link to main US Geological Survey website
125 Years of Science for America - 1879 to 2004
U.S. Geological Survey
Bulletin 2209-G

Tentative Correlation Between CIPW Normin pl (Total Plagioclase) and Los Angeles Wear in Precambrian Midcontinental Granites -- Examples from Missouri and Oklahoma, with Applications and Limitations for Use

By George H. Davis


photograph granite quarry
Rock of Ages Quarry in the Barre Granite, Barre, Vt. Large blocks from this quarry are predominantly used as monument stone and for sculpting; waste rock is crushed to desired grade and used as aggregate in asphalt by the Vermont Department of Transportation.

The normative chemical classification of Cross, Iddings, Pirsson, and Washington (CIPW) is commonly used in igneous petrology to distinguish igneous rocks by comparing their magmatic chemistries for similar and dissimilar components. A potential use for this classification other than in petrologic studies is in the rapid assessment of aggregate sources, possibly leading to an economic advantage for an aggregate producer or user, by providing the opportunity to determine whether further physical testing of an aggregate is warranted before its use in asphalt or concrete pavement. However, the CIPW classification currently should not be substituted for the physical testing required in specifications by State departments of transportation. Demands for physical testing of aggregates have increased nationally as users seek to maximize the quality of the aggregate they purchase for their pavements. Concrete pavements are being laid with increased thicknesses to withstand increasing highway loads. New pavement mixes, most notably Superior Performance Asphalt Pavement ("Superpave"), are designed for additional service life. For both concrete and asphalt, the intent is to generate a durable pavement with a longer service life that should decrease overall life-cycle costs.

Numerous aggregate producers possess chemical-composition data available for examination to answer questions from the potential user. State geological surveys also possess chemical-composition data for stone sources. Paired with the results of physical testing, chemical- composition data provide indicative information about stone durability and aggregate strength. The Missouri Department of Transportation has noted a possible relation among coarse-grained Precambrian granites of the midcontinental region, correlating the results of abrasion testing with the contents of normative minerals, also known as normins, calculated from chemical composition data. Thus, normin pl ( total plagioclase) can predict, by way of simple regression, the Los Angeles wear for granite samples collected in Missouri. The results of this abrasion testing were extended to another granite in Oklahoma where normin pl predicted Los Angeles wear to within 0.6 percent. This relation may also exist for granitic rocks outside the Oklahoma-Missouri region, as well as for other igneous-rock types.

Download this report as a PDF document (952 KB)

For questions about the content of this report, contact James Bliss

Go to other chapters in USGS Bulletin 2209: Bliss, J.D., Moyle, P.R., and Long, K.R., eds., 2002, Contributions to industrial-minerals research: U.S. Geological Survey Bulletin 2209.

Version history

Download a copy of the latest version of Acrobat Reader for free.

| Help | PDF help | Publications main page | Western Region Bulletins |
| Geologic Division | Western Mineral Resources Program |

This report is available only on the web.

| Department of the Interior | U.S. Geological Survey | Privacy Statement | Disclaimer | Accessibility |
URL of this page:
Maintained by: Michael Diggles
Created: August 16, 2004
Last modified: March 19, 2007 (mfd)