EARTH SCI

• Exogenic processes


  Any process that includes geological phenomena and processes originating externally to the Earth's surface, driven by solar energy and other external influences
• Weathering


  The gradual on-site breakdown of rocks into sediments caused by many factors
• Mechanical weathering


  • The physical breakdown of rock into unconnected grains and/or chunks without any chemical alteration
• Mechanical weathering processes


  • Exfoliation
  • Thermal expansion
  • Wedging
• Erosion


  The separation of weathered and unweathered materials from its substrate due to gravity or agents of transportation
• Wind erosion


  • Erosion where sediments and loose soil are carried by the wind to new locations, resulting in soil loss, soil dryness, soil structure deterioration, soil nutrient and productivity losses, and air pollution
• Glacial erosion


  • Erosion caused by glacier movement, where rocks and ice being carried by glaciers weather against other stones on the Earth's surface
• Ways water/tidal erosion moves sediments


  • Traction
  • Saltation
  • Suspension
  • Solution
• Mass wasting


  The downslope movement of rocks, soil, and ice due to the pull of gravity
• Factors contributing to mass wasting


  • Relief
  • Fragmentation and weathering
• Unbalanced forces that disrupt the equilibrium between downslope and resistance forces in mass wasting


  • Tectonic vibrations/earthquakes
  • Changes in the structure of the slope
  • Material composition
• General motion types in mass wasting

  • Fall
  • Topple
  • Slide
  • Spread
  • Flow
  • Complex
• Deposition


  The process where sediments settle out of the transporting medium, usually associated with water
• Types of deposition areas

  • Glacial
  • Mountainous
  • Desert
  • Lacustrine
  • Fluvial
• Deposition


  The process where sediments settle out of the transporting medium, usually associated with water [Lat. de- ("away") + ponere ("to put, place"), "place elsewhere"]
• Bed


  The layer formed when sediments settle in a new area
• Sorting


  The distribution of grains in a bed
• Lacustrine


  • Adjective used to associate something with lakes
  • Lakes are still water forms due to a lack of underwater currents
  • Coarse sediments carried by connected tributaries are deposited on a lake's margin
  • Silt and clay are deposited from suspension in the deeper parts
• Fluvial


  • In areas of low elevations where rivers are present
  • The velocity of water is slow and commonly carries an assortment of sediments
  • Coarser sediments tumble along the river bed
  • Finer sediments flow in suspension with the water
• Delta


  • Areas where accumulated sediments that have been compacted and lithified at the river's end is connected to a stagnant body of water
  • When rivers enter the stagnant water form, it empties its sediment load into a delta
• Beach


  • Areas containing fine sand and coarse sediments and rocks
  • Ocean waves and tidal currents transport sand into the coastlines, filtering and sorting out the sand to form ripples at the coastlines
• Marine


  • Areas where saltwater is dominant and activity is observed on both surface and deep levels
  • Includes shallow marine, shallow water (carbonate), and deep
• Endogenic processes


  • Any process that includes geological phenomena and processes originating within the Earth's surface
  • Responsible for tectonic changes on the surface by releasing energy from within
  • Attributed to the leftover heat within the planet's crust during its accretion 4.54 billion years ago
  • Heat comes from gravitational energy and disintegration of radioactive elements buried deep within the Earth
• Magma


  Rocks in liquid to semi-liquid form, less dense than actual stones, found in specific locations on Earth
• Generation of Magma

  1. Decompression Melting

  2. Flux Melting

  3. Heat Transfer Melting

  4. Partial Melting
• Crystallization of Magma

  • Rocks that have been extruded to the surface solidify, recrystallizing to a solid form and forming grains
  • Crystallization can also occur underground if the temperature permits it, creating igneous rocks
• Common Minerals

  • Quartz
  • Orthoclase
  • Plagioclase
  • Muscovite
  • Biotite
  • Amphibole
  • Pyroxene
  • Olivine
• Dikes


  • Intrusions that form wall-like sheets
• Sills


  • Intrusions that form tabular layers in between pre-existing rock layers
• Plutons


  • Intrusions with the blob-like appearance and form many configurations
  • Amalgamations of plutons are known as batholiths
• Felsic rocks


  Rocks with higher silica content, as compared to its magnesia and wustite contents
• Mafic rocks


  Rocks with substantially higher magnesia and wustite contents than silica
• Ultramafic rocks


  Rocks made with different kinds of mafic rocks, ensuring that the silica content is low
• Intermediate rocks


  Combinations of felsic, mafic, and ultramafic rocks
• Volcanism


  Geological activity involving volcanoes, which are visible vents—manifestations of rock formation
• Types of Eruption

  • Effusive eruptions (dominant lava flow and formation of fountains and lakes)
  • Explosive eruptions (eject other materials aside from lava, ranging from ash to large pyroclastics)
• Shield volcanoes


  • Form very broad domes with gentle slopes that cover a wide area, mostly made of alternating layers of basaltic lava and cinder accumulation
• Stratovolcanoes or composite volcanoes


  • Made of alternating layers of lava and pyroclastics, generally made of felsic to intermediate rocks, building tall edifices
• Cinder cones


  • Consist of small cones formed by lava spattering, usually made of cinders with mafic compositions
• Metamorphism


  The process where the original rocks (called protoliths) undergo both mineralogical and textural changes due to modifications in its physical and/or chemical environments, altering it without changing its composition through melting or disintegration