Earth Science UNIT 1

Atomic mass

Number of protons and neutrons

Protons

Positively charged particles

Processes of mechanical weathering

frost wedging, salt crystal growth, sheeting, biological activity

Seafloor spreading

process by which new seafloor is created along the ocean ridge

Fracture

property of having chemical bonds that are equally strong in all directions

What causes a flood?

when stream discharge exceeds channel capacity -caused from snowmelt, heavy rainfalls, flash floods

How the Hawaiian islands formed

when the pacific plate moved over a hot spot and island after island rose up out of water as magma hardened

Transform faults

where tectonic plates slide horizontally past each other

Divergent boundaries

(constructive margins) -two plates move apart -upwelling of mantle creates a new sea floor

Convergent boundaries

(destructive margins) -two plates move together -oceanic lithosphere descends and is reabsorbed into mantle

Rocks

-Naturally occuring solid masses of minerals or mineral-like matter such as natural glass or organic material

What evidence supports plate tectonics theory?

-age and thickness of seafloor sediment -hot spot-tracks -magnetic reveals and sea flooring spreading

4 main types of drainage patterns

-dendritic -radial -rectangular -trellis

Classifications of rocks

-igneous, sedimentary, metamorphic

running water erosion

-is the dominant agent of erosion -when it rains, loose material is picked up and carried along by the rainwater running off the surface.

Silicates

-most common mineral group -based on silicon-oxygen tetrahedron -make up 90% of Earth's crust

Youthful stream

-mostly downcutting -steep V-shaped valley -no floodplain -Steep gradient -rapids and waterfalls -Little or no Deposition -straight course -no meanders

Old stream

-mostly side cutting -Very wide valley -very wide floodplain -very gentle gradient -no rapids/waterfalls -Deposition of sediment -back swamps

Minerals

-naturally occurring -inorganic solid -crystalline structure -definite chemical composition

Karst topography

-region in which a layer of limestone close to the surface creates deep valleys, caverns and sinkholes -caused by groundwater dissolution

Quartz

-second most abundant mineral in Earth's crust -common in igneous, sedimentary, and metamorphic rock -variety of colors -only common mineral composed completely of Silicon and Oxygen

evidence behind continental drift

-similarity between coastlines on opposite sides of the Atlantic -identical fossils found in South America and Africa -rock types and geologic features match up -evidence for glaciation on continents that are now tropical

Metamorphism

-the process that leads to change in mineralogy, texture, and sometimes chemical composition -because of chemical processes or changes in temperature and pressure

Water table

-the upper level of the saturated zone of groundwater -irregular and changes during drought

Porosity

-total volume of rock or sediment that consists of open pore space -depends on size and shape, packing, and sorting of grains -high permeability

Ground water

-water held underground in the soil or in pores and crevices in rock -largest reservoir of freshwater

Water Cycle steps

1. Evaporation 2. Condensation 3. Precipitation 4. Run off 5. Transpiration 6. Infiltration

Radial pattern

A system of streams running in all directions away from a central elevated structure (volcano)

Metamorphic rock

A type of rock that forms from an existing rock that is changed by heat, pressure, or chemical reaction (slate, marble, quartzite, schist)

Permeability

Ability of rock or soil to allow water to flow through it

Hydrosphere

All the water at and near the surface of the earth, 97% of which is in oceans

Slate

Fine-grained, low-grade metamorphic rock, formed by the metamorphism of shale

Type of rock most common in caves

Limestone

electrons

Negatively charged particles

Ore

Rock that contains a metal or economically useful mineral

Evaporation

The change of a substance from a liquid to a gas

crystal habit (form)

The overall shape of a crystal

Lithification

The process that converts sediments into solid rock by compaction or cementation (sediment-sedimentary rock)

cone of depression

an area lacking groundwater due to rapid withdrawal by a well

Sedimentary rock

a rock that forms from compressed or cemented layers of sediment (Limestone, Sandstone, shale, coal)

Mohs scale

a series of 10 minerals used as a standard in determining hardness

Dendritic pattern

a stream system that resembles the pattern of a branching tree

Igneous rock

a type of rock that forms from the cooling of molten rock at or below the surface (Granite, Diorite, Obsidian, Basalt)

Cleavage

ability to split easily along smooth, flat surfaces.

Chemical weathering

alters a rock's chemical makeup by changing the minerals that form the rock or combining them with new chemical elements (Water)

Hot spot

area of volcanism, high heat flow, and crustal uplift above a mantle plume

diagnostic properties of minerals

characteristics used for identifying minerals (crystal form, luster, color, streak, hardness, cleavage, specific gravity/taste, feel, double refraction, smell, reaction to acid)

Rectangular pattern

characterized by numerous right angle bends that develops on jointed or fractured bedrock.

most common drainage pattern

dendritic

types of plate boundaries

divergent, convergent, transform

Coarse grained

igneous rock texture in which minerals are easily visible without magnification

Lithosphere

is the crust and uppermost mantle

Trellis pattern

parallel streams with short tributaries meeting at right angles

Biosphere

part of Earth in which life exists including land, water, and air or atmosphere

silicon-oxygen tetrahedron

the basic unit of the structure of silicate minerals; a silicon ion chemically bonded to and surrounded by four oxygen ions

Streak

the color of a mineral's powder

Mass wasting

the downhill movement of a large mass of rocks or soil due to gravity (landslide)

Transpiration

the emission of water vapor from the leaves of plants

Steepest part of a river

the head

Continental Drift Theory

the idea that continents slowly shift their positions due to movement of the tectonic plates on which they ride

Atomic number

the number of PROTONS in the nucleus of an atom

Neutrons

the particles of the nucleus that have no charge

Mechanical weathering

the physical breaking of rock, resulting in smaller fragments

Discharge

the quantity of water in a stream that passes a given point in a period of time

Hardness

the resistance of a mineral to being scratched

Tenacity

the resistance to deforming stresses (ex. bend brittle fashion or elastically)

Plate tectonics theory

the theory that Earth's crust is made up of individual plates that gradually move in relation to each other

Luster

the way a mineral reflects light from its surface

How the Himalayan Mountains were formed

they were formed from continental plates colliding (Indian and Eurasian Plate)

Oceanic crust

thinner, more dense, younger crust making ocean floor

Gradient of a stream

vertical drop over a specified distance (steeper gradient provides more energy)

Run off

water that flows over the ground surface rather than soaking into the ground

Land Subsidence

withdrawing large amount of water sometimes causes sand and rock in aquifers to collapse, which causes the land above the aquifer to subside or sink