An interlocking spur is a natural geographical feature that occurs in the upper course of a river in which vertical erosion is the dominant force determining the river's course. As a river wanders between banks that are far apart, the promontories of the hills tend to jut out into the river valley resulting in a staggered formation, interlocked together somewhat like the teeth of a zip. These promontories are referred to as interlocking spurs.
If the river valley is subsequently subject to glaciation, the glacier shears off the tips of the interlocking spurs, due to its straighter course, creating truncated spurs.
While similar in general appearance, the mechanism behind the formation of interlocking spurs is different to that behind meanders, which arise out of a combination of horizontal erosion and deposition.
Famous quotes containing the word spur:
“We only seem to learn from Life that Life doesn’t matter so much as it seemed to do—it’s not so burningly important, after all, what happens. We crawl, like blinking sea-creatures, out of the Ocean onto a spur of rock, we creep over the promontory bewildered and dazzled and hurting ourselves, then we drop in the ocean on the other side: and the little transit doesn’t matter so much.”
—D.H. (David Herbert)