SPHERICITY AND ROUNDNESS OF QUARTZ GRAINS IN SEDIMENTS

Abstract

Research Article| September 01, 1955 SPHERICITY AND ROUNDNESS OF QUARTZ GRAINS IN SEDIMENTS J. R CURRAY; J. R CURRAY SCRIPPS INSTITUTE OF OCEANOGRAPHY, LA JOLLA, CALIF.; PENNSYLVANIA STATE UNIVERSITY, UNIVERSITY PARK, PA. Search for other works by this author on: GSW Google Scholar J. C GRIFFITHS J. C GRIFFITHS SCRIPPS INSTITUTE OF OCEANOGRAPHY, LA JOLLA, CALIF.; PENNSYLVANIA STATE UNIVERSITY, UNIVERSITY PARK, PA. Search for other works by this author on: GSW Google Scholar GSA Bulletin (1955) 66 (9): 1075–1096. https://doi.org/10.1130/0016-7606(1955)66[1075:SAROQG]2.0.CO;2 Article history received: 15 Jan 1954 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation J. R CURRAY, J. C GRIFFITHS; SPHERICITY AND ROUNDNESS OF QUARTZ GRAINS IN SEDIMENTS. GSA Bulletin 1955;; 66 (9): 1075–1096. doi: https://doi.org/10.1130/0016-7606(1955)66[1075:SAROQG]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Sphericity of quartz grains in sediments determined by three dimensional measurement varies from 0.5 to 1.0 around a mean of 0.75 sphericity units and is approximately normally distributed. Differences in sphericity of quartz grains between arkoses, graywackes, and quartzites are not large and arkoses are least spherical, graywackes intermediate, quartzites most spherical; the differences are not statistically significant on the basis of these 2700 measured grains.The roundness determined by visual comparison of quartz grains from 125 micron size-grade shows a similar trend from least round in arkoses to most round in quartzites, but the frequency distribution of roundness is markedly nonnormal and the conclusions based on statistical analysis are approximate.The magnitude of variation in sphericity and roundness in arkoses is greatest among grains and least among samples, in low rank gray wackes it is moderate in both, whereas in quartzites it is least among grains and greatest among samples; this difference requires a sampling plan specifically designed for each rock type if the analysis of shape of quartz grains is to lead to significant differences at the formation level. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.