Which index proved to be useful to assess the dominating type of clay mineral in soil proposed by Martin and Russell

Solution (By Examveda Team)

Y-index is proved to be useful to assess the dominating type of clay mineral in soil proposed by Martin and Russell.
An index is defined as a numerical value describing the relative status of a population on a graduated scale with definite upper and lower limits, which permits and facilitates comparison with other groups classified by the same criteria & method.