Geological Discoveries - TOEFL iBT® Reading Practice Test with Answer Key

Getting ready for the TOEFL test becomes notably simpler when you make use of tools like practice tests, a highly effective approach for comprehensive preparation. Participating in simulated evaluations, particularly for the TOEFL Reading segment, will aid in familiarizing you with the exam's format.

Let us explore the TOEFL Reading Practice Test Paper centered on the topic 'Geological Discoveries’, aiming to gain a better grasp of areas needing enhancement and to assist you in achieving your desired score!

Reading Instructions

• You have 15 minutes to read the following passage and answer all 9 questions related to it.  
• Most questions are worth 1 point, but the last question is worth more. The directions indicate how many points you will receive for that specific question. 
• The specific section/paragraphs have been provided again with the question for ease of understanding and quick solution.
• Some questions include a word or phrase that is highlighted in the question as well as in the paragraph for quick reference. 

In 1970, geologists Kenneth J. Hsu and William B. F. Ryan conducted research aboard the oceanographic research vessel Glomar Challenger. The expedition aimed to investigate the Mediterranean's seafloor and address inquiries regarding its geological past. One inquiry focused on the sudden transformation in the Mediterranean's invertebrate fauna around 6 million years ago. While many older organisms faced near extinction, a few resilient species persisted. Some of these species migrated to the Atlantic, only to return later with new companions. What factors precipitated these near-extinction events and subsequent migrations?

Another objective for the scientists aboard the Glomar Challenger was to ascertain the source of the dome-shaped formations hidden deep beneath the Mediterranean seafloor. These formations had been identified years prior through echo-sounding devices, yet no drilling had previously penetrated them. Were these formations similar to salt domes commonly found along the United States Gulf Coast? If so, what accounted for the significant presence of solid crystalline salt beneath the Mediterranean's seabed?

The scientists aboard the Glomar Challenger set out to the Mediterranean with these questions in mind, eager to uncover the answers. On August 23, 1970, they retrieved a sample comprising hardened sediment pebbles from once-soft deep-sea mud, along with granules of gypsum and volcanic rock fragments. Not a single pebble was found that might have indicated that the pebbles came from the nearby continent. In the subsequent days, solid gypsum samples were consistently recovered during drilling operations, revealing unique composition and structure characteristics indicative of desert flat formation. Surrounding sediment layers, housing minuscule marine fossils, affirmed an open ocean environment. Delving into the Mediterranean's central depths, the team extracted shiny, crystalline salt intertwined with thin layers resembling windblown silt.

At that juncture, the researchers developed a hypothesis. They proposed that around 20 million years ago, the Mediterranean functioned as a wide seaway linked to the Atlantic through two narrow straits. Subsequent crustal movements sealed these straits, initiating the evaporation of the landlocked Mediterranean. The escalating salinity from evaporation led to the extinction of scores of invertebrate species, with only a few surviving in highly saline conditions. Continuing evaporation concentrated the remaining brine, precipitating calcium sulfate and eventually more soluble sodium chloride, forming salt domes as sediments accumulated. Before these events, the Mediterranean resembled a vast, 3,000-meter-deep desert. Approximately 5.5 million years ago, seismic shifts and faulting reopened the Strait of Gibraltar, allowing water from the Atlantic to rush back into the Mediterranean. This deluge ruptured the salt flats, creating the pebbles observed in the initial Challenger sample. The basin was refilled, welcoming back normal marine life and facilitating the deposition of oceanic sediments above the ancient salt layers.

The salt, gypsum, shifts in fauna, and distinctive gravel collectively offer substantial evidence of the Mediterranean's past as a desert.

Directions: Now answer the questions.  

Paragraph 1

In 1970, geologists Kenneth J. Hsu and William B. F. Ryan conducted research aboard the oceanographic research vessel Glomar Challenger. The expedition aimed to investigate the Mediterranean's seafloor and address inquiries regarding its geological past. One inquiry focused on the sudden transformation in the Mediterranean's invertebrate fauna around 6 million years ago. While many older organisms faced near extinction, a few resilient species persisted. Some of these species migrated to the Atlantic, only to return later with new companions. What factors precipitated these near-extinction events and subsequent migrations?

