The Geological Phenomenon of Plate Tectonics
[Paragraph 1]
The Earth is not a solid, unchanging mass, but a dynamic, constantly moving system. Geologists have long studied this phenomenon known as plate tectonics. This is the theory that the Earth's lithosphere (the outer shell) is divided into a number of large and small plates that float on and move independently over the asthenosphere (the uppermost layer of the mantle).
[Paragraph 2]
The foundations of plate tectonics lie in continental drift and seafloor spreading. Alfred Wegener, a German scientist, proposed the concept of continental drift in 1912. He hypothesized that the continents once formed a supercontinent called Pangea, which fractured and drifted apart to form the continents as we know them today. However, his theory lacked a convincing mechanism to explain how these massive landmasses could move.
[Paragraph 3]
The missing piece in Wegener's theory was found with the discovery of seafloor spreading in the mid-20th century. This process occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. This provided a mechanism for Wegener's continental drift, paving the way for the modern understanding of plate tectonics.
[Paragraph 4]
There are three types of plate boundaries: convergent, divergent, and transform. Convergent boundaries occur when two plates collide, often forming mountain ranges or causing one plate to subduct beneath the other, leading to volcanic activity. Divergent boundaries happen when two plates move away from each other, creating a gap where magma rises to form new crust. Transform boundaries are where plates slide past one another, often resulting in earthquakes.
[Paragraph 5]
The theory of plate tectonics is crucial to our understanding of many geological phenomena. For example, the formation of mountain ranges like the Himalayas can be explained by the collision of the Indian and Eurasian plates. Similarly, the presence of the Pacific Ring of Fire, an area of intense seismic and volcanic activity, can be attributed to the subduction of various oceanic plates beneath continental ones.
[Paragraph 6]
The movement of tectonic plates also plays a significant role in the Earth's climate over geological timescales. The distribution of continents affects the circulation of ocean currents, which in turn impacts climate patterns. For instance, the closing of the Isthmus of Panama around 3 million years ago altered ocean circulation, leading to the glaciation of Antarctica.
[Paragraph 7]
While the concept of plate tectonics is widely accepted today, it wasn't without resistance. Many initially rejected Wegener's theory of continental drift, as it contradicted the prevailing belief of a static Earth. However, through the continual accumulation of evidence, such as matching fossils on separate continents and magnetic stripes on the seafloor, the scientific community eventually embraced the idea of a dynamic Earth.
[Paragraph 8]
In conclusion, plate tectonics revolutionized our understanding of Earth's geology, proving that our planet is not static but ever-evolving. By explaining phenomena from mountain formation to climate change, it provides a comprehensive framework for understanding Earth's past, present, and future. As scientists continue to study and refine this theory, it remains a fundamental pillar of geology.
#1 Inference:
Based on paragraph 2, what can be inferred about the initial reception of Wegener's theory of continental drift?
A) It was immediately accepted due to the groundbreaking nature of the idea.
B) It was rejected due to lack of a convincing mechanism to explain the movement of continents.
C) It was disregarded as it conflicted with religious beliefs of the time.
D) It was celebrated due to its alignment with the static Earth theory.
#2 Inference:
From paragraph 4, what can be inferred about the interactions at different types of plate boundaries?
A) Convergent boundaries are the most destructive.
B) Transform boundaries result in the creation of new crust.
C) Divergent boundaries lead to the formation of mountain ranges.
D) Each type of boundary has distinctive geological outcomes.
#3 Vocabulary:
The word 'subduct' in paragraph 4 is closest in meaning to:
A) Rise
B) Align
C) Sink
D) Slide
#4 Rhetorical Purpose:
Why does the author mention the formation of the Himalayas and the Pacific Ring of Fire in paragraph 5?
A) To provide examples of geological phenomena explained by plate tectonics.
B) To argue that plate tectonics cause most natural disasters.
C) To compare the different geological features found on Earth.
D) To show the destructive nature of plate tectonics.
#5 Factual Information:
According to paragraph 6, what effect did the closing of the Isthmus of Panama have on the Earth's climate?
A) It caused the glaciation of Antarctica.
B) It led to the formation of the Pacific Ring of Fire.
C) It resulted in the drifting of continents.
D) It triggered massive earthquakes and volcanic activity.
#6 Negative Factual Information:
All of the following are mentioned in paragraph 3 EXCEPT:
A) The process of seafloor spreading occurs at mid-ocean ridges.
