construction, major events and principles

• How the GTS was constructed

  Field observations

  • Fossil records

  • Stratigraphic correlations

  •Radioactive dating

  •Paleomagnetic orientations

  •Orbital revolution pattern of the Earth and

  •The duration of the daily rotation of the earth around its axis.
• Major events of GTS

  • mass extinctions,

  • appearance of new species or genera of life,

  • mountain-building movements • drifting of continents

  • spreading of ocean floors

  • widespread glaciations

  • dominance of certain species

  • massive migration of life between land and water are all considered while accounting the geologic time scale.
• miners


  the first people who needed to understand the geological relationship of diff rocks units
• Nicholas Steno,

  a Danish physician (1638-1687), described how the position of a rock layer could be used to show the relative age of the layer who devised the three main principles that underlie the interpretation of geologic time
• The principle of superposition:


  The layer on the bottom was deposited first and so is the oldest
• The principle of horizontality

  All rock layers were originally deposited horizontally.
• The principle of original lateral continuity


  Originally deposited layers of rock extend laterally in all directions until either thinning out or being cut off by a different rock layer.
• strata

  layered rock
• James Hutton


  he thought the surface of the earth was everchanging environment and "the past history of our globe must be explained by what can be seen to be happening now"
• uniformitarianism by James Hutton


  the present is the key to the past
• William Smith


  a surveyor, canal builder, and amateur geologist from England.
• validity of the principle of faunal succession.


  t fossils are found in rocks in a very definite order.
• The principle of biologic succession


  Each Earth's history is unique, resulting in unique fossil remains, allowing for vertical and horizontal correlation of rock layers based on fossil species.
• More than 85% of earth's history falls under this supereon, from 4.6 billionyears ago to 540 million years ago.


  Precambrian Eon
• Hadean Eon

  
  

  Archean Eon

  
  

  Proterozoic Eon

  
  

  Phanerozoic Eon


  Eon under the supereon, Precambrian Eon
• • It was characterized by Earth's formation and it's hellish environment


  Hadean Eon (4.6 bya to 4 bya)
• this is where the solidification of the Earth began


  Hadean Eon
• the origin of the Solar System


  Solar Nebula
• asteroids, comets, moons and planets


  Creations of Solar System
• • Earth had acquired enough mass to hold a reducing atmosphere composed of methane, ammonia and other gases

  term-3

  
  

  • Water from comets and hydrated minerals condensed in the atmosphere and fell as torrential rain, cooling the planet and filling the first oceans with liquid water.

  
  

  • By the end of the Archean, the ocean floor was covered in a living mat of bacterial life.


  Archean Eon (4 Billion Years to 2.5 billion years ago)
• how many percent of continental mass was formed during the Archean Eon

  70%
• Known as the Earth's first life form

  Archean Eon
• the cooling of the Earth began

  archean Eon
• what kind of microscopic prokaryotes are able to obtain carbon to carbon dioxide in the Archean Eon

  chemoautotrophs, anaerobic bacteria
• The appearance of multi-celled animals and the gathering of land masses to form continents

  Proterozoic Eon (2.5 Billion Years ago)
• plate tectonics forced the available shield rock to collide, forming Rodinia . under proterozoic eon


  1.2 bya
• . (Russian term meaning mother land, Earths first continent)


  Rodinia
• coastal waters were filled with rounded colonies of photosynthetic algae in Proterozoic Eon


  stromatolites
• the period last of the Proterozoic Eon, saw the first multicellular organisms.


  Ediacaran Period
• a soft-bodied heterotrophs filled the continental shelf regions around Rodinia


  Autotrophs
• cnidarians, had sac-like bodies and a simple digestive system with a mouth but no anus and caught food using tentacles armed with microscopic stinging cells. Under proterozoic Eon


  ]corals, and jellyfish
• what kind of species are jellyfish and corals belong

  cnidarians
• they are lacking in organs or a nervous system, they lived by drawing water through their bodies and filtering out food particles. Under Proterozoic Eon


  Sponges
• had fluid-filled body cavities and breath through their skin. Proterozoic Eon


  Annelids or segmented flatworms
• enough shield rock had formed to start recognizable geologic processes such as plate tectonics in Proterozoic eon

  2.5 billion years ago,
• Eras Phanerozoic Eon

  Cenozoic era

  
  

  Mesozoic era

  
  

  Paleozoic era
• Cenozoic Era


  This is the most recent among the eras of the Phanerozoic Era
• Cenozoic Era


  this era marks the age of mammals and the first human evolution.
• Mesozoic Era

  This era marks the beginning of dinosaurs, mammals, birds, and plants due to mass extinction.
• Paleozoic Era


  The explosion of diverse marine life and the largest mass extinction of marine organisms