30. Commercially available extensional rheometers have been segregated according to their applicability to viscosity ranges.
