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Name = ______________________
Geology 333 - Homework #2 (Mineral Resources)
Available Feb. 3; Answers are due by 10 am on Monday, Feb. 6.
(8 questions, 10 total points)

Instructions: Follow the instructions in this exercise and answer all questions either on a blank sheet of paper or directly on the question sheet, which you must print out. To access the Web sites listed below, click on the links given in this exercise. NOTE: Clicking a link opens the page in a new window. The purpose of this exercise is to explore the topic of mineral resources including hydrothermal vents, which represent a model for sulfide mineral ore deposits produced by black smokers and borate minerals.

Part I - Hydrothermal Vents (Dive and Discover - Woods Hole Oceanographic Institution)

The purpose of this part is to learn about hydrothermal vents in the ocean floor at the Dive and Discover Web site, sponsored by Woods Hole Oceanographic Institution, a private, independent, not-for-profit corporation dedicated to ocean science research. Hydrothermal vents commonly contain rich concentrations of sulfide ore minerals (Fe-, Cu-, Zn-, and Mn-sulfides that can be economically valuable) and they are considered a model for the origin of ancient massive sulfide ore deposits found on continents.

Go to the Dive and Discover: Hydrothermal Vents Web site at: <http://divediscover.whoi.edu/vents/index.html> and read the information on this page. Then, click on the link Vent Basics located on the left side in the blue column area under the heading The Basics. The direct URL is <http://divediscover.whoi.edu/vents/basics.html>. Read the information on this page including the text that appears on the black smoker figure when you click on active links, especially the circled numbers 1 - 4 and the terms Black smoker and Chimney.

Next, click on the link Videos located on the left side in the blue column area under the heading Extras. The direct URL is <http://divediscover.whoi.edu/vents/video.html>. View both videos on this page; one shows a black smoker and the other shows vent biology.

Finally, to see where hydrothermal vents have been found around the world, click on the link Vents around the World located on the left side in the blue column area under the heading The Basics. The direct URL is <http://divediscover.whoi.edu/vents/world.html>. Read the information on this page and then answer the first question.

(1) Summarize the basics of hydrothermal vents as well as black smokers and chimneys by answering the three questions below.

(a) Define hydrothermal vents, black smokers, and chimneys. (1.5 pts)


(b) Where and how do hydrothermal vents, black smokers and chimneys form? (1 pt)



(c) What is the source of the smoke in black smokers? (0.5 pts)


Next, click on the link Vent Boiling Points located on the left side in the blue column area under the heading The Basics. The direct URL is <http://divediscover.whoi.edu/vents/boiling.html>. Read the information on this page including the water boiling temperatures that appear on the figure when you click on the six question marks in red circles at different ocean depths.

Also, go the the following Web pages and read about the different depths that underwater research vessels can go as well as the pressure at several depths in the ocean.
<http://divediscover.whoi.edu/robotics/deep.html>
<http://divediscover.whoi.edu/robotics/pressure.html>


You will need to click on the different depth values to get specific information about that ocean depth. All of this information is relevant to the extraordinary temperatures of the fluids at hydrothermal vents.

(2) (a) What happens to the pressure of water with increasing depth in the ocean? (0.5 pts)


(b) What happens to the boiling point of water with increasing depth in the ocean? Explain your answer. (0.5 pts)


Next, click on the following link:
<http://divediscover.whoi.edu/vents/chemistry.html>
Read the information on this page including the information that appears below the hydrothermal vent figure when you click on the circled numbers 1 - 8.

(3) How do hydrothermal vents affect the chemical composition of seawater? Give specific examples of elements that are affected by processes at hydrothermal vents. (1 pt)



Next, learn about Vent Biology by clicking on the links Vent Life, Tubeworm Anatomy, and Chemosynthesis located on the left side in the blue column area under the heading Vent Biology. The direct URLs are:

<http://divediscover.whoi.edu/vents/biology.html>
<http://divediscover.whoi.edu/vents/anatomy.html>
<http://divediscover.whoi.edu/vents/light.html>

Read the information on these pages including information that appears when you click on the active links on each page.

(4) Explain the term chemosynthesis and why it is important to organisms that live near vents, i.e., vent biology. (1 pt)




 

Part II - Borate Ore Minerals (Rio Tinto Minerals)

Boron is one of the lightest elements (atomic number = 5) and in nature always occurs with oxygen as borate (one or more boron atoms with two or more oxygen atoms). There are more than 150 known borate minerals but only 4 or 5 are economically important.

Rio Tinto is the parent company for Rio Tinto Borates and Borax, which are the world's largest supplier of refined borate minerals. Rio Tinto Borates operates one of the world's largest borate mine in the Mojave Desert near Boron, CA. View pictures of this borate deposit and read about its geologic origin at:
<https://www.mindat.org/loc-80184.html>

(5) Describe how the borate deposits in the Mojave Desert formed. In particular, make sure to state whether the borate deposits are in sedimentary, igneous or metamorphic rock; in what specific rock the borate deposits are located; and how the rock became rich in Boron. (1 pt)

 

 

Now, go to the homepage of 20 Mule Team Borax (part of Rio Tinto Borates): <http://www.borax.com>. Under the pull-down menu Borates, select Borates by function and read the information on this page. The direct URL is <http://www.borax.com/borates-2/borates-by-function/>

(6) List and give a brief (few word) description of the twelve functions of borates, which make them useful to society. (2 pts)



 

 

 

 

 

Under the same pull-down menu Borates, select Borates in use and read the information on this page. The direct URL is
<http://www.borax.com/borates-2/borates-by-use/>.

(7) List the top four uses of borate minerals as well as three other uses. (0.5 pts)

 

 

 

 

Now, go to a Wikipedia site on borate minerals to view the most common borate minerals listed at the top of the page:
<https://en.wikipedia.org/wiki/Borate_minerals>

(8) The five borate minerals at the top of this page are the major borate ore minerals. List these 5 minerals giving both the borate mineral name and its structural formula. (0.5 pts)

 

 

NOTE: One of these borate minerals (Ulexite) is also nicknamed "TV rock" because it can transmit light similar to fiber optics (transmitting an image from one side of the mineral specimen to the other!). Check out the links showing this property!!

<http://en.wikipedia.org/wiki/Ulexite>

<http://skywalker.cochise.edu/wellerr/mineral/ulexite/ulexite2.htm>

<http://www.cs.cmu.edu/~adg/images/minerals/b/ulexite.jpg>

<http://www.mindat.org/gallery.php?cform_is_valid=1&min=4085&cf_pager_page=2>

<http://www.mindat.org/min-4085.html>