1. Which of the following is NOT stated in paragraph 1 as a change that occurred in the fauna of the Mediterranean? 
   1. Most invertebrate species disappeared during a period of extinction.
   2. A few resilient species survived despite the extinction wave in the Mediterranean.
   3. Some invertebrates migrated to the Atlantic Ocean.
   4. The Mediterranean saw the arrival of new fauna species upon the return of the old migrants. 

Paragraph 3

The scientists aboard the Glomar Challenger set out to the Mediterranean with these questions in mind, eager to uncover the answers. On August 23, 1970, they retrieved a sample comprising hardened sediment pebbles from once-soft deep-sea mud, along with granules of gypsum and volcanic rock fragments. Not a single pebble was found that might have indicated that the pebbles came from the nearby continent. In the subsequent days, solid gypsum samples were consistently recovered during drilling operations, revealing unique composition and structure characteristics indicative of desert flat formation. Surrounding sediment layers, housing minuscule marine fossils, affirmed an open ocean environment. Delving into the Mediterranean's central depths, the team extracted shiny, crystalline salt intertwined with thin layers resembling windblown silt.

1. What is the implication of the statement “Not a single pebble was found that might have indicated that the pebbles came from the nearby continent”?
   1. The evidence did not support the expected origin of the pebbles.
   2. The geologists found fewer pebbles than anticipated.
   3. The geologists were specifically searching for a certain type of pebble.
   4. The pebbles likely originated from multiple sources rather than just one.

1. What is the primary objective of paragraph 3?
   1. To depict the tangible proof gathered by Hsu and Ryan
   2. To elucidate why certain questions raised earlier in the text remained unanswered based on the Glomar Challenger's discoveries
   3. To assess the methods employed by Hsu and Ryan in their seafloor exploration
   4. To delineate the most challenging issues encountered during the Glomar Challenger expedition 

Paragraph 4

At that juncture, the researchers developed a hypothesis. They proposed that around 20 million years ago, the Mediterranean functioned as a wide seaway linked to the Atlantic through two narrow straits. Subsequent crustal movements sealed these straits, initiating the evaporation of the landlocked Mediterranean. The escalating salinity from evaporation led to the extinction of scores of invertebrate species, with only a few surviving in highly saline conditions. Continuing evaporation concentrated the remaining brine, precipitating calcium sulfate and eventually more soluble sodium chloride, forming salt domes as sediments accumulated. Before these events, the Mediterranean resembled a vast, 3,000-meter-deep desert. Approximately 5.5 million years ago, seismic shifts and faulting reopened the Strait of Gibraltar, allowing water from the Atlantic to rush back into the Mediterranean. This deluge ruptured the salt flats, creating the pebbles observed in the initial Challenger sample. The basin was refilled, welcoming back normal marine life and facilitating the deposition of oceanic sediments above the ancient salt layers. 

1. As per paragraph 4, what led to the evaporation of the Mediterranean's waters?
   1. Shifts in the Earth's crust
   2. Buildup of layers of sediment
   3. Alterations in the Atlantic Ocean's water level
   4. Variations in Earth's climate

1. The term "scores" in the passage is most similar in meaning to:
   1. Members
   2. Large numbers
   3. Populations
   4. Different types 

1. Based on paragraph 4, what led to the extinction of the majority of invertebrate species in the Mediterranean? 
   1. The evaporation of vital chemicals required for their survival
   2. Geological shifts that linked the Mediterranean to the more saline Atlantic
   3. The influx of fresh species via the narrow passages
   4. Their incapacity to endure the rising salinity levels of the Mediterranean 

1. Which of the following sentences best conveys the core information presented in the highlighted sentence in paragraph 4? Incorrect options either alter the meaning significantly or omit crucial details.
   1. The Strait of Gibraltar reopened due to crustal adjustments and faulting, connecting the Mediterranean and the Atlantic and causing cascades of water between them.
   2. Crustal adjustments and faulting led to the opening of the Strait of Gibraltar, allowing water from the Atlantic to refill the Mediterranean dramatically, creating a link between the two seas.
   3. The water cascades from the Atlantic to the Mediterranean were less remarkable than the geological changes involving crustal adjustments and faulting during the connection of the Strait of Gibraltar to these seas.
   4. The Atlantic and Mediterranean became interconnected as a single sea due to crustal adjustments, faulting, and the formation of the Strait of Gibraltar, resulting in spectacular water cascades between them.

