GEOL 1001_ Chap 2 Hmwrk (1)
docx
keyboard_arrow_up
School
University of the Incarnate Word *
*We aren’t endorsed by this school
Course
1001
Subject
Geology
Date
Apr 3, 2024
Type
docx
Pages
2
Uploaded by ChefJellyfishPerson2266
CHAPTER 2 HOMEWORK QUESTIONS
1. What was the first line of evidence that led early investigators to suspect that the continents were once connected?
The first line of evidence that led early investigators to suspect that the continents were once connected was the observation of similar rock formations and fossils on opposite sides of the Atlantic Ocean. Geologists noticed that the same types of rocks and fossils were found in South America and Africa, suggesting that these two continents were once joined and then separated.
2. What two aspects of Wegner’s continental drift hypothesis were objectionable to most Earth scientist?
a. The lack of a plausible mechanism for the movement of continents. Wegner's hypothesis proposed that continents moved through the oceanic crust, but this was not supported by the known behavior of rocks and minerals.
b. The lack of sufficient evidence to support the idea of large-scale continental movement. While Wegner presented some geological and biological evidence, it was not considered strong enough to convince most Earth scientists at the time.
3. List the three types of plate boundaries and describe the relative motion at each of them.
Is the plate boundary a destructive or constructive plate? a. Divergent plate boundary: At a divergent plate boundary, two plates are moving away
from each other. This creates a gap or rift between the plates, which can fill with molten magma from the mantle, creating a new crust. This type of plate boundary is constructive, as it creates new land and expands the size of the ocean floor.
b. Convergent plate boundary: A convergent plate boundary occurs when two plates are
moving towards each other. Depending on the type of crust involved, one plate may slide beneath the other (subduction), resulting in the formation of volcanoes and mountain ranges. This type of plate boundary is destructive, as it can cause earthquakes and destroy existing landforms.
c. Transform plate boundary: At a transform plate boundary, two plates are moving past each other in opposite directions. This creates a fault line, which can cause earthquakes. This type of plate boundary does not create or destroy land, so it is neither
constructive nor destructive.
4. What is the average rate of seafloor spreading in modern oceans?
2.5 centi per year
5. Explain why the rate of lithosphere production roughly balances with the rate at which it is destroyed.
The rate of lithosphere production is balanced with the rate of destruction due to the process of plate tectonics. As new lithosphere is formed at divergent boundaries, old lithosphere is subducted at convergent boundaries, maintaining a balance. Additionally, the Earth's internal heat drives the movement of plates, which also contributes to the balance between production and destruction. This balance is necessary for the maintenance of the Earth's surface and its processes.
6. What role are mantle plumes thought to play in the convective flow within the mantle?
Mantle plumes are thought to be responsible for the convective flow within the Earth's mantle. They are columns of hot, buoyant material that rise from the core-mantle boundary and can reach the surface. Their heat and motion create convection currents that circulate within the mantle, driving the movement of tectonic plates and influencing the formation of volcanic hotspots.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help