science

sciences that seek to study the earth and its neighbors in space

• sun
• wind
• water

A tentative explanation for a phenomenon which can be tested for validity

hypothesis has been extensively tested and has survived detailed scrutiny then the hypothesis can be promoted to the level of theory

• 1)Collection of scientific facts and
• measurements.

• 2)Development of individuals hypothesis
• or models.

• 3)Development of observations and
• experiments to test hypothesis.

• 4)Acceptance, modification or rejection
• of the hypothesis and models based on testing.

The Nebular Hypothesis (gas )

The Planetisimal Hyposthesis (part of the sun)

4.5 billion or 4500 million years old

gases that envelope the earth

all living or once living materals

water on or near the earths surface

rocks and other inorganic mater that make up the earth service

flattened at the poles.

greator than the polar diameter

outer most layer of the earth

contental (land) and oceanic ( ocean) crust

largest in volume and the middle part

the innermost later

broken into pieces that move in relationship with each other resulting in shfting contents valcano eruptions and new crust

plates move towards one another

plates move away for each other

plates slide by one another

cant be broken to other substances

smallest possilbe particle of an element. has all the properties of an element

largest oxygen(O) Silicon(Si) and Aluminum(AL)

atoms are aranged in 3dimensional orderly or regulary repeating

two most abundent elements in the crust

• naturally occuring
• solid
• definite
• definite crystalline structure

Fundamental property. But cannot base the identification on it solely.

• More reliable than color. Obtained by rubbing the mineral on a piece of unglazed porcelain (called streak
• plate). Minerals that are metallic often leave a color on the plate

External appearance of the mineral based on the internal arrangement of atoms.

Resistance of a mineral to scratching. Measured using the Mohs Scale of Hardness ranging from 1 (softest) (talc)to 10 (hardest).(diamond)

the mineral to break in smooth planes

breaks along a haphazard manner

weight of a mineral compared to a equal volume of water

• Smell: Clays have an earth smell.
• Taste: Halite tastes salty.
• Magnetite: Being attracted to a magnet.
• Striations: Plagioclase feldspar exhibits straight parallel lines on its surface.

hydrochloric acid

• wind
• water
• ice

naturally occuring consolidated materals comprising of minerals

relationship between rocks

formed from once molten material called magma

Plutonic rocks are coarser grained (see the crystals) owing to slow cooling.

Volcanic rocks are fine grained (sometimes glassy) owing to rapid cooling.

(Intrusive-slow cooling) form below the surface of the earth. (e.g. granite).

Extrusive-fast cooling) form at or close to the surface of the earth (e.g. basalt).

(sudden chilling) volcanic glass (e.g. obsidian).

intermediate rate of cooling slow and fast (porphyrtic)

Based on texture and mineral composition.

• higher melting point
• less dence

• Rocks that have been formed from material derived from
• preexisting rocks

Lithification is when the sediments are transformed into rocks.

Clastic sedimentary rocks are the products of mechanical breakup of other rocks (e.g. conglomerate, sandstone, and shale).

Chemical sedimentary rocks are not from mechanical but forms via chemical precipitation or growth from solution (e.g. limestone).

Organic sediments consists of carbon rich remains of once living organism (e.g. coal).

carbon

Rocks that have been formed under action of heat and/or pressure of preexisting rocks.

• Contact Metamorphisms: When heat is
• dominating agent (e.g. marble).

Regional Metamorphism: When pressure is the dominant factor (e.g. gneiss).

• Foliation: When the pressureon the rock is too great, then it will result in striations of the rock. With
• increasing pressure the banding becomes more prominent and goes from slate (low pressure)-phyllite, schist, and gneiss (high pressure).

The physical breakdown (disintegration) and chemical alteration (decomposition) of rocks at or near the earth’s surface..

The movement of rock and soil downslope under the action of gravity.

The removal of materials by agents such as wind, water, and ice.

Movement of eroded particles by wind, water, and ice

When transported material comes to rest

• The physical disintegration of the rocks. Breaks up the rocks but does not change the chemical
• composition. E.g., frost wedging, unloading, and biological activity.

• Decomposition of the rock by exposure to water and
• atmospheric gases. Changes the chemical composition and structure. E.g., oxidation, calcite dissolved when chemically weathered. Same effect observed for limestone and marble.

• The weathering of the minerals depends upon the composition of the mineral, as well as the
• internal arrangement of atoms. The weathering sequence is the same as that of the Bowen’s reaction
• series.

we are

• The chemical make up of the rock can establish how quickly a rock can weather. There are some minerals that weather faster in comparison to others. This is
• evident from comparing headstones. For
• instance, headstones made of granite are more resistant than marble ones.

Climatic factors such as temperature and moisture are instrumental in establishing the rate of weathering. For instance, regions with higher temperatures and precipitation will allow for chemical weathering to take place as opposed to colder and drier regions.

Different rates of weathering for different areas. Not all rocks weather uniformly. The weather depending on their composition as well the climatic conditions of the region they are located in.

Formed as a product of weathering.

• Layer of weathered material on top of the
• bedrock, consisting of unconsolidated
• pore spaces, mineral, and organic matter.

The soil texture refers to the proportions of different particle sizes.

• Soil Horizons:
• O-Horizon: Upper most layer. The organic horizon.
• A-Horizon: Dark colored soil. Contains humus.
• Also called the Zone of Loss/Leaching.
• B-Horizon: Accumulation of materials lost from A-Horizon. Also called the Zone of Gain.
• C-Horizon: Incompletely weathered parent material below the B-Horizon.
• R- Bedrock: Unexposed unweathered portion
• of the rock.

Gravity is the controlling force of mass wasting.

When saturated with water the material becomes heavy and more likely to move downslope. As the amount of water in the debris increases the rate of movement increases as well.

Stream undercutting a valley or waves hitting against the base of a cliff. This results in mass wasting as the gradient is steep. Angle of repose is the angle where material remains stable.

Vegetation keeps the soil in place. Removal of vegetation increases the risk of mass wasting

Just an instigation for mass wasting to occur. Earthquake results in ground motion and shaking and this may disturb the material making it unstable and may result in mass wasting.