Paragraph 2

(A) Another objective for the scientists aboard the Glomar Challenger was to ascertain the source of the dome-shaped formations hidden deep beneath the Mediterranean seafloor. (B) These formations had been identified years prior through echo-sounding devices, yet no drilling had previously penetrated them. (C) Were these formations similar to salt domes commonly found along the United States Gulf Coast? If so, what accounted for the significant presence of solid crystalline salt beneath the Mediterranean's seabed? (D) 

1. 8. Directions: Look at the part of the passage that is displayed above. The letters (A), (B), (C), and (D) indicate where the following sentence could be added.
   
   Thus, scientists had information about the shape of the domes but not about their chemical composition and origin.
   
   Where would the sentence best fit? 
   1. Choice A
   2. Choice B
   3. Choice C
   4. Choice D

1. Instructions: Below is an introductory sentence for summarizing the passage. You need to choose three answer choices that represent the most significant ideas in the passage to complete the summary. Some answer choices are irrelevant or minor ideas not discussed in the passage. This question is worth 2 points.
   
   An expedition to the Mediterranean answered some long-standing questions about the ocean’s history.
   

   Answer Choices

   
   
   1. The Glomar Challenger expedition explored alterations in invertebrate fauna and certain distinctive geological characteristics.
   2. Scientists gathered fossil specimens to ascertain the identity of new species that migrated from the Atlantic alongside older species.
   3. Researchers aboard the Glomar Challenger made the inaugural discovery of the presence of dome-shaped masses beneath the seafloor.
   4. Samples retrieved from the expedition unveiled significant variances in chemical composition and the distribution of fossils among the layers of sediment.
   5. The data collected by the Glomar Challenger corroborates the beliefs of geologists regarding the evaporation of the Mediterranean and its transformation into a desert, followed by its refilling with water.
   6. Salt formations in the Mediterranean developed subsequent to tectonic shifts that opened the straits connecting the Mediterranean to the Atlantic, leading to its refilling with water.

    

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   Answer Key with Explanation for TOEFL Reading Passage - Geological Discoveries 

   1. Answer: D

   Explanation: The correct answer is Option D, The Mediterranean saw the arrival of new fauna species upon the return of the old migrants. The passage mentions that a few resilient species survived despite the extinction wave in the Mediterranean and some of these species migrated to the Atlantic. However, it does not explicitly state that new fauna species arrived in the Mediterranean upon the return of these old migrants. The focus is more on the survival and migration patterns of existing species rather than the introduction of entirely new fauna species.
   

   2. Answer: A

   Explanation: The implication of the statement "Not a single pebble was found that might have indicated that the pebbles came from the nearby continent" is that A, The evidence did not support the expected origin of the pebbles. This statement suggests that the geologists did not find any pebbles that could be definitively linked to the nearby continent, which contradicts the expectation or hypothesis that the pebbles would have originated from there. This lack of supporting evidence indicates that the pebbles likely came from a different source or sources. The passage mentions the retrieval of samples comprising hardened sediment pebbles from deep-sea mud, along with granules of gypsum and volcanic rock fragments, but none of these pebbles could be traced back to the nearby continent. Therefore, option A is the most appropriate choice as it aligns with the information provided in the passage. 

   3. Answer: A

   Explanation: ​​The primary objective of paragraph 3 is to depict the tangible proof gathered by Hsu and Ryan during their expedition aboard the Glomar Challenger. This can be inferred from the detailed description of the samples retrieved, such as the hardened sediment pebbles, granules of gypsum, volcanic rock fragments, solid gypsum samples, and crystalline salt. The paragraph focuses on the physical evidence collected from the deep-sea mud and seabed layers, highlighting the unique composition and structure characteristics that the scientists discovered. Therefore, the correct choice would be Option A. To depict the tangible proof gathered by Hsu and Ryan. This choice aligns with the paragraph's content, which emphasizes the physical samples retrieved and their significance in understanding the Mediterranean's geological history.
   

   4. Answer: A

   Explanation: The passage explains that the evaporation of the Mediterranean's waters was primarily caused by shifts in the Earth's crust. This is evident from the paragraph's description of how subsequent crustal movements sealed the straits connecting the Mediterranean to the Atlantic. This sealing process initiated the evaporation of the landlocked Mediterranean, leading to increased salinity and the extinction of many invertebrate species. These shifts in the Earth's crust are crucial to understanding the geological processes that transformed the Mediterranean from a seaway to a desert-like environment. Therefore, the correct answer is Option A. Shifts in the Earth's crust. 

