Morphology unit | Altitude (m) | Average gradient (Degree) | Formation of protrusions | considerations |
Mountain | 1800 | 30 - 50 | Karaj Formation (tuff, …) | It seen in the mountains north of Tehran |
Hill | 1500 | 20 - 30 (hill) 30 - 40 (foot) | A & B Formation | Height of Saadat Abad, Tarasht & Abas abad. |
Old Fan | 1000 - 1500 | 5 - 10 | C Formation | Plain of Evin, Tajrish, Niavaran, … |
Young Fan | 1100 - 1400 | less than5 | D Formation (Coarse-grained) | Stream, old and new river routes |
Plain | 1000 - 1100 | Smooth | D Formation (Fine-grained) | South of Tehran |