Question 1

Which type of microfossils have a tooth- like shape made of apatite, are a mouth part of an extinct swimming eel- like chordate, and are useful index fossils for the Paleozoic through Triassic?

Accepted Answer

Conodonts are known for their tooth-like shape made of apatite, and they are recognized as parts of the feeding apparatus of an extinct group of eel-like chordates. They serve as valuable index fossils for the Paleozoic through Triassic periods.

Question 2

The ________is the idea or concept that ancient life forms succeeded each other in a definite, evolutionary pattern and that the contained assemblage of fossils can uniquely determine geologic ages of strata.

Accepted Answer

The principle of fossil succession states that sedimentary rock layers contain fossilized flora and fauna, which succeed each other vertically in a specific, reliable order that can be identified over wide horizontal distances. This principle allows geologists to determine the ages of strata by examining the fossils contained within them.

Question 3

The rare element iridium has been implicated in which "ancient health" crisis?

Accepted Answer

Iridium is rare on Earth's crust but abundant in meteorites. The high levels of iridium found in the layer of sediment dating from the end of the Cretaceous Period support the theory that a massive meteorite impact contributed to the extinction of the dinosaurs.

Question 4

Which of the following best characterizes an angular unconformity?

Accepted Answer

An angular unconformity is characterized by an orientation where the strata below the unconformity are tilted or folded and the strata above are deposited in a horizontal or nearly horizontal position, indicating a period of deformation followed by erosion and then deposition.

Question 5

Which of the following is the name of an eon in the geologic time scale?

Accepted Answer

The Phanerozoic is the name of an eon in the geologic time scale, encompassing the current era of visible, complex life on Earth.

Question 6

Which of the following statements is true, concerning sedimentary strata separated by a disconformity?

Accepted Answer

A disconformity in geology indicates a period of erosion or non-deposition separating younger from older sedimentary strata, with both sets of layers being parallel to each other. This represents a hiatus in the geological record but does not imply tilting or deformation of the layers.

Question 7

The Phanerozoic Eon comprises approximately the ________of geologic time.

Accepted Answer

The Phanerozoic Eon represents the last 15% of Earth's geologic time, covering roughly the last 541 million years, where abundant animal and plant life has existed.

Question 8

What is the age of the Earth accepted by most scientists today?

Accepted Answer

The age of the Earth is widely accepted by scientists to be about 4.6 billion years, based on radiometric age dating of meteorite material and is consistent with the ages of the oldest-known terrestrial and lunar samples.

Question 9

In radiometric dating, an unstable radioactive isotope is called_______ .

Accepted Answer

In radiometric dating, the unstable radioactive isotope that decays over time is referred to as the "parent" isotope. This parent isotope gradually transforms into a stable "daughter" isotope, a process that is used to determine the age of rocks and organic materials.

Question 10

Which organisms were free swimmers and found in a great variety of Paleozoic and Mesozoic marine habitats?

Accepted Answer

Ammonoids and conodonts were marine organisms that thrived during the Paleozoic and Mesozoic eras. Ammonoids, a group of extinct marine mollusks, were notable for their spiral shells and are often used as index fossils. Conodonts, on the other hand, were eel-like creatures with tooth-like elements, playing a significant role in understanding marine paleoenvironments. Both were free-swimming organisms found in a variety of marine habitats during their respective eras.

Question 11

The ratio of radioactive parent to stable daughter atoms in a mineral is measured as 1:3. How many half- lives have elapsed since the mineral grain formed, assuming that only parent atoms were present when it crystallized?

Accepted Answer

After one half-life, the ratio of parent to daughter atoms would be 1:1. After two half-lives, the parent atoms would have halved again, resulting in a 1:3 ratio of parent to daughter atoms, indicating that two half-lives have elapsed.

Question 12

Of an original amount of radioactive parent isotope, 25% remains and 75% has decayed. How many half- lives have elapsed?

Accepted Answer

After one half-life, 50% of the original amount would remain. After two half-lives, this amount would halve again, leaving 25% of the original amount.

Question 13

Which of the following denotes the investigative process by which geologists identify and match sedimentary strata and other rocks of the same ages in different areas?

Accepted Answer

Correlation is the process used by geologists to match rocks of the same age in different locations, helping to piece together the geological history of an area.

Question 14

Visualize (or draw) five, horizontal, sedimentary strata as exposed in a cliff or canyon wall identified by consecutive numbers, 1 being the lowest bed and 5 being the highest. Which of the following statements concerning the strata are true?

Accepted Answer

In undisturbed sedimentary layers, the law of superposition states that the oldest layers are at the bottom. Thus, beds 1 and 3 are older than bed 4.

Question 15

Which of the following does not have at least one, very long- lived, natural, radioactive isotope?

Accepted Answer

Calcium (Ca) does not have a very long-lived, natural, radioactive isotope. Rubidium, potassium, and thorium all have naturally occurring isotopes with very long half-lives, such as Rb-87, K-40, and Th-232, respectively.

Question 16

Assume that human recorded history can be stretched back to 4600 years before the present. This is approximately what fraction of geologic time?

Accepted Answer

The Earth is approximately 4.6 billion years old. If human recorded history is about 4600 years, then it represents 1/1,000,000th of the Earth's history, making one millionth the correct fraction.

Question 17

Working on fossiliferous strata in the mountains of western Italy,____ was first to work out____which is the fundamental way geologists know which bed is older in any sedimentary
sequence

Accepted Answer

Nicolaus Steno was the first to articulate the law of superposition, which states that in any undeformed sequence of sedimentary rocks, each layer is older than the one above and younger than the one below. This principle is a foundational concept for determining the relative ages of rock layers.

