Here are two examples of target variance:

1-Downstream variation in particle size is of great interest in predicting the viability of future gravel operations and the proportion of coarse gravel available from place to place in a river valley. This example shows the measured decline in median particle size of gravels beneath the Poudre River valley.

2-Stratigraphic variation is of interest in estimating a resource or planning mining operations. In the South Platte valley, gravel units vary in particle size. If the thickness and extent of units and the particle size are known, the quantity of product that can be produced from each layer can be estimated.

This page is <URL: https://pubsdata.usgs.gov/pubs/of/1998/ofr-98-0332/sld012.htm>
Site Maintainers: Randy Schumann and Gene Ellis
For more information about this report contact: David A. Lindsey
Last updated 07 Dec 2016