Arcuate bands or waves, convex downglacier, that develop in an icefall. Alternating light and dark bands are called banded ogives or Forbes bands. Each pair of bands, that is, one crest (light) and on
e trough (dark), represents a year's movement through the icefall. It can be shown that, to yield visible banding, ice must flow through the icefall in a time shorter than the duration of the ablation season or accumulation season. James Forbes was the first to describe ogives, in 1843.
An oil is a substance that is in a viscous liquid statel (‘oily’) at ambient temperatures or slightly warmer, and is both hydrophobic (immiscible with water) and lipophilic (miscible with other oils,
literally). This generag definition includes compound classes with otherwise unrelated chemical structures, properties, and uses, including vegetable oils, resochemical oils, and volatile essential oils. Oil is a nonpolar substance. [Wikipedia]