Archive - Sampling the Bedrock

March 31, 2019

Sampling the bedrock_sm

Each Sunday we present a notable item from our archives. This EPOD was originally published March 31, 2013.

: James Van Gundy
Summary Author: James Van Gundy

The geology of the island of Newfoundland, Canada, is complex and contains a varied mix of igneous, metamorphic and sedimentary rocks. On a beach near Cow Head in Gros Morne National Park the naturally tumble-polished and wetted cobbles featured above clearly show the texture and mineral composition of the rocks from which they were derived.

Glaciers, streams, wave action and gravity have been working on the landscape of western Newfoundland for millions of years. Rocky material found on the island’s beaches gives testimony to these erosive processes and provide a catalog of the bedrock upon which the forces have acted. Cobble beaches are characteristic of shores with vigorous wave action. Waves transport the smaller particles, such as silt and sand, into deep water or along the shoreline to be deposited in more protected locations. Photo taken on September 24, 2012.

Photo Details: Camera: SONY DSLR-A100; Focal Length: 30.0mm (35mm equivalent: 45mm); Aperture: f/5.0; Exposure Time: 0.017 s (1/60); ISO equiv: 125; Software: DSLR-A100 v1.02.