sedimentary rocks

Question 1

How are sedimentary rocks formed?

Answer 1

at or near the surface of the earth

1. Erosion
2. deposition
3. compaction
4. cementation

no heat or pressure involved

Question 2

Define Strata

Answer 2

Layers of rock

Question 3

Define Stratification

Answer 3

The process in which sedimentary rocks are arranged in layers

Question 4

What are the major types of sedimentary rocks?

Answer 4

Clastic
Chemical
Biochemical
Organic

Question 5

Clastic

what are they composed of

Answer 5

they are composed of fragements of rock cemented together with calcite or quartz

Question 6

How are clastic rocks formed?

Answer 6

they form when broken bits of other rocks that were eroded and deposited a long time are squeezed together.

Question 7

Describe the particle size of clastic rocks

Answer 7

sand/large and jagged

examples:
1. shale
2. sandstone
3. breccia

Question 8

Properties: Conglomerates

Answer 8

• poorly sorted particles
• well-rounded particles
• gravel-sized particles

Question 9

Properties of Breccia

Answer 9

• poorly sorted particles
• angular grains
• gravel-sized grains

Question 10

Properties of Sandstone

Answer 10

• well sorted particles
• particles can be angular to rounded
• sand-sized particles

Question 11

Properties of Shale

Answer 11

• microscopic grain size
• grains cannot be seen by the naked eye
• consists of silt and clay size grains
• occur in quiet depositional environments

Question 12

How are chemical sedimentary rocks formed?

Answer 12

When the minerals that are dissolved in a solution and crystallize

Example; Limestone is formed when calcite in dissolved in lakes

and crystallizes

Question 13

How are chemical sedimentary rocks classified?

Answer 13

• Inorganic rocks
• Biochemical rocks

Question 15

Define inorganic rocks

Answer 15

not produced by living things

Question 16

define Biochemical rocks

Answer 16

produced by or are remnants of living things

eg shell fragments, coral reefs, etc

Question 17

Examples of inorganic limestone

Answer 17

• oolitic limestone
• travertine

Question 18

Examples of biochemical limestone

Answer 18

• chalk
• coquina

Question 20

properties: travertine

Answer 20

• common in caves
• happens when limestone is precipitated out of underground water

Question 22

properties: coquina

Answer 22

consists of loosely cemented shell fragments

Question 23

Properties: Chert/Flint

Answer 23

• Consists of microcrystalline silica
• major occurences;
  irregular shaped nodules in limestone
  layers of rock

Question 24

Minerals in clastic rocks

Answer 24

* quartz * feldspar * clay minerals