2009 Final Exam Flashcards
What are the characteristics of a terrestrial planet?
Rocky, composed of carbon dioxide and nitrogen.
What is the difference between a rock and a mineral?
- A rock is an aggregate of minerals
- A mineral is a naturally occurring, inorganic crystalline structure with definite physical and chemical properties.
The earth formed _____ billion years ago?
4.6
The material in the Earth’s inner core is _____ while the outer core is _____.
- Solid
- Liquid
Which of the Following statements about a scientific theory is not true?
a. It is an explanation for some natural phenomena
b. It has a large body of supporting knowledge
c. It is testable
d. It is a conjecture or guess
e. None of the above
d. It is a conjecture or guess
The zone between the core and the crust is the:
a. innsersphere
b. lithosphere
c. mantle
d. convection center
e. molten zone
c. mantle
The ocean crust is composed mostly of:
a. granite
b. periodotite
c. basalt
d. sial
e. gneiss
c. basalt
True or False: In the 19th century, the geologic time scale was based primarily on sequence of fossils in the rock record.
True
True or False: The Principle of Uniformitarianism is based on the idea that modern processes have operated throughout geologic time.
True
What were the major lines of evidence for continental drift as presented by Wegener in the early 20th century?
- Continents fit together like a puzzle
- Similar plants and fossils were found on different continents
- Similar rock sequences and mountain ranges on different continents.
What was the principle reason why Wegener’s theory of continental drift was rejected?
He didn’t have a plausible mechanism to explain the movement.
Briefly explain the Wilson Cycle (also called the supercontinent cycle).
The cycle opening and closing ocean basins by the movement of the Earth’s plates.
How are hotspots used for determining the absolute motions of plates?
Hotspots appear to be fixed in place, so they can be used as a reference frame. If the age of the basalt and its distance from the hot spot is determined then the rate of movement of that rock or island can be calculated.
What was the name of the group of fossils that was considered as evidence for the supercontinent of Gondwana?
a. Glossaurus
b. Pecopteris
c. Neuropteris
d. Glossopteris
e. Messopteris
d. Glossopteris
The first person to suggest that all of the continents had originally been joined together as the supercontinent Pangaea was:
a. Alexander du Toit, 1937
b. Frank Taylor, 1910
c. Alfred Wegener, 1912
d. Neil O’Donnell, 1995
e. Snider Pelligrini, 1858
f. Harry Hess, 1962
c. Alfred Wegener
If the continents were once joined together, rocks and mountain ranges on the margins of each should have:
a. formed under the same conditions
b. formed under the same sequence
c. formed at the same time
d. the same structural trends and forces
e. all of the above
f. none of the above
g. A & C only
h. B & D only
e. all of the above
True or False: Changes in the Earth’s magnetic field have occured throughout geologic time and these are called magnetic reversals.
True
True or False: Hot spots move with continental plates.
False
True or False: The west coast of South America is a convergent boundary.
True
How do a rock and a mineral differ?
- A rock is an aggregate of minerals
- A mineral is a naturally occurring, inorganic crystalline solid with definite physical and chemical properties
Give an example of a native element.
- Gold
- Silver
- Copper
- Diamond
- Graphite
What is a simple chemical test which will distinguish calcite from non-carbonate minerals?
Calcite will effervesce in hydrochloric acid, other non-carbonate minerals will not.
What is a simple chemical test which will distinguish calcite from non-carbonate minerals?
Calcite will effervesce in hydrochloric acid, other non-carbonate minerals will not.
What is the most distinctive property of the mineral halite?
Its salty taste
Diamond and graphite are two minerals with the same chemical composition, but extremely different physical properties. Why is this?
They have different crystalline structures.
In the _____ type of chemical bonding, electrons are shared between adjacent atoms.
covalent
The basic building block of silicate minerals is the silica _____.
tetrahendron
The hardest, most chemically inert common rock-forming mineral is _____.
quartz
Cleavage is defined as:
a. planes of fracture resulting from weak bonds
b. smooth, flat reflective surfaces
c. surfaces of smooth, curved fracture
d. planes of fracture resulting from strong bonds
e. none of the above
a. planes of fracture resulting from weak bonds
An example of a material which has been both a resource and a reserve depending on abundance, economic conditions, and mining technology is:
a. platinum
b. gold
c. petroleum
d. iron
e. all of the above
f. none of the above
e. all of the above
True or False: Minerals may have chemical compositions that vary within a range.
True
True or False: Noble gases are chemically inert because their outer electron shell is filled.
True
How does lava differ from magma?
Lava is magma at Earth’s surface, and has lost gases and volatiles.
What does a phaneritic texture tell about the history of an igneous rock?
The magma cooled slowly and has a coarse texture.
What does a porphyritic texture tell about the history of an igneous rock?
The magma cooled at two rates. First slowly, then more rapidly. Creating different textures within the rock.
How does a dike differ from a sill?
A dike is discordant, a sill is concordant.
How does a dike differ from a sill?
A dike is discordant, a sill is concordant.
