earth science

• The mantle lies beneath the crust and extends to about halfway down into the planet.
• The Earth's crust is the outermost layer, composed mainly of silicate minerals.
• The core consists of two parts - an inner solid core and an outer liquid core.
• The outer core is composed mainly of molten iron and nickel, while the inner core is solid.
• Earth's magnetic field is generated by convection currents within the liquid outer core.
• Natural process of breaking rocks into smaller pieces over time. Water, ice, acids, salts, plants, animals, and changes in temperature are all agents of __________

  weathering
• Water, in either liquid or solid form, is often a key agent of _____ and is also called physical weathering and disaggregation, causes rocks to crumble

  mechanical weathering
• changes the molecular structure of rocks and soil.

  chemical weathering
• process transporting weathered material to new locations

  erosion
• 1. Heat from when the planet formed and accreted, which has not yet been lost 2. Frictional heating, caused by denser core material sinking to the center of the planet; and 3. Heat from the decay of radioactive elements. These are the....


  the three main sources of heat inside the earth
• formed when mineral grains line up in parallel layers


  foliated rocks
• formed where mineral grains (crystals) grow and rearrange, but they do not form layers


  non-foliated rocks
• this refers to the changes in mineral assemblage and texture that result from subjecting a rock to conditions such pressures, temperatures, and chemical environments different from those under which the rock originally formed.

  metamorphism
• comes from the greek word meta = after, morph = form


  metamorphism
• 6 types of metamorphism:
• type of metamorphism where rock minerals and texture are changed, mainly by heat, due to contact with magma


  contact metamorphism
• occurs over a wide area. the heat and pressure are created at converge are where plates are colliding. usually produced foliated rocks


  regional metamorphism
• a high pressure metamorphism resulting from the crushing and shearing of rock during tectonic movement, mostly along faults


  calaclastic metamorphism
• rocks that are altered at high temperature and moderate pressure by hydrothermal fluids are hydrothermally metamorphosed


  hydrothermal metamorphism
• when sedimentary rocks are buried to depths of several kilometers, temperatures greather than 300⁰C

  burial metamorphism
• when an extraterrestrial body, such as meteorite or comet impacts the earth or there is a very large volcanic exploision, ultrahigh pressures can be generated in the impacted rock


  shock metamorphism
• metamorphism of shale

  SLATE, foliated rock type
• metamorphism of slate, but under greater heat and pressure than slate


  PHYLLITE, foliated rock type
• Often derived from metamorphism of

  claystone or shale; metamorphosed under

  more heat and pressure than phyllite


  SCHIST, foliated rock type
• metamorphism of various different rocks, under extreme conditions of heat and pressure


  GNEISS, foliated rock type
• contact metamorphism of various different rock types

  HORNFELS, non-foliated rock type
• metamorphism of sandstone

  QUARTZITE, non-foliated rock type
• metamorphism of limestone


  MARBLE, non-foliated rock type
• is the forced applied to a rock 


  stress
• stresses that push towards each other, causing a decrease in the space a rock takes up

  compressional stress
• stresses that pull material in opposite directions

  tensional stresses
• parallel stresses that move past each other in opposite directions


  shear stress
• stress from the weight of material above a buried object; reduces volume


  confining stress
• an acient greek word meaning ''all land'' or ''entire earth''


  pangaea
• is the idea that the continents move. from a single landmass called pangaea


  continental drift
• theory that the earth's outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core

  plate tectonics
• the transfer of thermal energy through the movement of a liquid gas


  thermal convection
• a massive, irregularly shaped slab of solid rock, generally composed of both continental and oceanic lithosphere


  tectonic plate
• the edges where two plates meet


  boundaries
• this is a boundary where plates meet. this happens when two tectonic plates moves towards each other


  convergent (collusion) boundaries