Types of Sediment - Clastic, Chemical, Biogenic

Clastic Sediment - The "broken" parts of weathered rock. Grain size of clastic sediments range from boulder down to submicroscopic clay particles.

Features of clastic sediments

Sorting - is the measure of range of particle size of sediments. A sediment having a wide range of particle size is said to be poorly sorted and if the range is small, the sediment is said to be well sorted.

Particle Shape - Mechanical weathered particles broken from bedrock tend to be angular. However, nearly all such weathered particles become smooth and rounded as they are transported by water or air.

Rhythmic Layering - Some sediments display a distinctive alternation of parallel layers having different properties such as grain size and sorting.

Cross Bedding - refers to beds that are inclined with respect to a thicker stratum within which they occur. Marine, fluvial, and eolian sediments may all be cross bedded.

Conglomerate - range of particle size varies from 2 mm (a pebble) to more than 256 mm (a boulder).

Sandstone - range of particle size varies from 1/16 mm to 2 mm (sand).

Siltstone - range of particle size varies from 1/256 mm to 1/16 mm (silt)

Shale and Mudstone - range of particle size is less than 1/256 mm (clay)

Types of Chemical Sedimentary Rocks - Rock Salt (Halite), Gypsum, Chert (silica). Mineral Deposits include iron and phosphorus deposits)

Biogenic Sediment - a sediment composed mainly of fossil remains.

Siliceous Biogenic Sediment -

Diatomite - composed of the remains of algae (diatoms).

Radiolarian chert - composed of the remains of floating protozoa called radiolarians

Limestone - carbonate-secreting organisms precipitate calcite or aragonite in building their hard parts.

Dolostone - often after deposition part of a limestone deposit is converted to dolomite with the addition of Magnesium.

Plant Matter - whenever organic matter is buried, a small portion of it escapes decay.

Diagenesis - all chemical, physical, and biological changes that affect sediment after its initial deposition.

Nonmarine Sedimentary Environments -

Stream Sediments - streams constitute the principal agency for transporting sediments across the land. Types of stream environments include the alluvial fan, river channel, flood plain, and delta. Stream deposits are called fluvial deposits.

Glacial Sediments - sedimentary debris eroded and transported by glacier is either deposited along the glacier's base or is released at the glacier margin as melting occurs. Glacial sediment is commonly called till and consists of unsorted mix of unweathered boulders, coddles, pebbles, sand, silt and clay.

Estuarine Sediments - Sediments in a semi-enclosed body of coastal water within which seawater is diluted with fresh water.

Deltaic Sediments - marine deltas build outward into the sea.

Beach Sediments - quartz, the most durable of common minerals in the continental rocks, is a typical component of beach sands.

Offshore Sediments - some fine-grained sediment, carried in suspension, reaches the outer shelf.

Carbonate Shelves - carbonate biogenic sediments accumulate on the continental shelves wherever the influx of land-derived sediment is minimal and the climate and sea surface temperature are warm enough to promote growth of carbonate -secreting organisms. For example, a broad, flat carbonate shelf surrounds the numerous islands of Bermuda.

Continental Slope and Rise - Gravity-driven currents consisting of dilute mixtures of sediment and water having a density greater than the surrounding water move down the continental slope and into the deep ocean.

Turbidites - a graded layer of sediment due to the rapid, continuous loss of energy in the moving current.