Geology Flashcards
Study of the Earth, including its history and physical properties
Geology
Earth’s two weak spots in its “cosmic suit of armor”
North & South Poles
Radiation funneling down through to the Earth near the north pole
Aurora Borealis
Radiation funneling down through to the Earth near the south pole
Aurora Australis
Layers of the Earth (outer to inner)
- Crust (Continental & Oceanic)
- Mantle (Upper & Lower)
- Outer Core
- Inner Core
Layer made mostly of molten liquid iron and nickel
Outer Core - Liquid due to extremely high temperatures
Layer mostly made of iron and is solid
Inner Core - Hotter than other layers but solid due to extremely high pressures, which prevent the iron from melting
The 3 categories of rocks
- Sedimentary
- Metamorphic
- Igneous
Formed of pebbles, sand, shells and other X, these form by accumulating laters that form and fuse together over very long periods of time
Sedimentary Rocks
Soft by comparison to other rocks and can break apart easily. Examples include limestone, shale, coal, and sandstone
Sedimentary Rocks
Formed below the Earth’s surface and created by intense heat and pressure
Metamorphic Rocks
Very hard rocks that often have ribbons of color from the different layers of various materials and minerals. Examples include slate and marble
Metamorphic Rocks
Formed by the hardening of molten magma from deep within the Earth as it cools. Includes lava that erupts from volcanoes
Igneous Rocks
Depending on how quickly it cools, this rock can either be shiny and smooth or bumpy and rough from gas bubbles erupting as it cooled more slowly. Examples include granite, pumice, basalt, and obsidian
Igneous Rocks
When the Earth’s plates move, one of three types of plate boundaries occurs:
- Transform
- Divergent
- Convergent
Boundaries that occur when two plates slide past each other, which neither created nor destroys plate material
Transform Boundaries
Boundaries that occur when two plates move away from each other, which creates new plate material
Divergent Boundaries
Boundaries that occur when two plates move toward each other, which destroys existing plate material
Convergent
Earthquakes occur along ____ ____ (also called ____ ____), which are mostly found at transform plate boundaries
Fault Lines (also called Fault Zones)
The Richter Scale starts at 1 and increases by a power of __ to each subsequent number
10 (i.e., a score of 2 is 10x more powerful than a score of 1 and a score of 3 is 100x more powerful than a score of 1)
Used by scientists to better study and understand the history of the Earth and events of life and organisms that took place at certain times
Geologic Time Scale
Geologic Time Scale is measured by studying different strata of the Earth’s crust for ____, ____ __ ____, and ____ ____ (__ ____ __ ____ ____)
Fossils, types of rocks, and other indicators (of events in Earth’s history)
Approximate age of the Earth
4.5 Billion Years Old
Approximately when life on Earth first appeared
3.5 Billion Years Ago
Time that ended approximately 542 million years ago (cannot be defined for certain)
Precambrian Time
About 90% of Earth’s history occured in this time
Precambrian Time
Era that began 542 million years ago and lasted about 291 million years. Sea-life and other reptile life started during this period
Paleozoic Era
Era that began 251 million years ago and lasted about 186 million years. This was the age of reptiles, when dinosaurs lived
Mesozoic Era
Era that began 66 million years ago and includes the geological present time. This is the age of mammals, including homo sapiens
Cenozoic Era
