Sedimentary Rocks

• Carbonatic Rocks
• Evaporite rocks
• Terrigenous Rocks
Grain Size
Terrigenous Rocks
Packing
Roundness
Sorting

• Weathering

Turbidite

• Turbidites

Fossils

• Ammonites
• Bivalves
• Brachiopods
• Gastropods
• Trilobites

Sedimentary Minerals

• Anhydrite
• Baryte
• Chalcedony
• Gypsum
• Glauconite
• Magnesite

Texture

• Allochem
• Carbonatic Matrix
• Dolomitization
• Syntaxial Overgrowthn

Rocks

• Ammonitico Rosso
• Arkosic Sandstones
• Bioclastic Grainstone
• Oolitic Ironstone
• Breccia
• Conglomerate
• Encrinite
• Lithic Arenite
• Mudstone
• Oolite
• Orthoconglomerate
• Radiolarite
• Wackestone

Orthoconglomerate

Conglomerate is a sedimentary rock formed from rounded gravel and boulder sized clasts cemented together in a matrix. The rounding of the clasts indicates that they have been transported some distance from their original source (e.g. by a river or glacier), or that they have resided in a high energy environment for some time (e.g. on a beach subject to wave action). The cement that binds the clasts is generally one of either calcite, silica or iron oxide. The matrix can consist solely of the cementing material, but may also contain sand and / or silt sized clasts cemented together among the coarser clasts.

Conglomerates can be further divided in:

• Clast supported (Orthoconglomerates): where the clasts touch each other and the matrix fills the voids; and
• Matrix supported (Paraconglomerates) : consist of a clast-supported rock with less than 15% matrix of sand and finer particles. The clasts are not in contact and the matrix surrounds each clast.

a conglomerate where the clasts represent more than one rock type is termed polymictic (or petromictic), while one where the clasts are of a single rock type are monomictic (or oligomictic). Conglomerate forms in a very energetic environment, where rocks are eroded and carried downhill so swiftly that they aren't fully broken down into sand.

conglomerate sample. From Wikipedia

Conglomerate classification diagram

Bibliography

• E. WM. Heinrich (1956): Microscopic Petrografy. Mcgraw-hill book company,inc
• M. J. Hibbard (1994): Petrography to Petrogenesis. Prentice Hall editore

Photo

Clast supported Conglomerate (Orthoconglomerates). PPL image, 2x (Field of view = 7mm)	Clast supported Conglomerate (Orthoconglomerates). XPL image, 2x (Field of view = 7mm)	Clast supported Conglomerate (Orthoconglomerates). XPL image, 2x (Field of view = 7mm)
Clast supported Conglomerate (Orthoconglomerates). Note the green altered diabase fragment. PPL image, 2x (Field of view = 7mm)	Clast supported Conglomerate (Orthoconglomerates). Note the altered diabase fragment. XPL image, 2x (Field of view = 7mm)	Clast supported Conglomerate (Orthoconglomerates). Note the green altered diabase fragment. PPL image, 10x (Field of view = 2mm)
Clast supported Conglomerate (Orthoconglomerates). Note the altered diabase fragment. XPL image, 10x (Field of view = 2mm)	Clast supported Conglomerate (Orthoconglomerates). Note the green altered diabase fragment. PPL image, 10x (Field of view = 2mm)	Clast supported Conglomerate (Orthoconglomerates). Note the altered diabase fragment. XPL image, 10x (Field of view = 2mm)
Metamorphic fragments. XPL image, 10x (Field of view = 2mm)	Metamorphic fragments. XPL image, 10x (Field of view = 2mm)