Reference no: EM132807777

GSCI 1050 Earths Dynamic Environment - University of Connecticut

QUESTION 1

Introduction
Geologists use various consistent features to identify minerals. Although there are thousands of minerals on Earth, there are not that many that are frequently found in rocks. The same mineral found in different parts of the world will look the same and have characteristic features and a consistent chemical composition. Minerals help us identify rocks and rocks tell us volumes about the history of Earth, they are the clues in our detective mystery. Learning to identify minerals and rocks is a key first step in learning more about our planet.

Objectives
When you have completed this lab, you should be able to...

1. Describe how to classify minerals using their principal physical properties. These include hardness, cleavage, color, streak, luster, crystal form, reaction to acid, and taste.
2. Use their physical properties to identify a series of minerals which are present in many common types of rock.
3. Determine what types of minerals are used in everyday products.

Part I: Mineral Properties

Rocks and minerals can tell you a lot about the geology of an area. It is therefore important to be able to identify the minerals that comprise rocks in order to accurately identify a specific rock type. Each mineral has a unique set of physical characteristics that geologists use in order to identify it.

Activity 1: How do geologists identify minerals?

Imagine you are a geologist stationed somewhere on the East Coast of the United States. While working to uncover the geologic history of the Appalachian Mountains, your group encounters a great variety of minerals. Step 1: Have a look at the images of minerals below. NOTE: you do not know the names of these minerals!

Mineral A

Mineral B

Mineral C

Mineral D

Mineral E

Mineral F

Mineral G

Mineral H

Mineral I

Step 2: In the text box below, list five (5) methods of classifying or characterizing the minerals in the images above for the purposes of identification. In other words, what are 5 types of observations that would allow you to distinguish between each mineral from the next? Example of a classification: Color. (Hint: Other classifications may be found in the Objectives section above.)

Step 3: Choose two (2) minerals from the images above. Based on what you can see in the images for those two minerals, use the 5 methods you came up with in Step 2 to describe each mineral (make sure you include the letter associated with the minerals you choose). You can also write these descriptions in the text box below. Note: Some of the methods you use to characterize these minerals may rely on physically interacting with the minerals in person. If you chose a method like this, then make an effort to predict what you might observe (you must say WHY you made this prediction! What other observations allowed you to predict that it would, for instance, have a streak of a particular color?)

QUESTION 2
For the following questions (2-18), use the information provided in the important information part of the Lab 3 page slide show to identify the minerals and their properties and fill in the blanks.

Based on the image above, this mineral has ________ luster. If you were able to scratch a streak plate with the sample, it would create a black streak. The name of this mineral is ___________.

QUESTION 3

This mineral is quartz. It is colorless to grayish in color. When broken, this mineral exhibits has a series of knobbly concave shapes with no preferred planes of weakness. This is known as ____. When allowed to grow without obstruction, quartz crystals grow as prisms with sides. The hardness of quartz is ______ on the Moh's scale. When you apply a drop of hydrochloric acid (HCI) on the surface of this mineral, will bubbles form? (yes or no)

QUESTION 4

The extenor of this mineral has mat planes. because the mineral is transparent, you can see that planes parallel to the extenor planes run through the mineral as potential breakage surfaces. These planes have ____________ different orientations, and they are oriented at right angles relative to each other (hence the cubic shape of the mineral sample). You find that you can scratch it with a fingernail. One of the more intrepid members of your group licks this mineral and reports that it tastes salty. You apply NCI to this sample and see that _________ (something, nothing) happens. After you do this, no one wants to lick the mineral anymore because no one wants a mouthful of acid. You instead lightly dab the acid away with a paper towel because you suspect that some future student may lick this mineral. This mineral is

QUESTION 5

This mineral is calcite. It can come in a variety of colors and has flat planes. You can see flat cracks running through the sample that run parallel to the exterior planes. There are _____________ (instert number value here) distinct breakage planes and they ________ (are / are not) at right angles to each other. You find that you ______________ (can / cannot) scratch it with a fingernail and you (can / cannot) scratch it with a copper penny. When you place a small drop of HCI acid on it, you see that the acid ________ (does / does not) bubble on the surface of the mineral.

QUESTION 6

For the example of the mineral you see here, you note that it has a bluish-green color. You find that it ________ (does / does not) scratch a copper penny and ________ (does / does not) scratch glass. The outside of the mineral looks cubic but on breakage surfaces you can find cleavage planes. What mineral is this?

QUESTION 7

This breaks readily into flat sheets, meaning it has __________ (enter number value) plane(s) of cleavage. You can see through individual sheets but when you have several together they have a sort of silver-ish, sometimes light brown color. Mineral can be scratched with a copper penny but not with a fingernail. You apply HCI acid and see that ___________ (something I nothing) happens. This mineral is

QUESTION 8

The mineral shown above is graphite. This mineral is entirely composed of the element . Graphite is gray and moderately shiny. It can be easily scratched with a fingernail. Cleavage planes are easily identified (yes or no). When you scrape it on a streak plate you find that it leaves a mark. You find that it can do the same thing on a piece of paper. Graphite is commonly used in this writing utensil:

QUESTION 9

Mineral shines in a metallic fashion and is gray in color. The shape of the mineral is cubic and it breaks along planes parallel to its sides. It has cleavage in ______ directions at 90 degrees. Your instructor told you not to lick this mineral but one of your group members licks this mineral anyway and notes a metallic flavor. They later suffer from lead poisoning. They learn from this incident that they _______ (should / should not) lick this mineral. This mineral cannot be scratched with a fingernail but can be scratched with a copper penny. This mineral is _____.

