Mineral Resources and The Rock Cycle Mineral: naturally occurring, solid, inorganic Material with a crystalline structure and a Definite chemical composition.

Mineral Resources and The Rock Cycle

Mineral: naturally occurring, solid, inorganic Material with a crystalline structure and a Definite chemical composition

Rock: Mixture of mineralsMineral Resource: a minerals

that can extracted and converted into a resource at affordable prices

Natural Hazards

• Earthquakes• Volcanoes• Floods• Mass Movements

Earthquake: stress in earth’s crust can cause solid rock to deform until it suddenly fractures and shifts along the fault

producing a fault.

– Two types of Earthquakes:• Deep-focus: caused when one plate slides under another plate

(subduction), the plate gets jammed and pressure builds up, then with a sudden movement the plate slips under the other causing a very big earthquake.

• Shallow focus: caused by plates sliding past one another. When the plates get locked up and then suddenly move the earthquake is created.

• Epicenter: point on earth’s surface directly above the:• Focus: point where initial movement takes place.• Magnitude: size of quake measured on a logarithmic scale called

the Richter scale.• Tsunami: earthquake generated water wave. • Control of quakes: geologic mapping, examine history records,

building codes, ideally learn to predict

•

Volcanoes: when magma reaches earth’s surface through cracks or fissures

3 Types:

– Composite Cone: large, steep sided, explosive, thick granitic magma, associated with convergent plate boundaries, lots of gas and ash.

• Examples:

Shield Volcano

Shield: flat, non-explosive, lots of liquid basaltic lava, associated with divergent plate boundaries and hot spots

Example:

Mass Wasting: movement of rock by gravity

• slump, creep, rockfalls, landslides, mudflows

• factors that affect mass wasting: steepness of slope, amount of moisture, roads, building, fire

• subsidence: land sinks and forms sinkholes. Caused when underground caves collapse. Can also be from removal of excess oil or groundwater

• Example:

Soil compositionSoil Horizons: series of layers or zones with a distinct

texture and compositionSoil profile: a cross-sectional view of horizons in soil

O-horizon: top layer, surface litter which is leaves and debrisA-horizon: topsoil layer: some inorganic materials and humus which is partially decomposed organic material.

• these two top layers have fungi, bacteria, and protists that break down complex organic solids• A thick topsoil layer is good for crop.

B-horizon: (subsoil) broken down inorganic rockC-horizon: parent rock

Leaching:

• water infiltration occurs when precipitation occurs, this rain washes minerals out of the top layers of soil

Soil Texture: The relative amounts of clay, silt an sand, soil with equal amounts of each are called loams which are the best types for

growing crops

– Soil Porosity: a measure of the volume of pore spaces in the soil

– Soil Permeability: the rate that water moves through the soil, which is determined by soil porosity

– Soil porosity, texture and permeability determine a soils water holding capacity, aeration and workability

• Soil Acidity: (pH), influences the uptake of soil nutrients by plants, also acid soil causes the leaching out of nutrients. PH of 5.5 to 8.5 is an acceptable range for most plants