B) New oceanic crust is formed through volcanic activity.
C) Seafloor spreading is a disproven theory.
D) Seafloor spreading provided a mechanism for continental drift.
#7 Inference:
What can be inferred about the role of plate tectonics in Earth's geology from paragraph 8?
A) It provides a static framework for understanding the Earth.
B) It is a controversial theory with limited acceptance.
C) It is an obsolete concept replaced by modern theories.
D) It offers a comprehensive understanding of the Earth's past, present, and future.
#8 Rhetorical Purpose:
Why does the author discuss the resistance faced by the theory of plate tectonics in paragraph 7?
A) To illustrate the initial skepticism towards the theory.
B) To argue against the validity of plate tectonics.
C) To describe the process of scientific revolution.
D) To highlight the drawbacks of the theory.
#9 Inference:
Based on paragraph 1, what can be inferred about the Earth's lithosphere?
A) It is a solid, unchanging mass.
B) It consists of several stationary plates.
C) It contains a single large plate that covers the entire Earth.
D) It is divided into several plates that move independently.
#10 Prose Summary:
An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage.
"The passage discusses the geological theory of plate tectonics and its implications."
A) Plate tectonics describes how Earth's lithosphere is divided into plates that move over the asthenosphere.
B) Plate tectonics, building on the theories of continental drift and seafloor spreading, explains various geological phenomena.
C) Wegener's theory of continental drift was initially rejected, but later accepted as a foundational concept of plate tectonics.
D) Plate tectonics has no practical application in understanding the Earth's geology.
E) The movement of tectonic plates can impact the Earth's climate.
F) Plate tectonics was disproven by the discovery of mid-ocean ridges.
Answer key:
#1 Inference:
Answer: B) It was rejected due to lack of a convincing mechanism to explain the movement of continents.
Explanation: Paragraph 2 discusses how Wegener's theory lacked a convincing mechanism, leading to its initial rejection.
#2 Inference:
Answer: D) Each type of boundary has distinctive geological outcomes.
Explanation: Paragraph 4 describes different types of plate boundaries (convergent, divergent, and transform) and the distinct geological outcomes associated with each.
#3 Vocabulary:
Answer: C) Sink
Explanation: In the context of plate tectonics, when one plate "subducts" beneath another, it essentially sinks into the mantle.
#4 Rhetorical Purpose:
Answer: A) To provide examples of geological phenomena explained by plate tectonics.
Explanation: In paragraph 5, the author uses the formation of the Himalayas and the Pacific Ring of Fire as examples to illustrate the effects of plate tectonics.
#5 Factual Information:
Answer: A) It caused the glaciation of Antarctica.
Explanation: Paragraph 6 mentions that the closing of the Isthmus of Panama altered ocean circulation, leading to the glaciation of Antarctica.
#6 Negative Factual Information:
Answer: C) Seafloor spreading is a disproven theory.
Explanation: Paragraph 3 doesn't mention anything about seafloor spreading being a disproven theory. Instead, it talks about how seafloor spreading contributed to the acceptance of the theory of continental drift and, consequently, plate tectonics.
#7 Inference:
Answer: D) It offers a comprehensive understanding of the Earth's past, present, and future.
Explanation: The last paragraph (Paragraph 8) states that plate tectonics provides a comprehensive framework for understanding Earth's past, present, and future.
#8 Rhetorical Purpose:
Answer: A) To illustrate the initial skepticism towards the theory.
Explanation: Paragraph 7 discusses the initial skepticism and resistance towards the theory of plate tectonics, showing how revolutionary ideas in science often face opposition.
#9 Inference:
Answer: D) It is divided into several plates that move independently.
Explanation: Paragraph 1 describes the Earth's lithosphere as divided into a number of large and small plates that float on and move independently over the asthenosphere.
#10 Prose Summary:
Answers: A) Plate tectonics describes how Earth's lithosphere is divided into plates that move over the asthenosphere, B) Plate tectonics, building on the theories of continental drift and seafloor spreading, explains various geological phenomena, and E) The movement of tectonic plates can impact the Earth's climate.
Explanation: A, B, and E are the most representative of the main ideas discussed in the passage. D contradicts the passage's information, F is incorrect as mid-ocean ridges actually support the theory, and C, while true, is a smaller detail compared to the major ideas encapsulated in A, B, and E.
0 Response to "TOEFL IBT Reading Example #3"
Posting Komentar