The Earth Through Time, 8e

Eighth Edition
by Harold L. Levin

Chapter 5 - page 8

The Sedimentary Archives

Sands and Sandstones

Sandstone Environmental Interpretation

Each type of sandstone implies something about depositional history and environment:

  1. Quartz sandstone implies a long time in the depositional basin. Deposition typically in tectonically stable, shallow-water environments. Common sedimentary structures are ripple marks and cross-bedding.
  2. Arkose implies a short time in the depositional basin (because feldspar typically weathers quickly to clay). Also implies rapid erosion, arid climate, tectonic activity, steep slopes. Commonly deposited in fault troughs or low areas along granitic mountains. Often has a pinkish color due to oxidized iron, suggesting continental deposition.
  3. Graywacke implies a tectonically active source area and depositional basin, with rapid erosion. Graded bedding is common. Associated with volcanic rocks, shales, and cherts of deep water origin.
  4. Hand specimen (left) and thin section (right) of graywacke.
    Hand specimen (left) and thin section (right) of graywacke.

  5. Lithic sandstone is characteristic of deltaic coastal plains, and may be deposited in nearshore marine environments, swamps, or marshes. Associated with coal and micaceous shales.

Geologic settings where various sandstones are deposited.
A = Quartz sandstone
B = Arkose
C = Graywacke
D = Lithic sandstone

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Document created by: Pamela J. W. Gore
Georgia Perimeter College, Clarkston, GA

September 17, 2005