By the process of _____ the composition of magma can be changed when it comes into contact with country rock.
assimilation
An igneous rock in which large mineral grains called _____ are suspended in a finely crystalline groundmass is called a _____.
- Phenocrysts
- Porphyry
Basalt and gabbro are compositional equivalents which means that they are made up of the same _____ minerals but have different _____.
- minerals
- textures
The largest intrusive bodies are called _____ and, by definition, they must have at least _____ square kilometers of surface area.
- Batholiths
- 100
A dark coloured igneous rock with no visible crystals cooled:
a. slowly in a magma chamber
b. quickly in a magma chamber
c. slowly on the Earth’s surface
d. quickly on the Earth’s surface
e. none of the above
b. quickly in a magma chamber
Aphanitic, phaneritic, and porphyritic are textual terms that:
a. refer to fine-grained, course grained and mixed grained crystal sizes, respectively.
b. refer to formation by slow cooling, fast cooling, and mixed cooling rates, respectively.
c. are indicative of volcanic, plutonic and mixed plutonic-volcanic origins, respectively.
d. A and C
e. A, B, and C
d. A and C
True or False: Bowen’s Reaction Series explains the order of mineral formation with decreasing temperature.
True
True or False: Bowen’s Reaction Series explains why Si-rich minerals are the last to crystallize from magma.
True.
Match the aphanitic rock type with its phaneritic intrusive compositional equivalent below:
A. rhyolite
B. basalt
C. ansesite
___ diorite
___ granite
___ gabbro
C –> Diorite
A –> Granite
B –> Gabbro
How is volcanism destructive? What are two reasons that it is primarily a constructive process?
- Some volcanic eruptions are explosive and they blow a lot of material outward.
- Volcanism also builds up material, including at the volcanoes and lava flows. This creates new islands and new sea floor.
What is a lahar?
A destructive mud flow on the slopes of a volcano.
Which magma type usually erupts from fissures?
Basalt
According to plate tectonic theory, why are there volcanoes in Hawaii?
The volcanoes formed over a hot spot.
The eruption that buried the city of Pompeii, Italy in 79A.D. was that of Mount _____, which prior to the eruption had been quiet for at least _____ years.
- Vesuvivus
- ???
The one place on Earth where mid-ocean ridge volcanism occurs above sea level is _____.
Ice Land
Volcanism occurs along the following two types of plate boundaries: _____ and _____.
- Convergent
- Divergent
An example of a shield volcano is:
a. Kilauea
b. Mount St. Helens
c. Mount Shasta
d. Mount Mazama
e. Fujiyama
a. Kilauea
True or False: Earth is the only body in our solar system that is volcanically active?
False
True or False: Lava flows are the greatest hazard of volcanoes.
False
True or False: a nuee ardente may travel at speeds as high as 100KM per hour.
True
What are index minerals, as the term is applied to metamorphic rocks?
The occur at certain temperatures and depths and can be used to tell where and when a metamorphic rock formed.
What is a metamorphic facies?
A set of metamorphic mineral assemblages that were formed under similar pressures and temperatures.
What are some examples of foliated metamorphic rocks?
- Gneiss
- Phylite
- Schist
The concentric zones surrounding an igneous intrusion, and in which contact metamorphism has taken place are called _____.
Aureoles
The type of metamorphism that occurs over large areas, commonly at convergent plate margins, and is responsible for the production of most metamorphic rocks is _____.
Regional
Metamorhpism takes place:
a. in the liquid state, melted by contact with magma.
b. in the solid state with or without fluid activity.
c. only at great depth.
d. A and C
e. all of the above
b. in the solid state with or without fluid activity.
The two most important sources of heat for metamorphism are:
a. intrusive magma bodies and deep burial
b. intrusive magma bodies and heat from the core
c. deep burial and volcanism
d. radioactive decay and volcanism
e. radioactive decay and deep burial
a. intrusive magma bodies and deep burial
True or False: Metamorphic rocks are very common in the crystalline basement rocks of shields.
True
True or False: Metamorphic rocks have formed throughout all geologic periods.
True
What is a cone of depression, where is it found, and what causes it? Why can large cones of depression be a serious problem?
Water being removed from an aquifer faster than the rate of replenishment. This can drain and dry water tables which are a source of fresh water.
What is a cone of depression, where is it found, and what causes it? Why can large cones of depression be a serious problem?
Water being removed from an aquifer faster than the rate of replenishment. This can drain and dry water tables which are a source of fresh water.
How are stalactites different from stalagmites? Why do they typically form in pairs and often merge to form a column?
Stalactites hang from the ceiling, stalagmites grow upward from the ground. They form in paris because the drippings from the stalactites cause the stalagmites to grow underneath them, and they eventually meet to form a column.
Under what conditions will an artesian well flow freely at the surface?
When the pressure surface is above ground level, the artesian well will flow freely.
How are sinkholes formed?
When soluble bedrock can be dissolved by water, the ground collapses and creates a depression/sinkhole in the ground.
The major source of the water stored as groundwater is _____.
precipitation
The percentage of open space within a rock or sediment is known as its _____.
porosity
A permeable layer that transports water is called an _____.
aquifer