Question 18

At the end of the Cretaceous (K/T boundary) what unusual geologic phenomenon occurred that has been linked to mass extinction and the end of the dinosaurs?

Accepted Answer

The end of the Cretaceous period is marked by a significant event where a meteor impact occurred on the Yucatan Peninsula, creating the Chicxulub crater. This event is widely accepted as a major cause of the mass extinction that led to the demise of the dinosaurs and many other species.

Question 19

A few rare times in earth history the majority of life forms disappeared "clearing the ecologic slate" for new ones. When this happens it is called_________ .

Accepted Answer

Mass extinctions are significant events in Earth's history when a large percentage of species die out in a relatively short period of time, allowing new species to evolve and fill the vacated ecological niches.

Question 20

The half- life of carbon- 14 is about 5730 years. Assume that a sample of charcoal formed by burning wood that lived 25,000 years ago. How much of the original carbon- 14 would remain today?

Accepted Answer

The half-life of carbon-14 is 5730 years. After 25,000 years, there would be 1/16 of the original carbon-14 remaining.

Quiz 19: Shorelines

Which type of microfossils have a tooth- like shape made of apatite, are a mouth part of an extinct swimming eel- like chordate, and are useful index fossils for the Paleozoic through Triassic?

The ________is the idea or concept that ancient life forms succeeded each other in a definite, evolutionary pattern and that the contained assemblage of fossils can uniquely determine geologic ages of strata.

The rare element iridium has been implicated in which "ancient health" crisis?

Which of the following best characterizes an angular unconformity?

Which of the following is the name of an eon in the geologic time scale?

Which of the following statements is true, concerning sedimentary strata separated by a disconformity?

The Phanerozoic Eon comprises approximately the ________of geologic time.

What is the age of the Earth accepted by most scientists today?

In radiometric dating, an unstable radioactive isotope is called_______ .

Which organisms were free swimmers and found in a great variety of Paleozoic and Mesozoic marine habitats?

The ratio of radioactive parent to stable daughter atoms in a mineral is measured as 1:3. How many half- lives have elapsed since the mineral grain formed, assuming that only parent atoms were present when it crystallized?

Of an original amount of radioactive parent isotope, 25% remains and 75% has decayed. How many half- lives have elapsed?

Which of the following denotes the investigative process by which geologists identify and match sedimentary strata and other rocks of the same ages in different areas?

Visualize (or draw) five, horizontal, sedimentary strata as exposed in a cliff or canyon wall identified by consecutive numbers, 1 being the lowest bed and 5 being the highest. Which of the following statements concerning the strata are true?

Which of the following does not have at least one, very long- lived, natural, radioactive isotope?

Assume that human recorded history can be stretched back to 4600 years before the present. This is approximately what fraction of geologic time?

Working on fossiliferous strata in the mountains of western Italy, was first to work outwhich is the fundamental way geologists know which bed is older in any sedimentary sequence

At the end of the Cretaceous (K/T boundary) what unusual geologic phenomenon occurred that has been linked to mass extinction and the end of the dinosaurs?

A few rare times in earth history the majority of life forms disappeared "clearing the ecologic slate" for new ones. When this happens it is called_________ .

The half- life of carbon- 14 is about 5730 years. Assume that a sample of charcoal formed by burning wood that lived 25,000 years ago. How much of the original carbon- 14 would remain today?

Quiz 19: Shorelines

Which type of microfossils have a tooth- like shape made of apatite, are a mouth part of an extinct swimming eel- like chordate, and are useful index fossils for the Paleozoic through Triassic?

The ________is the idea or concept that ancient life forms succeeded each other in a definite, evolutionary pattern and that the contained assemblage of fossils can uniquely determine geologic ages of strata.

The rare element iridium has been implicated in which "ancient health" crisis?

Which of the following best characterizes an angular unconformity?

Which of the following is the name of an eon in the geologic time scale?

Which of the following statements is true, concerning sedimentary strata separated by a disconformity?

The Phanerozoic Eon comprises approximately the ________of geologic time.

What is the age of the Earth accepted by most scientists today?

In radiometric dating, an unstable radioactive isotope is called_______ .

Which organisms were free swimmers and found in a great variety of Paleozoic and Mesozoic marine habitats?

The ratio of radioactive parent to stable daughter atoms in a mineral is measured as 1:3. How many half- lives have elapsed since the mineral grain formed, assuming that only parent atoms were present when it crystallized?

Of an original amount of radioactive parent isotope, 25% remains and 75% has decayed. How many half- lives have elapsed?

Which of the following denotes the investigative process by which geologists identify and match sedimentary strata and other rocks of the same ages in different areas?

Visualize (or draw) five, horizontal, sedimentary strata as exposed in a cliff or canyon wall identified by consecutive numbers, 1 being the lowest bed and 5 being the highest. Which of the following statements concerning the strata are true?

Which of the following does not have at least one, very long- lived, natural, radioactive isotope?

Assume that human recorded history can be stretched back to 4600 years before the present. This is approximately what fraction of geologic time?

Working on fossiliferous strata in the mountains of western Italy,____ was first to work out____which is the fundamental way geologists know which bed is older in any sedimentary sequence

At the end of the Cretaceous (K/T boundary) what unusual geologic phenomenon occurred that has been linked to mass extinction and the end of the dinosaurs?

A few rare times in earth history the majority of life forms disappeared "clearing the ecologic slate" for new ones. When this happens it is called_________ .

The half- life of carbon- 14 is about 5730 years. Assume that a sample of charcoal formed by burning wood that lived 25,000 years ago. How much of the original carbon- 14 would remain today?

Working on fossiliferous strata in the mountains of western Italy, was first to work outwhich is the fundamental way geologists know which bed is older in any sedimentary sequence