9.3: Questions

Question 1 What was the main idea behind the doctrine of catastrophism?
Earth's landscapes were shaped by slow and gradual processes
Earth's landscapes were fashioned primarily by great catastrophes
Earth's age was estimated to be over six thousand years
Earth's processes were driven by human activities

Question 2 What belief or assumption was the doctrine of catastrophism in geology based on?
The history of Earth was long
The history of Earth was short
The history of Earth was uniform
The history of Earth was varied

Question 3 What was the primary goal of the doctrine of catastrophism in relation to the Earth's time scale?
To extend the Earth's time scale to millions of years
To prove that the Earth is older than six thousand years
To disprove the concept of gradual geological changes
To fit the rate of Earth's processes into a time scale of less than six thousand years

Question 4 Theory of the Earth was the work of
Charles Darwin
Albert Einstein
Isaac Newton
James Hutton

Question 5 What new idea or principle did Theory of the Earth introduce in geology?
Uniformitarianism
Catastrophism
Mutualism
Complexity

Question 6 According to the principle of uniformitarianism, what is the relationship between present-day processes and the geologic past?
Present-day processes are completely different from those in the geologic past
Present-day processes are similar to those in the geologic past, but operate at a slower rate
The physical, chemical, and biological processes that operate today have also operated in the geologic past
Present-day processes have no bearing on our understanding of the geologic past

Question 7 What is the common statement that reflects the idea of uniformitarianism?
The future is the key to the past
The present is the key to the past
The present is the key to the future
The past is the key to the present

Question 8 What is necessary to understand ancient rocks, according to the principle of uniformitarianism?
To understand present-day processes and their results
To understand the catastrophes that shaped the Earth
To estimate the exact age of the Earth
To study only the rocks themselves

Question 9 What is the primary goal of scientists when seeking a numerical date for an event?
To determine the exact dates of events
To identify the type of rocks present
To describe the geological processes involved
To estimate the likelihood of future events

Question 10 What information can be obtained by placing rocks in their proper sequence of formation?
The actual number of years since the rocks formed
The types of fossils present in the rocks
The relative order of formation, but not the time elapsed
The chemical composition of the rocks

Question 11 What is a limitation of using principles of relative dating to analyze geological events?
They can only be used to date recent events
They cannot indicate whether one event followed another
They cannot provide information about the time elapsed since an event occurred
They require specialized equipment to interpret the results

Question 12 According to the principle of superposition, what can be said about the age of a bed of sedimentary rock?
It is older than the bed above it and younger than the bed below it
It is younger than the bed above it and older than the bed below it
It is the same age as the bed above it and the bed below it
It is impossible to determine its age relative to the beds above and below it

Question 13 What does the principle of original horizontality state about the deposition of sedimentary layers?
They are generally deposited in a horizontal position
They are always deposited in a vertical position
They are deposited at a 45-degree angle
They are deposited in a random orientation

Question 14 According to the principle of lateral continuity, what can be inferred about identical strata across a canyon?
They once spanned the canyon
They were never connected
They are of different ages
They are of different types of sediment

Question 15 What is the main idea behind the principle of cross-cutting relationships?
Geologic features that cut across rocks must form after the rocks they cut through
Geologic features that cut across rocks must form before the rocks they cut through
Geologic features that cut across rocks are the same age as the rocks they cut through
Geologic features that cut across rocks are unrelated to the rocks they cut through

Question 16 What type of geologic feature provides an example of the principle of cross-cutting relationships?
Dikes
Folds
Faults
Strata

Question 17 If rock layers are observed to be folded or tilted at a steep angle, what can be inferred about their history?
They must have been moved into that position by crustal disturbances sometime after their deposition
They were deposited in that position
They have always been in that position
They are not sedimentary rocks

Question 18 According to the principle of inclusion, what can be said about the relative age of two rocks when one includes the other?
The inclusions are older
The rock units are the same age
The age of the rock units cannot be determined
The inclusions are younger

Question 19 When magma intrudes into surrounding rock and incorporates blocks of that rock, what is true?
The magma is younger than the incorporated rock blocks
The magma and the rock blocks are the same age
The age relationship between the magma and the rock blocks cannot be determined
The incorporated rock blocks are younger than the magma

Question 20 According to the principle of inclusions, what must have happened for blocks of surrounding rock to be incorporated into magma?
The magma must have solidified first
The surrounding rock must have been dislodged and incorporated into the magma
The magma must have been pushed away by the surrounding rock
The surrounding rock must have melted into the magma

