This sample of metaconglomerate clearly shows the flattened, stretched
pebbles characteristic of this rock.Return to the Metamorphic Rocks page.
METACONGLOMERATE The parent rock for metaconglomerate is the sedimentary rock conglomerate. The latter tends to form from large, rounded sediment grains such as pebbles and cobbles depoisited by a stream. As such a sedimentary deposit becomes buried, compaction and cementation occur forming conglomerate rock. If burial continues to great depth, the pebbles and cobbles become more flattened and stretched out. Recrystallization of the pebbles and cobbles, and surrounding sediment grains also occurs. Metaconglomerates are high-grade metamorphic rocks.
This sample of metaconglomerate clearly shows the flattened, stretched
pebbles characteristic of this rock.
A
closer view of a sample similar to the one above. This photo is courtesy of
Dr. Stanley Finney, CSU Long Beach.
A comparison of metaconglomerate (above) to conglomerate (below). Enlarge the
image to see how widely separated the pebbles are from each other in the conglomerate as
compared to the metaconglomerate.
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