Sediments are classified based on their particle size. There are four main categories of siliciclastic sedimentary particles: major minerals, accessory minerals, rock fragments, and chemical sediments. Sediments are named based on whether they are loose or consolidated into rock. Loose sediments include boulder, cobble, pebble, sand, silt, and clay depending on their size range. The corresponding consolidated rocks are conglomerate/breccia, gravel, sandstone, siltstone, and claystone/mudstone/shale. Carbonate sediments are comprised of minerals like aragonite, calcite, and dolomite. They generally form limestone when lithified, but can also form dolom

1. Classification of sediments
Lecture 2
Jyoti Khatiwada
Roll no 10

2. Classification of sediments

3. classification and nomenclature of sediments

4. Siliciclastic sedimentary particles
• The composition of siliciclastic sedimentary rocks includes
the chemical and mineralogical components of the
framework as well as the cementing material that make
up these rocks. Boggs divides them into four categories;
major minerals, accessory minerals, rock fragments, and
chemical sediments.
Gravel
sand
clay mixture

5. Classification of clastic sediments

6. classification
Name of
Particle
Size Range Loose
Sediment
Consolidated Rock
Boulder >256 mm Gravel
Conglomerate or Breccia (depends on
rounding)
Cobble 64 - 256 mm Gravel
Pebble 2 - 64 mm Gravel
Sand 1/16 - 2mm Sand Sandstone
Silt 1/256 - 1/16
mm
Silt Siltstone
Clay <1/256 mm Clay Claystone, mudstone, and shale

7. Carbonate sediments

8. Carbonate sediments
• Modern carbonate sediments are comprised of three
principal minerals: aragonite, calcite (CaCO3) and
dolomite (CaMg (CO3)2). The mineral type is
determined by the organism from which the grains are
derived. Once lithified, these will generally form
limestone, although chemical diagenesis or
lithification in specialized conditions that concentrate
magnesium (i.e, evaporation) can form dolomite.
• Classified as biogenic grains and non skeletal grains

9. Sand silt clay classification

10. Gravel Sand clay classification