Question 21 What term is used to describe layers of rock that have been deposited essentially without interruption?
Conformable
Unconformable
Disconformable
Nonconformable

Question 22 Which type of unconformity involves younger sedimentary strata overlying older metamorphic or intrusive igneous rocks?
Nonconformity
Angular unconformity
Disconformity
Conformity

Question 23 What is the primary process that occurs during the time represented by an unconformity?
Deposition
Erosion
Metamorphism
Igneous activity

Question 24 An angular unconformity is characterized by which of the following features?
Tilted or folded sedimentary rocks overlain by younger, more flat-lying strata
A gap in the rock record with no erosion or deposition
Younger sedimentary strata overlying older sedimentary rock
Older metamorphic rocks overlain by younger sedimentary strata

Question 25 What happens to the sedimentary layers when sea level falls or the land rises during the formation of a disconformity?
They are eroded away
They are uplifted and metamorphosed
They are deposited at a faster rate
They remain unchanged

Question 26 What is the significance of an unconformity in the rock record?
It represents a long period of uninterrupted deposition
It indicates a period of deformation, erosion, or change in deposition
It is a gap in the rock record with no geological significance
It marks the beginning of a new geological era

Question 27 What is the term used to describe the scientific study of fossils?
Paleontology
Geology
Biology
Archaeology

Question 28 What process occurs when mineral-rich groundwater fills pores and empty spaces in porous tissue such as wood?
Permineralization
Sedimentation
Erosion
Deposition

Question 29 What is the result of the transformation of wood through the process of permineralization with silica?
Chert
Sandstone
Shale
Limestone

Question 30 What is created when a structure such as a shell is buried in sediment and then dissolved by underground water?
Mold
Cast
Fossil
Petrified wood

Question 31 What is formed when hollow spaces left by molds are filled with mineral matter?
Casts
Molds
Fossils
Sedimentary rocks

Question 32 What is the principle that states fossil organisms succeed one another in a definite order?
Principle of fossil succession
Law of rock formation
Theory of geological time
Concept of stratigraphy

Question 33 What is the primary reason why index fossils are useful for correlating rocks of similar age in different regions?
They are widespread geographically and limited to a short span of geologic time
They are found only in rocks of a specific type
They are the most common type of fossil found in rocks
They can only be used to date rocks from the same continent

Question 34 What can be used to establish the age of a rock formation when it does not contain an index fossil?
A group of fossils, called a fossil assemblage
The color and texture of the rock
The location where the rock was found
The type of mineral composition of the rock

Question 35 Why fossil assemblage is more effective than a single index fossil for dating of rocks?
It provides a more precise age determination
It is faster and less expensive
It can only be used for rocks from the same region
It is limited to rocks from a specific geologic time period

Question 36 What is the primary method used to determine the age of rocks that contain unstable isotopes?
Radiometric dating
Geologic time scaling
Fossil record analysis
Seismic wave measurement

Question 37 Why is radiometric dating considered a reliable process for calculating the ages of rocks and minerals?
The rates of decay for many isotopes have been precisely measured and do not vary under Earth's physical condition
The process is based on the principles of gravity and magnetism
It is influenced by the Earth's atmospheric conditions
The method relies on visual observations of rock formations

Question 38 What describes the span of geologic time measured through changes in the nuclei of atoms?
Deep time
Geologic era
Fossil record
Earth's timeline

Question 39 What is the term used to describe the time required for half of the nuclei in a sample of a given unstable isotope to decay?
Half-life
Radioactive decay
Isotope ratio
Geologic time

Question 40 What is the primary reason why radiocarbon dating is suitable for dating relatively recent events?
The half-life of carbon-14 is only 5730 years
The half-life of carbon-14 is over 100,000 years
Radiocarbon dating can only be used on inorganic materials
Radiocarbon dating is not accurate for recent events

Question 41 What is the primary purpose of the geologic time scale in Earth's history?
To provide a meaningful time frame for arranging geologic events
To explain the formation of fossils
To describe the different types of rocks
To predict future geological events

Question 42 Which eon is characterized by the presence of abundant fossils and began about 541 million years ago?
Phanerozoic
Paleozoic
Mesozoic
Cenozoic

Question 43 How are eons divided in the geologic time scale?
Into eras
Into periods
Into epochs
Into fossils

Question 44 What is the significance of the names of the eras in the Phanerozoic eon?
They imply profound worldwide changes in life-forms
They describe the different types of rocks
They explain the formation of fossils
They predict future geological events

Question 45 What is the first period of the Paleozoic era?
Silurian
Ordovician
Devonian
Cambrian