Earth Science S1 Midterm Review
How does Relative Dating differ from Numerical Dating?
Relative dating involves dating based off of the rock layer, as well as any known items found at a similar level. Meanwhile, numerical dating allows us to use the number of half-lives that a rock has experienced in order to accurately date it
Which lava type - Basalt, Andesite, Rhyolite - is most viscous?
Rhyolite
What lava type is associated with the Yellowstone eruptions?
Rhyolitic
Which lava type - Basalt, Andesite, or Rhyolite - has the most silica?
Rhyolitic
What is the function of the Asthenosphere in Plate Tectonic Theory?
The asthenosphere has a fluid-like properties with high viscosity that the crust rides on.
Where is the location (depths) of the Asthenosphere relative to the Earth's surface?
The asthenosphere is the denser, weaker layer beneath the lithospheric mantle. It lies between about 100 kilometers (62 miles) and 410 kilometers (255 miles) beneath Earth's surface.
Is the Asthenosphere rigid?
The asthenosphere is the semi-rigid part of the middle mantle that flows like hot asphalt under a heavy weight. The crust and the upper layer of the mantle together make up a zone of rigid, brittle rock called the Lithosphere.
What is uniformitarianism?
The belief that the Earth's past geological changes can be fully explained by current processes.
What is a volcanic vent?
The central vent or throat of the volcano where the magma erupts. Also fumaroles, where the gases vent out.
Where is the Lithosphere located with respect to the Crust and Mantle?
The lithosphere includes the crust (whether continental or oceanic) and the uppermost part of the upper mantle. It thins to a few kilometres at ocean spreading centres, thickens to about 100 - 150 km under the older parts of ocean basins, and is up to 250 - 300 km thick under continental shield areas.
Where is the location of the Asthenosphere relative to the Lithosphere?
The lithosphere is the hard and rigid uppermost part of the mantle and crust. The asthenosphere is the soft layer in the lower part of the mantle.
Why did many scientists not believe Alfred Wegener's ideas on Continental Drift?
The main reason that Wegener's hypothesis was not accepted was because he suggested no mechanism for moving the continents. He thought the force of Earth's spin was sufficient to cause continents to move, but geologists knew that rocks are too strong for this to be true.
How many cleavage directions exist for a mineral that cleaves in the shape of a cube?
Three cleavage directions
What drives lithospheric plates?
convection cells
Aleutian Islands
convergent
Himalayas
convergent
Japan
convergent
Plates being destroyed
convergent
Plates moving together
convergent
Subduction Zones
convergent
The strongest earthquakes
convergent
Trenches
convergent
Tsunami formation
convergent
Volcanic Island Arcs
convergent
What is Pillow lava and where is it found?
Typically forms at volcanoes at mid-ocean ridges or at oceanic hot-spot volcanoes, such as those that formed the Hawaiian Islands. Basalt forms the crust of all the ocean basins and is therefore the most common rock in the Earth's crust.
What are the most common components of volcanic gas?
Water Vapor, Carbon Dioxide, Sulfur Dioxide
In the rock cycle, what is weathering?
Weathering is the breaking down or dissolving of rocks and minerals on Earths surface. Once a rock has been broken down, a process called erosion transports the bits of rock and minerals away.
What characterizes a good Index Fossil?
Widespread geographically with a short time range
What is the principle of superposition?
Within a sequence of rock layers formed at Earth's surface, rock layers lower in the sequence are older.
What is an eruption column?
a cloud of super-heated ash and tephra suspended in gases emitted during an explosive volcanic eruption
What is a caldera?
a large depression formed when a volcano erupts and collapses.
What are vesicles?
a small cavity in an aphanitic or glassy igneous rock, formed by expansion of a bubble of gas or steam during solidification of the rock
What is fissure?
an elongate fracture or crack at the surface from which lava erupts.
East Africa
divergent
Iceland
divergent
Magma forming new ocean floor
divergent
Mid-Ocean Ridges
divergent
Plates being created
divergent
Plates moving away from each other
divergent
Sea-floor spreading
divergent
Rift Valleys
divergent boundaries
What is common to both glass and quartz? What is different?
glass has a random molecular structure, while quartz has a symmetrical molecular structure. Quartz can be subject to greater temperature and pressure as compared to glass. Both quartz and glass are utilized for electrical purposes; glass is an insulator, while quartz is a conductor.
What is Pumice composed of?
highly microvesicular glass pyroclastic with very thin, translucent bubble walls of extrusive igneous rock.
What is the composition of the outer core?
liquid iron and nickel
What makes lava more viscous?
more silica
What is a lahar flow?
mudflow or debris flow that originates on the slopes of a volcano.
