Sedimentary Rocks
• Fossil source rock
• Made from weathered and eroded igneous and metamorphic rocks
• Indicate past climates/environments
• Petroleum, natural gas, iron, aluminum, and sulfur occur in the pores

• Weathering – the disintegration and decomposition of rock at the surface of the
Earth
• Erosion – the incorporation and transportation of material by a mobile agent, such as water, wind or ice
• Sediment – unconsolidated particles created by the weathering and erosion of rock
• Precipitate – process that separates solids from a solution; forms evaporites
• Lithification – process of converting sediments to solid rock by cementation and/or compaction

Detrital Sedimentary Rocks
• Detrital sedimentary rocks can be made of detrital material that consists of mineral grains or rock fragments from the process of mechanical weathering that are transported and deposited as solid particles

Detrital Sedimentary Rocks
Conglomerate; large, coarse rounded grains

Detrital Sedimentary Rocks
Breccia; large, coarse angular grains

Detrital Sedimentary Rocks
Sandstone; primarily composed of medium sized quartz grains (feels sandy)

Detrital Sedimentary Rocks
Siltstone; composed of fine grained quartz and clay

Detrital Sedimentary Rocks
Shale; composed of very fine grains of the mineral clay and quartz

Detrital Sedimentary Rocks
Arkose; composed of reconsolidated particles of minerals such as feldspar and quartz

Sedimentary Rocks
• Chemical sedimentary rocks are composed of chemical material that was previously dissolved in water and later precipitated by either inorganic or organic processes
• Chemical sedimentary rocks formed from the process of water-dwelling organisms are biochemical sedimentary rocks

Chemical Sedimentary Rocks
Coquina; biochemical sedimentary rock containing visible shells, loosely cemented together

Chemical Sedimentary Rocks
Limestone; biochemical sedimentary rock containing fine shells composed of the mineral calcite that have been cemented together with fine, crystalline calcite (will effervesce with HCl)

Chemical Sedimentary Rocks
Chalk; composed of microscopic shells and clay
(diatomaceous earth)

Chemical Sedimentary Rocks
Tufa; light, porous limestone that forms in springs and caves (stalactites & stalagmites)
(will effervesce with HCl)

Chemical Sedimentary Rocks
Rock Salt (halite); formed as water evaporates leaving formerly dissolved material to precipitate

Chemical Sedimentary Rocks
Bituminous Coal; composed of altered plant remains (will burn)

Chemical Sedimentary Rocks
Dolostone; fine to coarse crystalline calcite (will effervesce with HCl)
Sample has dolostone crystals called Celestite

Chemical Sedimentary Rocks
Chert; very fine crystalline quartz (used to make arrow heads and other weapon and tool tips because of conchoidal fractures

Chemical Sedimentary Rocks
Gypsum; composed of fine to coarse crystalline calcium sulfate
Sample has gypsum crystals called Selenite

• Calcite CaCO
3
• Dolomite CaMg(CO
3
)
2
• Quartz SiO
2
• Gypsum CaSO
4
*2H
2
O
• Halite NaCl
Indicator -
• Hydrochloric Acid HCl