Earth Science Test 2

Front 1

Weathering

Back 1

The disintegration and decomposition of material at or near the surface

Front 2

Mass Wasting

Back 2

The transfer of rock material downslope under the influence of gravity

Front 3

Erosion

Back 3

Physical removal of material by a mobile agent; usually water, wind, or ice

Front 4

What are the 2 types of weathering?

Back 4

Mechanical and Chemical

Front 5

Mechanical weathering

Back 5

The physical disintegration of rock into regolith (smaller pieces)

Front 6

What are the 4 processes of mechanical weathering?

Back 6

Frost wedging

Salt crystal Growth

Unloading

Biological Activity

Front 7

Salt crystal growth

Back 7

🔹on rocky shorelines and arid regions

🔹sea spray or salty groundwater penetrates crevices and pore space

🔹water evaporates leaving salt crystals

🔹as crystals grow, rocks weaken

Front 8

Biological activity

Back 8

🔹plant roots grow in fractures wedging rocks apart

🔹burrowing animals remove material to surface

🔹humans blast rock in search of minerals and for road construction

Front 9

Chemical weathering

Back 9

🔹alters the internal structures of minerals by removing or adding elements

Front 10

What is the most important agent in chemical weathering and why?

Back 10

🔹Water

🔹because oxygen is dissolved in water and oxidizes materials

🔹and carbon dioxide (CO2) is dissolved in water forming carbonic acid and alters the material

Front 11

Weathering of Granite

Back 11

🔹potassium feldspar produces clay material, soluble salt (potassium bicarbonate), and silica in solution

🔹silicate minerals produces insoluble iron oxides and clay mineral

🔹Quartz remains unaltered

Front 12

Spheroidal weathering

Back 12

🔹chemical weathering along joints

🔹generates rounded rocks

🔹weathering works inward from exposed surfaces

Front 13

Important factors for rates of weathering

Back 13

🔹surface area

🔹rock characteristics

🔹climate

🔹differential weathering

Front 14

Rate of weathering: surface area

Back 14

🔹mechanical weathering increases surface area

🔹chemical weathering weakens outer portions of some rocks

Front 15

Rates of weathering: rock characteristics

Back 15

🔹mineral composition and solubility

🔹physical features such as joints

Front 16

Rates of weathering: climate

Back 16

🔹temperature and moisture are the most crucial factors

🔹chemical weathering is most effective in areas of warm temperatures and abundant moisture

Front 17

Differential weathering

Back 17

🔹caused by variations in composition

🔹creates spectacular rock formations and landforms

Front 18

Soil

Back 18

A combination of :

mineral matter

organic matter

water

air

Front 19

Mineral Matter in soil

Back 19

weathered rock

Front 20

organic matter in soil

Back 20

enhances water retention

Front 21

water in soil

Back 21

contains soluble nutrients

Front 22

air in soil

Back 22

source of O2 and CO2

Front 23

Soil texture

Back 23

refers to the proportions of different particle sizes

-sand (large size)

-silt

-clay (small sizes)

determines ability to retain/transmit water and air

loam (mixture of all 3 sizes) is best suited for plant life

Front 24

soil structure

Back 24

-soil particles clump together (peds)

-influences ease of cultivation and susceptibility to erosion

Front 25

4 basic soil structures

Back 25

(slower infiltration rates)

-Platy

-Spheroidal

(faster infiltration rates)

-Prismatic

-Blocky

Front 26

Controls of soil formation

Back 26

-parent material

-time

-climate

-plants and animals

-topography

Front 27

Parent material

Back 27

-affects rates of weathering and soil formation

-chemical composition affects soil's fertility

Front 28

Time

Back 28

-important in all geologic processes

-amount of time to evolve varies for different soils

-**more time = thicker soils less resembling parent material

Front 29

climate

Back 29

-most influential control

-hot wet climate produces more highly weathered soils

Front 30

plants and animals

Back 30

-organisms influence physical and chemical properties

-furnish organic matter to soil

Front 31

topography

Back 31

-angle

-orientation influences

Front 32

topography; angle

Back 32

-steep slopes often have poorly developed soils

-optimum is a flat-to-undulating undulating unplanned surface

Front 33

soil profile

Back 33

soil forming processes operate from surface downward

Front 34

Soil Profile:

Horizons in temperate regions

Back 34

O-Organic matter

A-organic and mineral matter

E-little organic matter

--eluviation

--leaching

B-zone of accumulation

C-partially altered parent material

Front 35

Soil Profile:

Topsoil

Back 35

Horizons O and A together