EARTH SCIENCE

• EARTH SCIENCE

  name for all the sciences that collectively seek to understand Earth and is neighbors in space
• EARTH SCIENCE

  includes geology, oceanography, meteorology, and astronomy.
• TOPIC: HOW OLD IS THE EARTH?

  Today, scientists claim that the Earth is between 4 and 5 billion years old.
• TOPIC: HOW OLD IS THE EARTH?How did they get this information?

  • Much of the information came from the study of rocks because changes in them occur very slowly
• TOPIC: HOW OLD IS THE EARTH? Law of Superposition

  This law states that in undisturbed sedimentary rocks, each layer is younger than the layer below it and older than the layer above it.
• radioactive dating

  reliable way to tell the Earth's age
• Fossils

  • hardened remains or imprints of organisms that lived a very long time ago
• Paleontologists

  • scientists who study plant and animal fossils.
• Ice and Amber

  • materials that can prevent decay
• Amber

  • one of the materials that can prevent decay
  • hardened resin formed by coniferous trees
• Scientists have divided the story of living creatures into chapters. Each chapter shows the dominant family of living creatures that existed. The chapters in the story of the earth comprise the geologic time scale
• All geologic time up to 600 million years ago is called the Precambrian era
• Geologic Time Scale chronological order

  1. Precambrian era
  2. Paleozoic era (ancient life)
  3. Mesozoic era (intermediate life)
  4. Cenozoic era (recent life)
• Paleontologists estimated the Precambrian Era to have lasted from the beginning of the earth to about 600 million years ago
• TOPIC: GEOLOGIC TIME SCALE

  Precambrian Era

  • Structures produced by algae, sponges, and probably worms prove that primitive organisms did exist.
• TOPIC: GEOLOGIC TIME SCALE

  Precambrian Era

  Most of the exposed Precambrian rocks are igneous or metamorphic
• TOPIC: GEOLOGIC TIME SCALE

  Paleozoic Era

  The Paleozoic Era is divided into seven periods
• TOPIC: GEOLOGIC TIME SCALE

  Paleozoic Era

  • Many fossils from the Paleozoic era were found in layers of sedimentary rocks
• TOPIC: GEOLOGIC TIME SCALE

  Paleozoic Era

  • Marine invertebrates probably lived near the shores of shallow waters. Fossils of trilobites and brachiopods were found preserved in rocks.
• TOPIC: GEOLOGIC TIME SCALE

  Paleozoic Era

  • By the middle of this era, marine life forms had developed shells. These shells formed beds of limestone and coral reefs.
• TOPIC: GEOLOGIC TIME SCALE

  Paleozoic Era

  • The first animal to succeed in adapting itself to breathe air was an amphibian that came out of the sea during the Devonian Period
• TOPIC: GEOLOGIC TIME SCALE

  Paleozoic Era

  Land plants also began to develop during this period. Giant ferns and marsh plants provided food to land animals which increased in number.
• TOPIC: GEOLOGIC TIME SCALE

  Paleozoic Era

  • Marine life also developed.
• TOPIC: GEOLOGIC TIME SCALE

  Paleozoic Era

  • Clams and snails increased in number.
• TOPIC: GEOLOGIC TIME SCALE

  Paleozoic Era

  • Fish became more abundant and showed a greater variety of form.
• TOPIC: GEOLOGIC TIME SCALE

  Paleozoic Era

  • the era that showed the appearance of reptiles
• TOPIC: GEOLOGIC TIME SCALE

  Paleozoic Era

  • Towards the end of this era, the land climate changed.
• TOPIC: GEOLOGIC TIME SCALE

  Paleozoic Era

  • because of the land climate change, many kinds of plants such as land ferns grew during this era.
• TOPIC: GEOLOGIC TIME SCALE

  Mesozoic Era

  The early _________ Era saw the formation of several continents
• TOPIC: GEOLOGIC TIME SCALE

  Mesozoic Era

  • North America began to part from Europe and probably, South America and Africa began to drift apart.
• TOPIC: GEOLOGIC TIME SCALE

  Mesozoic Era

  • By the end of the era, Australia, New Zealand and India had all left Africa, though Arabia still remained attached.
• TOPIC: GEOLOGIC TIME SCALE

  Mesozoic Era

  With the formation of continents, new bodies of water were formed.
• TOPIC: GEOLOGIC TIME SCALE

  Mesozoic Era

  • Scientists have found footprints, eggs, bones, and other fossils of reptiles which existed during the this era.
• TOPIC: GEOLOGIC TIME SCALE

  Mesozoic Era

  The largest creatures that existed during this era were dinosaurs.
• TOPIC: GEOLOGIC TIME SCALE

  Mesozoic Era

  • Dinosaurs: They were believed to be descendants of the primitive reptiles that have survived from the Paleozoic era. However, a current theory suggests that they were ancestors of birds.
• TOPIC: GEOLOGIC TIME SCALE

  Mesozoic Era

  classification of dinosaurs during the Mesozoic era:

  1. dinosaurs that were carnivores with bodies adapted for eating other dinosaurs
  2. dinosaurs that were herbivores with digestive organs adapted for a vegetarian diet
• TOPIC: GEOLOGIC TIME SCALE

  Mesozoic Era

  Tyrannosaurus: The largest meat-eating dinosaur that was 6 m tall and 15 m long
• TOPIC: GEOLOGIC TIME SCALE

  Mesozoic Era

  Towards the end of this era , more continents broke up. North and South America, Australia, Africa, and India became separate plates. The plates drifted north and south until they reached their present positions. Gradually, dinosaurs and other life forms died.
• TOPIC: GEOLOGIC TIME SCALE

  Cenozoic Era

  • As mountains were uplifted, new life forms started appearing
• TOPIC: GEOLOGIC TIME SCALE

  Cenozoic Era

  • Volcanic activity was also widespread, forming immense flow of lava and basalt.