1. Education

QFL Provenance Diagram

Sedimentary Rock Classification Diagrams


This diagram is used to interpret the ingredients of a sandstone in terms of the plate-tectonic setting of the rocks that produced the sand. Q is quartz, F is feldspar and L is lithics, or rock fragments that are not broken down into single-mineral grains. (more below)
Sourcing sandstones

Click the image for the full-size version.

(c) 2013 Andrew Alden, licensed to About.com (fair-use policy)
The names and dimensions of the fields in this diagram were specified by Bill Dickinson and colleagues in 1983 (GSA Bulletin vol. 94 no. 2, pp. 222–235), on the basis of hundreds of different sandstones in North America. As far as I know, this diagram has not changed since then. It is an essential tool in studies of sediment provenance.

This diagram works best for a sediment that does not have a lot of quartz grains that are actually chert or quartzite, because those should be considered lithics instead of quartz. For those rocks, the QmFLt diagram works better.

  1. About.com
  2. Education
  3. Geology

©2014 About.com. All rights reserved.