SCIENCE Flashcards
In undisturbed sedimentary rocks, each layer is younger than the layer below it and older than the layer above it
Law of Superposition
T or F: Layered rocks are older than igneous rocks
True
Hardened remains or imprints of organisms lived a long time ago
Fossils
Study plant and animal fossils
Paleontologists
4 Geological Times (Oldest to Most Recent)
Precambrian
Paleozoic
Mesozoic
Cenozoic
Geologic time up to 600 million years ago
Precambrian
Ancient life
Paleozoic
Intermediate life
Mesozoic
Recent life
Epochs
Cenozoic
Beginning of earth until 600 million years ago
Rocks found were almost devoid of fossils
Algae, sponges, worms existed
Too primitive to leave many fossils
History is either buried under young rock or eroded away
Igneous or metamorphic rocks
Precambrian
Divided into 7 periods
Fossils found in layers of sedimentary rocks
Marine invertebrates lived near shores of
shallow waters
1st animal to breathe air is Amphibian during
Devonian Period
Marine life developed
Reptiles appeared in late era
Land climate changed at end of era
Paleozoic
Formation of several continents
With formation of continents, new bodies of water were formed
Changes in plant and animal life
Footprints, eggs, bones, fossils of reptiles
were found
Largest creatures existed (Dinosaur)
Largest meat-eating dinosaur is
Tyrannosaurus
More continents broke up
Dinosaurs died in end if this era
Mesozoic
As mountains uplifted, new life forms appeared
Volcanic activity was present
More mammals with tooth structures for specific diets, limb structures of various
postures, and increasing brain size
Cenozoic
Line drawn around middle of a globe or map
Numbered 0 in latitude
Equator
Drawn east to west
Lines of latitude
North-South line drawn from North to South Pole
Meridian or Longitude
Drawing of earth, part of earth on a flat surface
Map
Spherical model of earth
Globe
Layers of Earth (O to I)
- Crust
- Upper Mantle
- Lower Mantle
- Outer Core
- Inner Core
Thin outermost layer of Earth
All life on Earth exists
Materials found are: silicon, oxygen,
aluminum, calcium, sodium, potassium
Only layer that can be studied directly
Crust
3 Types of Solid Rocks:
Igneous
Sedimentary
Metamorphic
Below crust
Makes up 80% of Earth’s volume
Denser than outermost layer of Earth
Mantle
Surrounds inner core
Made up of liquid iron and nickel
Outer Core
Innermost layer
Contains iron and nickel
Very dense due to intense pressure
Inner Core