RECOMMENDED LESSONS: Runoff Runoff is precipitation that did not get (infiltrated) absorbed into the soil, or did not evaporate, and therefore made its way from the ground surface into places that water collect. Runoff causes erosion, and also carry chemicals and substances on the ground surface along to the rivers where the water ends up.
Noun. 1. obelisk-a stone pillar having a rectangular cross section tapering towards a pyramidal top. pillar, column-a vertical cylindrical structure standing alone and not supporting anything (such as a monument).
The Egyptian obelisk is made out of stone, while the George Washington Monument is made out of Marble. The Obelisk of Theodosius stands today at 19.5 meters or 63.97638 feet, while the George Washington Monument stands at 555 feet 5 1/8 inches.