Sedimentary Rocks Formation and Classification

These flashcards cover key concepts related to sedimentary rocks, their formation, and classification.

Sediment

Naturally occurring unconsolidated material consisting of loose fragments of bedrock, minerals, shells, and crystals.

Diagenesis

The process by which sediments become consolidated into sedimentary rock through compaction and cementation.

Compaction

The process of pressure squeezing sediments closer together to remove water and form rock.

Cementation

The process in which minerals precipitate to bind sediments together, contributing to lithification.

Lithification

The process of turning sediments into sedimentary rock.

Detrital rocks

Also known as clastic rocks, these are formed from sediments derived from weathered rocks.

Chemical sedimentary rocks

Rocks formed from the precipitation of minerals from a solution, often involving organic processes.

Conglomerate

A type of clastic rock made of rounded pebbles larger than two millimeters.

Breccia

A type of clastic rock composed of angular rubble fragments larger than two millimeters.

Sandstone

A clastic rock with grains smaller than two millimeters but larger than 0.06 millimeters.

Shale

A mudstone that contains well-defined thin layers that can be split easily.

Arco sandstone

A sandstone that contains more than 25% potassium feldspar or orthoclase.

Quartz sandstone

A sandstone primarily made of quartz, indicating extensive weathering.

Carbonate rocks

Rocks that contain the carbonate anion (CO₃), usually composed of calcite or dolomite.

Limestone

A carbonate rock primarily composed of calcite.

Coal

A sedimentary rock formed from the organic remains of plants in anoxic environments.

Chert

A sedimentary rock made of microcrystalline quartz, can be chemically or biochemically formed.

Evaporates

Chemical sedimentary rocks formed from the precipitation of salts from seawater.