sedimentary
Conglomerate
Conglomerate (Sedimentary Clastic Rock)
Features rounded clasts (pebbles/cobbles) larger than 2mm embedded in a fine-grained matrix of sand or silt. Color varies from brown to grey; hardness of clasts varies; dull luster; clastic texture.
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Physical properties
Features rounded clasts (pebbles/cobbles) larger than 2mm embedded in a fine-grained matrix of sand or silt. Color varies from brown to grey; hardness of clasts varies; dull luster; clastic texture.
Formation & geological history
Formed by the lithification of rounded gravel, usually deposited in high-energy environments like fast-moving rivers, alluvial fans, or beaches. The rounding indicates significant transport distance.
Uses & applications
Used primarily in the construction industry as fill material, coarse aggregate for concrete, and occasionally as a decorative dimension stone or for landscaping.
Geological facts
Conglomerate is often called 'puddingstone' because it looks like a fruit pudding. It is essential for geologists to understand the past flow direction and energy levels of ancient river systems.
Field identification & locations
Identify by looking for rounded pebbles cemented together by a sandy or silty matrix. Look for it in ancient riverbeds, coastal cliffs, or mountain slopes. Common in many sedimentary basins worldwide.
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