Sedimentary Rocks

Question 1

what does sandstone form from

Answer 1

sand grains

Question 2

where might sandstone have formed

Answer 2

beach, desert, near water

Question 3

sediment

Answer 3

tiny pieces of broken-down (weathered) rocks

Question 4

depositional environment

Answer 4

the place where sediments end up

Question 5

weathering

Answer 5

The break-down and chemical changes of rocks at or near the earth’s surface

Question 6

which is more dense, continental plates or oceanic plates?

Answer 6

oceanic plates

Question 7

what are continental plates mostly made of?

Answer 7

granite (felsic rock)

Question 8

what are oceanic plates made of?

Answer 8

basalt (mafic rock)

Question 9

chemical weathering

Answer 9

changes minerals into a new substance

Question 10

mechanical weathering

Answer 10

breaks down rock into smaller pieces of the same type of rock

Question 11

erosion

Answer 11

the moving of material / transportation of sediments

Question 12

4 agents of erosion

Answer 12

water, ice, wind, gravity

Question 13

what happens when an agent of erosion slows down or weakens?

Answer 13

the sediments it is carrying settle / are deposited

Question 14

what sediments settle first?

Answer 14

larger sediments

Question 15

what two processes are necessary to convert sediment into sedimentary rock?

Answer 15

compaction, cementation
together called lithification

Question 16

what are the 4 classifications of sedimentary rocks?

Answer 16

biochemical, chemical, clastic, organic

Question 17

clastic

Answer 17

pieces of other rocks

Question 18

chemical

Answer 18

mineral grains

Question 19

biochemical

Answer 19

formerly living

Question 20

organic

Answer 20

plant material

Question 21

would a piece of sand have traveled far from its original rock or stayed close?

Answer 21

traveled far

Question 22

where can you find sand/sand sized sediments

Answer 22

desert, ocean

Question 23

difference between conglomerate and breccia

Answer 23

conglomerate - rounded particles (traveled far from original source)
breccia - sharper particles (stayed close to original source)

Question 24

what agent of erosion could carry pebble sized particles far from their source rock?

Answer 24

water

Question 25

what sized particles make up shale

Answer 25

clay or mud

Question 26

what information does particle size give geologists?

Answer 26

the environment in which the sediment was deposited | how far away from the origional source

Question 27

what can gravel and pebbles be carried by?

Answer 27

landslides, glaciers, rivers

Question 28

how does chemical limestone form

Answer 28

when chemical changes or high water temperatures cause calcite to precipitate

Question 29

how could you tell if a rock is limestone

Answer 29

if it fizzes in contact with hydrochloric acid (HCI)

Question 30

lithification

Answer 30

the process by which sediments are transformed into solid sedimentary rock

Question 31

compaction

Answer 31

weight of overlying material compresses the deeper sediments

Question 32

cementation

Answer 32

as sediments are moved through water, open spaces between sediments are filled and turned into solid rock

Question 33

special qualities of calcite

Answer 33

fizzes in contact with HCI

Question 34

special qualities of silica

Answer 34

produces the hardest rocks

Question 35

special qualities of iron oxide

Answer 35

an orange/red color

Question 36

what are strata what can we learn from them

Answer 36

parallel layers in rocks that form from the accumulation of rocks records what the environment was like when the sediment was deposited

Question 37

what are bedding planes what can we learn from them

Answer 37

Mark the end of one episode of Cementation and the beginning of the next records change in the environment

Question 38

what are fossils what can we learn from them

Answer 38

traces or remains of pre-historic life knowing what animals and plants lived in an area can teach us about what the environment was like when they were alive from their adaptations

Question 39

what is the difference between weathered rocks and unweathered rocks?

Answer 39

weathered rocks are smaller and rounder