A Study on Heavy Mineral Sands of Gopalpur Beach, Orissa

Mechanical disintegration of source rocks and selective transport of resulting particles together generate log normally distributed traction, saltation, and suspension sand sub-populations of heavy minerals, ilmenite, zircon, rutile and sillimanite as for quartz. Plots of cumulative weight per cent frequencies in geometric size grades of these heavy mineral sand populations against an arithmetic size grade scale (mm. grade scale with equal class interval) on an arithmetic probability paper gives rise to a more sharply segmented curve than a plot of these frequencies against ∅ scale and hence may be more effective in environmental discrimination. Wadell's shape factor is shown to give satisfactory results in the estimation of equivalent hydraulic sizes of the above heavy minerals from the associated quartz sands in a saltation population. The reported hydraulic inequrvalcncy observed in the case of coarser sand grades of heavy minerals with respect to those of quartz is explained to be due to restricted availability of these sizes rather than to differenual entrainment.