   5. Answer: B

   Explanation: The term "scores" in the passage refers to a large number of invertebrate species that faced extinction due to escalating salinity in the Mediterranean. When we say "scores" in this context, we mean a significant number or multitude. Therefore, the correct answer is Option B. Large numbers. This choice captures the essence of "scores" as indicating a substantial quantity or numerous entities, aligning well with the context of many invertebrate species facing extinction. 

   6. Answer: D

   Explanation: Based on paragraph 4, the factor that led to the extinction of the majority of invertebrate species in the Mediterranean is Option D. Their incapacity to endure the rising salinity levels of the Mediterranean. The paragraph explains that as the Mediterranean became more landlocked and experienced escalating evaporation, the salinity levels increased significantly. This increase in salinity was a result of the evaporation of water, which left behind concentrated salts. Many invertebrate species were unable to survive in such highly saline conditions, leading to their extinction. This explanation directly correlates with the information provided in the passage about the impact of rising salinity on the Mediterranean's fauna.

   7. Answer: B

   Explanation: The highlighted sentence in paragraph 4 states, "Approximately 5.5 million years ago, seismic shifts and faulting reopened the Strait of Gibraltar, allowing water from the Atlantic to rush back into the Mediterranean." Option B, "Crustal adjustments and faulting led to the opening of the Strait of Gibraltar, allowing water from the Atlantic to refill the Mediterranean dramatically, creating a link between the two seas," is the best choice for several reasons. This option accurately conveys the core information presented in the highlighted sentence. It mentions crustal adjustments, faulting, the opening of the Strait of Gibraltar, and the refilling of the Mediterranean with water from the Atlantic. The sentence in option B specifies that the water refill was dramatic, which aligns with the idea of water rushing back into the Mediterranean as mentioned in the highlighted sentence.  

   Option B maintains focus on the geological processes that reopened the Strait of Gibraltar and resulted in water cascades between the Mediterranean and the Atlantic, which is the main point of the highlighted sentence.

   Option C introduces a comparison between water cascades and geological changes, which is not the primary focus of the highlighted sentence. Option A is also accurate but doesn't emphasize the dramatic nature of the water refill as strongly as option B does. 

   Option D is accurate but doesn't specifically mention the dramatic refilling of the Mediterranean, which is a key detail from the highlighted sentence.

   Therefore, option B is the best choice as it accurately conveys the core information from the highlighted sentence while maintaining the necessary emphasis on the dramatic refill of the Mediterranean. 

   8. Answer: B

   Explanation: The sentence "Thus, scientists had information about the shape of the domes but not about their chemical composition and origin" would best fit after choice B.  

   Choice A introduces the objective of the scientists to ascertain the source of dome-shaped formations.

   Choice B explains that these formations had been identified previously through echo-sounding devices but had not been drilled into. The sentence "Thus, scientists had information about the shape of the domes but not about their chemical composition and origin" logically follows choice B because it adds information about what the scientists did and did not know about these formations.

   Choice C asks whether the formations are similar to salt domes found elsewhere, which is a different aspect than the information about what the scientists knew or didn't know. Therefore, the sentence would best fit after choice B. 

   9. Answer: A, C, E

   Explanation: The table is correctly completed below.

   A. The Glomar Challenger expedition explored alterations in invertebrate fauna and certain distinctive geological characteristics.

   C. Researchers aboard the Glomar Challenger made the inaugural discovery of the presence of dome-shaped masses beneath the seafloor.

   E. The data collected by the Glomar Challenger corroborates the beliefs of geologists regarding the evaporation of the Mediterranean and its transformation into a desert, followed by its refilling with water.

    

   Correct Choices

   Option A. This choice mentions the exploration of alterations in invertebrate fauna and distinctive geological characteristics, which are indeed discussed in the passage as objectives of the Glomar Challenger expedition. It represents a significant idea. 

   Option C. This choice talks about the discovery of dome-shaped masses beneath the seafloor, which is a key discovery mentioned in the passage. It represents a significant idea.

   Option E. This choice mentions the data collected by the Glomar Challenger supporting beliefs about the Mediterranean's transformation into a desert and subsequent refilling with water, which are major themes discussed in the passage. It represents a significant idea.

    

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