About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
The AAPG/Datapages Combined Publications Database
Journal of Sedimentary Research (SEPM)
Abstract
Student Operator Error in Determination of Roundness, Sphericity, and Grain size
Robert L. Folk
ABSTRACT
Operator error in the use of Powers roundness images has been studied. A logarithmic scale is proposed for the statistical analysis of roundness counts and determination of mean roundness and roundness standard deviation. Experimental error in determination of mean roundness from counts of fifty grains was ±0.35 roundness class, a relatively large value considering the small range of mean roundness encountered. Pebble sphericities were determined by the three-diameter method; operator error here was virtually negligible, amounting to only ±0.02 in a range of values from 0.41 to 0.85. Error in determination of phi median size and phi standard deviation by sieving were likewise exceedingly small, amounting to only ±0.02 in median diameter. This surprisingly small value for operator error is ascribed to the use of probability paper, as variation in determination of parameters was much greater when ordinary squared paper was used.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
Watermarked PDF Document: $14 | |
Open PDF Document: $24 |