Do You Remebmer?Sedimentary Rocks

Chapter 6

What Are Sediments?• ______________________

• In order of decreasing size

Sources of Sediments1. From ________ & ________

2. From ______ precipitation

What Happens to Sediments

1. ____________ by:– Water.– Ice.– Wind.– Gravity.

• Most sediment is buried and converted to sedimentary rock.

2. _________ by• Rivers• Wind• Glaciers• Other water

• When the transportation vector has run out of energy, the sediments are deposited (dropped).

What Happens to Sediments

____ Sorting- Transporting & Depositing

Headwaters Mouth

Grade = change in elevation/length

Principle of _____ __________ Most sedimentary layers of rock are deposited in a horizontal

position, with older rocks laid down first

_________ Sediment becomes sedimentary rock

through ________, which involves:

• _________

• _________

• Recrystallization (of carbonate sediment)

• Ex: sandRemember that SiO2 is released into groundwater from the chemical weathering of quartz and feldspars.

3 Classes of Sedimentary Rock_______ - fragments of

rock debris produced by physical weathering. Ex. Sand & clay.

_______- sediment precipitates from solution in water. Ex. Calcium carbonate & salt.

_______ - sediment composed of the fossilized remains. Ex. Coal, oil, & natural gas.

Gravel Clastic Rocks

• If rounded clasts = ____________

• If angular clasts = __________

Sand Clastic RocksDifferent Sandstones based on

dominate grains

• quartz grains = ________ ____________

• feldspar grains = _______

• sand-sized rock fragment grains = __________

Clay Clastic Rocks• Grains less than 1/256

mm (smooth)

• _____ (if fissile – splits)

• ________ (if massive)also called Claystone

Chemical ________From the evaporation of

water (usually seawater). • Rock salt - composed of

halite (NaCl). • Rock gypsum -

composed of gypsum (CaSO4.2H20)

• Travertine - composed of calcium carbonate (CaCO3), and therefore, also technically a carbonate rock

Chemical __________• Formed through both chemical & biochemical processes. • Include the limestones (many types)• Two minerals are dominant:

– Calcite (CaCO3) – Dolomite (CaMg(CO3)2)

Chemical ___________Dominated by silica (SiO2). • From diatoms, radiolarians,

or sponges.

• Diatomite - looks like chalk, but doesn’t fizz in acid. Made of diatoms. Also referred to as Diatomaceous Earth.

• Chert - Massive and hard, microcrystalline quartz. May be dark or light in color. Often replaces limestone. Does not fizz in acid.

Biogenic (______) Sedimentary Rocks Coals • organic matter (plants).• Increasing depth of burial

(temperature and pressure): – Peat (porous, brownish

plant fragments)– Lignite (crumbly and

black) – Bituminous (dull to shiny

and black; sooty; layers may be visible)

– Anthracite (extremely shiny and black; low density; not sooty

___________ from Sediments• Large enough to be recognized.• Ex.- haystack rock, sand dunes, delicate arch,

balanced rock

___________ Environments

• Aluvial Fan

• Braided stream

• Lakes

• Rivers

• Levees

• Swamps

• Deserts

• Glacial

________ Environments

Seas & oceans

• Continental shelf

• Continental slope and rise (deep sea fans)

• Abyssal plain

• Reefs

____________ Environmentsbetween the land and the sea.

• How can sedimentary rock help us learn about

the past?

• What can sedimentary rock teach us about the

past?