Conglomerate (geology)

**Classification of Conglomerates**:
– Named and classified by amount and type of matrix present.
– Classified by composition of gravel-size clasts they contain.
– Sorted based on size range of gravel-size clasts present.
– Method depends on type and detail of research being conducted.
– Named according to roundness of gravel.

**Conglomerate Texture**:
– Contains at least 30% of rounded to subangular clasts larger than 2mm in diameter.
– Space between clasts filled by a mixture of silt, sand, and clay known as matrix.
– Paraconglomerates have gravel clasts floating within the matrix.
– Orthoconglomerates are typically cross-bedded and well-cemented.
– Reflect differences in deposition: paraconglomerates often glacial tills or debris flow deposits, while orthoconglomerates are associated with aqueous currents.

**Clast Composition**:
– Classified by composition of clasts as monomict, oligomict, or polymict conglomerates.
– Source indicated by lithology of gravel-size clasts.
– Extraformational conglomerates have clasts significantly different from matrix.
– Intraformational conglomerates have clasts consistent with matrix lithology.
– Two types: shale-pebble and flat-pebble conglomerates.

**Sedimentary Environments**:
– Deposited in deepwater marine, shallow marine, fluvial, alluvial, and glacial environments.
– Turbidites in deepwater marine settings have well-sorted conglomerates.
– Basal conglomerates in shallow marine settings represent shoreline positions.
– Fluvial conglomerates are well rounded and poorly sorted.
– Fanglomerates in alluvial environments are associated with debris-flow deposition.

**Examples and Miscellaneous**:
– Various examples of conglomerates found on Earth and Mars.
– Metaconglomerate: Metamorphic alteration changes conglomerate into metaconglomerate.
– Related concepts: Puddingstone, Jasper conglomerate.
– References for further reading on sedimentology and stratigraphy.https://en.wikipedia.org/wiki/Conglomerate_(geology)