§6-1 “ Sedimentary Rock”

First Go over Chapter 5 interactive notes & then:

Objectives:

• Name the 3 main types of sedimentary rock & give an example of each.

• Describe several identifiable sedimentary rock features.

Formation of Sedimentary Rocks

• Compaction of sediments– Weight of overlying sediments

“squishes” the fragments together.

• Cementation of sediments– By quartz or calcite

3 Types of Sedimentary Rocks

• #1 CLASTIC • #2 CHEMICAL • #3 ORGANIC

CLASTIC Sedimentary Rocks

Classified by the size of the sediments within the rock

• Rounded pebbles –– Conglomerate

• Angular gravel –– Breccia

• Visible pieces of sand –– Sandstone

• Clay/mud particles –– Shale

CHEMICAL Sedimentary Rocks

Formed from minerals that were dissolved in water

PrecipitationCalcite, Chemical

Limestone

EvaporationGypsum, halite

               

5/6 & 7/8 start here

Organic Sedimentary Rocks

• Formed by once-living organisms

• Examples:– Coquina

• Large sea shells

– Chalk • Microscopic Sea shells

– Coal • dead plants in swamps

– Organic limestone• Fossils• Coral

Coral

Sedimentary Rock Structures

• Stratification• Ripple Marks• Mud Cracks• Fossils• Concretions

3rd period start here on Monday

Stratification

Ripple Marks

Mud Cracks

Fossils

Concretions

Assignments• Work in small groups to separate your “Box of

Rocks” into 3 groups:1- Clastic = Pieces2- Chemical = minerals from water3- Organic = fossils, coral, seashells, coal

• Can you name each rock?• Wash your hands/table & leave box of

rocks on your table.• Begin working on Chapter 6 interactive

note sheets.