EASC @ Morton High School - Sedimentary Rocks

Sandstone

Detrital, sand grain

Arkose Sandstone

Detrital, sand grain

Conglomerate

Detrital, gravel grain, rounded

Breccia

Detrital, gravel grain, angular

Limestone

Chemical, composition = calcite

Fossil Limestone

Chemical, composition = calcite

Silt/Mudstone

Detrital, mud grain, rounded

Flint

Chemical, composition = quartz 

Travertine Limestone

Chemical, composition = calcite

Jasper

Chemical, composition = quartz

Chert

Chemical, composition = quartz

Coquina Limestone

Chemical, composition = calcite

Rock Gypsum

Chemical, composition = gypsum

Agate

Chemical, composition = quartz

Shale

Detrital, mud grain, rounded

Lithification

Unconsolidated sediments are transformed into sedimentary rocks

Diagenesis 

The alteration of grains after deposition

Detrital

Form from sediments that have been weathered and transported, clastic texture, composed of discrete fragments cemented together

Chemical

Form from precipitated material that was once in solution form, no clastic or crystalline texture, where minerals form patterns of interlocked crystals

Organic

Form from the carbon-rich remains of organisms

Gravel Grain

Conglomerate and Breccia

Sand Grain

Sandstone

Mud Grain

Silt/Mudstone and Shale

Calcite Composition

Limestone, Travertine Limestone, Coquina, Fossil Limestone, Chalk Limestone

Quartz Composition

Chert, Flint, and Jasper

Gypsum

Rock Gypsum

Halite

Rock Salt

Grain size Smallest to Largest

Gravel < Sand < Mud