L3-L4 | ROCK

• IGNEOUS ROCKS

  • Forms from solidification and cooling of lava or magma
• 2 TYPES OF IGNEOUS ROCKS:

  1. intrusive / plutonic igneous rock
  2. extrusive / volcanic igneous rock
• INTRUSIVE / PLUTONIC IGNEOUS ROCK

  • Magma solidifies
  • Cools down slowly because they are formed under the earth’s surface, when the magma chamber’s force is not enough to force them (magma) up.
• EXTRUSIVE / VOLCANIC IGNEOUS ROCKS

  • Lava solidifies
  • Cools down quickly because they are formed on the surface (lava)
  • May be vesicular → contains air bubble
• • These exposed igneous rock will be sediments → due to the weathering or explosion, or erosion on the surface
• WEATHERING

  • Disintegration or breaking down of rocks (sedimentary)
  • PHYSICAL WEATHERING - Changing of the big rocks to smaller pieces.
  • CHEMICAL WEATHERING - Acid rain (weakening of the rocks)
• EROSION

  • Displacement or transportation to another, usually at the bodies of water.
• AGENTS OF EROSION

  • Those who carries these rocks to the bodies of water
  • Wind
  • Water
  • Human factors
  • Animal factor
  • Waves 
  • Glacier 
  • Gravity (big factor)
• • If these rocks are brought to the bodies of water, they would be buried (deposition)
  • These rocks will be compacted and cemented, along with other rocks becoming a sedimentary rock
• SEDIMENTARY ROCKS

  • Formed from pre-existing rocks or pieces of living organism
  • Forms from the compaction and cementation of sediments
• COMPACTION

  • Due to the weight above the rocks
• CEMENTATION

  • Chemicals underwater segments the sediments
• 2 TYPES OF SEDIMENTARY ROCKS

  1. clastic sedimentary rocks
  2. non-clastic sedimentary rocks
• CLASTIC SR

  • Coming from the sediments made of rocks (gathered)
  • Form from fragments of pre-existing rocks
• NON-CLASTIC SR

  • minerals that have precipitated from water or have been formed through biological process
• METAMORPHIC ROCKS

  • Rocks that are subjected to high heat, high pressure, hot mineral-rich factors, or combination of these factors. 
• ROCK CYCLE

  • transformations of one type of rock to another
• TYPES OF METAMORPHIC ROCKS:

  1. regional METAMORPHIC ROCKS
  2. contact METAMORPHIC ROCKS
• REGIONAL MR

  • Undergoes metamorphism due to the pressure
  • Occurs in a regional/large scale
  • Creates foliated metamorphic rock
• CONTACT MR

  • Undergoes metamorphism due to the heat
  • Occurs on relatively small scale
  • Creates non-foliated metamorphic rock
• ROCKS

  • Aggregate of minerals
  • Can be composed of single mineral or commonly, as an aggregate of two or more minerals 
• TYPE OF IGNEOUS ROCKS BASED ON COMPOSITION

  1. felsic
  2. intermediate
  3. mafic
  4. ultramafic
• FELSIC

  • >65% silica content
  • light colored
• INTERMEDIATE

  • 55-65% silica content
• MAFIC

  • 45-55% silica content
• ULTRAMAFIC

  • < 45% silica content
  • dark colored
• • low silica content, high metal content, high temperature
• INCREASING METAMORPHISM

  • shale -> slate -> phyllite -> schist -> gneiss
• MINERAL OCCURRENCE

  • Concentration of the mineral that is of scientific or technical interest.
• MINERAL DEPOSIT 

  • Mineral occurrence of sufficient size and grade with concentration to enable extraction under the most favorable conditions.
• ORE DEPOSITS

  • Mineral deposits that have been tested and known to be economically profitable to mine.
• AGGREGATE

  • Rock or mineral used as a filler in cement, asphalt, plaster, etc.
  • Generally used to describe nonmetallic deposits.
• ORE

  • Naturally-occurring material from which a minerals of economic value can be extracted
• TYPES OF MINERAL RESOURCES

  • magmatic ore deposits
  • hydrothermal ore deposits
  • sedimentary ore deposits
  • placer ore deposits
  • residual ore deposits
• MAGMATIC ORE DEPOSITS

  • concentrated within a body of igneous rock
• MAGMATIC PROCESSES:

  • crystal fractionation
  • partial melting
  • crustal settling
• 2 TYPES

  • crystal settling
  • fractional crystallization
• SEDIMENTARY ORE DEPOSITS

  • concentrated by chemical precipitation from lakes or sea water.
• 2 TYPES OF SEDIMENTARY:

  1. evaporite deposits
  2. iron formation
• HYDROTHERMAL ORE DEPOSITS

  • concentration of valuable substance by hot aqueous (water rich) fluids flowing through fractures and pore spaces in rocks.