EARTH SCIENCE Flashcards
AGE OF EARTH
4.543 billion years old
a collective layer of gas that envelopes the Earth.
Atmosphere
Earth’s four major spheres
Atmosphere
Hydrosphere
Biosphere
Geosphere
(1) It shields the Earth and its inhabitants from harmful ultraviolet (UV) radiation from the Sun;
(2) it maintains the warmth of the Earth’s surface; and
(3) it contains all of the essential gases needed to support life.
Atmosphere
refers to the bodies of water consisting of freely flowing bodies of water found on the surface of the Earth
Hydrosphere
refers to the narrow band on the Earth’s surface where all biological life resides.
Biosphere
This sphere covers nearly 71% of the Earth’s surface.
Hydrosphere
the largest out of all the spheres, extending from the surface of the Earth down to its center.
Geosphere
Layers of Earth Based on Compositional Differences
Crust
Mantle
Core
This is the thinnest and outermost layer of the Earth.
Crust
two types of crust
the continental and oceanic crust.
younger and denser type of crust.
oceanic crust.
comprises most of the Earth’s volume
Mantle
The boundary between the crust and mantle
Mohorovičić discontinuity
core begins at the mantle-core boundary
Gutenberg discontinuity
divided into the upper and lower mantle, separated by
Repetti discontinuity.
its composition comprises a Fe-Ni (iron and nickel) alloy.
Core
Layers of Earth Based on Physical Properties
Lithosphere
Asthenosphere
Mesosphere
Outer Core
Inner Core
thick and brittle layer comprising the entire crust and uppermost layer of the upper mantle.
Lithosphere
Contrary to popular belief, it is not a “sea of molten rock.” The upper mantle comprises an Mg- and Fe-rich rock called
peridotite.
mechanically weak layer consisting of the lower portion of the upper mantle, extending to 660 km.
Asthenosphere
-comprised of the lower mantle
-is much stronger and flows with more resistance. Because of the immense pressure from the overlying layers, the strength of this layer increases with depth.
Mesosphere
The dominant rock type in this layer (Mesosphere) is a silicate rock called
perovskite.
Layer the only one made out of liquid
Outer Core
Core’s flow of liquid metals is responsible for the
Earth’s magnetic field
The outer-inner core boundary is also known as
Lehmann discontinuity.
To be considered a mineral:
Naturally-occurring
Inorganic
Homogeneous solid
Has definite chemical composition
Ordered crystalline structure
It refers to the wavelengths of light reflected by the minerals. While it can be tempting to identify a mineral based on its-, it is the least valuable property because many minerals can occur in different colors.
Color
It describes how light is reflected from the mineral’s surface.
Luster
This refers to the shape of each crystal or an aggregate of crystals.
Crystal Habit or Shape.
his is the color of the mineral when it is powdered.
Streak
This refers to how resistant a mineral is to scratching.
Hardness
refers to the tendency of a mineral to break along preferred planes called zones of weakness.
Cleavage or Fracture
This refers to the ratio between a mineral’s weight and the weight of a specific volume of water
Density or Specific Gravity
This describes how well a mineral handles stress, such as breaking, crushing, bending, or tearing.
Tenacity
This refers to how well light travels through a mineral.
Diaphaneity
This describes the magnetic property of a mineral
Magnetism
This describes a mineral’s reaction to a strong acid
Effervescence
Geologist licking rocks
Odor and Taste
-most common mineral group
-most abundant blocks
silicates
less abundant mineral group
non-silicates
are formed when molten material cools and solidifies.
Igneous Rocks
When igneous rocks form below the surface of the Earth
intrusive igneous or plutonic rocks
When igneous rocks form on the surface
extrusive igneous or volcanic rocks.
are formed from loose material called sediments that have been eroded in weathering and then buried and compacted in a process called diagenesis.
Sedimentary Rocks
are classified based on the characteristics of their clasts, such as size, angularity/roundedness, and sorting.
Clastic Sedimentary Rocks
Chemical sedimentary rocks are formed when water evaporates, leaving behind dissolved minerals. Common examples include halite or rock salt, gypsum, flint, chert, travertine, umber, and limestone rocks.
Non-clastic Sedimentary Rocks
When a rock is subjected to certain chemical (addition or removal of chemicals) or physical (change in temperature or pressure) processes that alter its chemical composition, mineralogy, and/or texture
Metamorphic Rocks
Type of metamorphic tock that is a rock is the result of deformation
foliated rocks.
Type of metamorphic rock usually develop in environments where deformation is minimal and other factors, such as chemically-active fluids, play a larger part in altering the rock.
Nonfoliated rocks
geological process in which earth materials are weathered and transported
Erosion
Land and water forms in this environment can be found on land and usually involve freshwater.
Terrestrial Environments
represent the interface between land and sea. It is here where freshwater meets with seawater.
Transitional Environments
These environments can be found in the open waters, from the shallow depths to the deepest portions of the ocean.
Marine Environments
branch of geology that studies rock layers, beds, or strata
Stratigraphy
the layers on the bottom are the oldest, while the layers above are younger.
Law of Superposition
Each stratum extends laterally until it encounters a barrier or obstacle.
Law of Lateral Continuity
Strata are deposited horizontally.
Law of Original Horizontality