Mauna Loa
shield volcano
What is the composition of the inner core?
solid iron and nickel
What is Pangaea?
the landmass that existed when all continents were joined, from about 300 to 200 million years ago.
In the Rock Cycle, what is Lithification?
the process by which clay, sand, and other sediments on the bottom of the ocean or other bodies of water are slowly compacted into rocks from the weight of overlying sediments.
Cleavage
the splitting of a mineral along smooth, flat surfaces
Ocean floor is neither created nor destroyed
transform
Offsets in Mid-Ocean Ridges
transform
Plates moving past each other
transform
San Andreas Fault
transform
What is the composition of a streak plate?
unglazed porcelain
What sizes are associated with volcanic, ash, cinders, and blocks?
Ash & Dust (< 2mm) Cinders (Lapilli) (2-64 mm) Blocks (>64 mm; hardened)
Which is capable of a taffy-like flow, the Lithosphere or Asthenosphere?
Asthenosphere
Which lava type - Basalt, Andesite, or Rhyolite - is the most common?
Basalt
Which type of lava - Basalt, Andesite, or Rhyolite - flows the fastest?
Basalt
What is the composition of the crust?
Basalt and granite
Which mineral will fizz in Hydrochloric Acid?
Calcite
What mountain range is associated with Mt. St. Helens?
Cascade Mountains
What did Catastrophism imply regarding the age of the earth?
Catastrophists believe great catastrophes primarily shaped the earth's landscapes. Mountains and Canyons resulted from sudden disasters produced by unknowable causes that no longer exist.
small volcanos
Cinder Cone Volcano
Pyroclastic Flows
Cinder cone Volcano
Which property of a mineral is the most variable?
Color
What tectonic boundary type is associated with the Cascade Volcanoes?
Convergent
How do cleavage surfaces differ from crystal faces?
Crystal faces are normally smooth, whereas cleavage planes, though also smooth, commonly are broken in a step-like fashion; Some crystal faces have fine grooves or ridges on their surfaces, whereas cleavage planes do not.
Red Sea
Divergent
What is the Principle of Fossil Succession?
Fossil organisms succeed one another in a definite and determinable order, and therefore any time period can be recognized by its fossil content.
What is common to both Diamonds and Graphite? What is different?
Graphite and diamond are two of the most interesting minerals. They are identical chemically - both are composed of carbon (C), but physically, they are very different. Minerals which have the same chemistry but different crystal structures are called polymorphs.
How did the geography of continental margins support the fit of continents according to Wegener?
How do the ages of the Hawaiian Islands support the movement of the Pacific Plate?
What tectonic plates are associated with Mt. St. Helens?
Juan de Fuca Plate and the North American Plate
How does temperature relate to a lava's viscosity?
Lower temperature magmas have higher viscosity than higher temperature magmas (viscosity decreases with increasing temperature of the magma).
In the Rock Cycle, what is Crystallization?
Magma cools either underground or on the surface and hardens into an igneous rock. As the magma cools, different crystals form at different temperatures, undergoing crystallization.
Name two basic types of luster.
Metallic and Non-Metallic
Specific gravity of water
10
specific gravity of gold
20
When did the Mesozoic era begin?
250 million years ago
When did the Triassic period begin?
251 million years ago
Specific Gravity of quartz
265
What is the hardness of Calcite?
3
What is the hardness of a copper penny
3
What is the age of the Earth?
4.6 billion years old
What is the hardness of glass
5.5
What is the hardness of Feldspar?
6
When did the Cenozoic era begin?
65 million years ago
What is the hardness of quartz?
7
Specific Gravity of Galena
75
Does a mineral have to have a specific Chemical Composition?
A Mineral is defined as an inorganic, naturally occurring, homogenous solid, with a definite chemical composition, and ordered (crystalline) atomic structures.
With what eruption are plaster casts of victims associated?
Mount Vesuvius
Can a mineral be grown in the lab?
No
Do all minerals possess cleavage to some degree?
No
Is glass a mineral? (Why or why not?)
No
What is the composition of the mantle?
Oxygen, silicon, and magnesium
What is the difference between Aa and Pahoehoe lava?
Pahoehoe is lava that in solidified form is characterized by a smooth, billowy, or ropy surface, while aa is lava that has a rough, jagged, spiny, and generally clinkery surface.
What is the Principle of Original Horizontality?
Sedimentary rocks are close to horizontal when deposited.
Non-viscous lava.
Shield Volcano
What is the definition of Specific Gravity?
Specific Gravity - the weight of a mineral compared to an equal volume of water