QUESTION 10

The hardness of this mineral on the Moh's scale is 1.5-2. This mineral ______ (can / cannot) be scratched with a fingernail. The sample looks
like a set of tablets separated by cleavage planes. There may be other cleavage planes but you find it hard to tell. The sample is colorless. When you apply HCI acid you see that _________ (something / nothing) happens. This mineral is

QUESTION 11

Mineral looks like a lump of metal with small sparkling specks. Mineral scratches glass when tested. There are no apparent planes of weakness. When scraped on a streak plate the mineral leaves a black mark. You find that the mineral is capable of attracting a magnet.

QUESTION 12

This mineral is black and shinier on some surfaces than others. You determine that the shiny surfaces are 2 cleavage planes that do not intersect at a right angle. Hardness tests show that the mineral can scratch glass.

QUESTION 13

Orthoclase Feldspar - Scotland

Mineral is pinkish in color and opaque. It scratches glass and when you turn it in the light you see shiny surfaces that you decide are cleavage planes. There are 2 cleavage planes which are oriented at right angles to each other. Nothing happens when you apply HCI.

QUESTION 14

Mineral is black in color and can scratch glass. Some surfaces are shinier than others and you are able to determine that the shiny surfaces are cleavage planes. There are two cleavage planes that are very close to being at right angles to each other.

QUESTION 15

This mineral is green to yellowish brown in color. The specimens are often not a single grain, but rather many grains interlocked together. The crystals are small but you don't see any cleavage planes. The mineral is capable of scratching glass.

QUESTION 16

This mineral is white and opaque. Based on the shininess of different surfaces you can determine that there are 2 cleavage planes and that they appear to at a ninety-degree angle. This mineral can scratch glass.

QUESTION 17

When multiple sheets are stacked together, this mineral is black in color and flaky at the edges. It can break into thin sheets. It can be scratched with a penny.

QUESTION 18

This mineral looks like a lump of metal and feels heavy in the palm of your hand. It has no apparent cleavage planes and is hard enough to scratch glass. A streak test yields a rust-colored mark. This mineral does not attract or repel magnets.

QUESTION 19

Part II: Identifying Minerals in Rocks

In actual field situations, it is rare to find nice mineral samples lying around. Usually, geologists have to use small samples of minerals found inside of rocks to identify them. You now have a bag of tricks for identifying minerals, It is time to see if you can apply the information that you have learned.

Mineral Identification Activity: Identify minerals in the igneous rock samples you see in the images below. Use what you have learned to see if you can identify the minerals in the two rock samples provided. Its not expected that you ace this part - just give it your best educated guess!

Step #1: Review the common rock-forming minerals mentioned in the "Mineral Properties" slideshow, which you can find in the important information section of the Lab 3 page. Pay attention to the chemical formula included in each mineral's slide. If you need to look up the abbreviations of different elements, refer to this periodic table of the elements.

Step #2: Look at this pie chart which tells you the relative abundances of the most common elements in Earth's crust. Use this pie chart in combination with the minerals' chemical formulas in order to determine which of the minerals would be common in Earth's crust.

Step #3: Consider the images of Rocks #1 and #2 below. These rocks represent typical samples of bedrock you may find in the continental crust (rock #1) and the oceanic crust (#2).

Step #4: In the text box below, list any/all minerals that you think could be in Rock #1 and then do the same for Rock #2 (be sure to clearly label which minerals you're listing for which rock). Next to each mineral's name, you should write a sentence that describes any/all of the observations (color, cleavage, grain shape, etc.) that helped you identify the minerals in the images below. Again, do your best here-- we know these are not perfect examples of what each mineral looks like. Also, YOU DO NOT NEED TO STATE THE ROCK TYPE. We'll do rock identification in next week's worksheet.

Hint: For Rock #1, you will benefit from reviewing the PowerPoint slide files provided in the important information section of the Lab 3 page...

Rock #1 (continental crust):

QUESTION 20

Now that you've identified the different minerals in Rocks #1 and #2, visit this website to consider the densities of different common rock-forming minerals. The values are in units of grams per cubic centimeter. Also the mineral listed as hornblende is a version of the mineral amphibole.

In case you're also considering these minerals, you can assume that the density of biotite mica is roughly the same as muscovite mica, and that pyroxene's density is 3.1-4 grams per cubic centimeter,

As you may have noticed, many of these minerals have a significant range in possible density values. Why is this the case? Explain your reasoning. You may want to think about their chemical formulas, and the conditions in which these minerals can be found in the crust.

QUESTION 21

Provide answers to both parts of this question in the text box below.

A. Using what you've thought about for the last two questions, would you expect Rock #1 or Rock #2 to be denser? Explain your reasoning.

B. Based on your answer to part A, how do you think the mineral composition of rock in the oceanic crust versus the continental crust affects the processes involved in plate tectonics? Hint: How would the proportions of minerals in a rack relate to what happens in a subduction zone?

QUESTION 22
Part III: Mineral Uses

Section 1: Mineral product matching

How do you use minerals on a daily basis? Below is a list of products and also a list of minerals and their chemical formulas all of which are in the box of mineral samples). Use the formulas and other properties of the minerals (such as hardness, color, etc.) along with the 'Uses of Mineral Resources' file to match each mineral to the product it is used to make (one mineral per product).

Toothpaste Makeup Car Battery Table Salt Turns (antacid tablets) Drywall & Plaster Glass & Sandpaper

A. Fluorite CaF2 B. Biotite K(Mg,Fe)3(Aisi3O10)(F,OH)2 C. Galena PbS D. Halite NaCI E. Calcite CaCO3 F. Gypsum CaSO4-2H2O G. Quartz SiO2

QUESTION 23

Section 2: Mining and Waste

Golden Sunlight Mine (GSM), near Whitehall, Montana, opened in 1983 and is still open today. It is one of the properties owned by the Canadian company Barrick Gold Corp. Take a look at the attached satellite image of Golden Sunlight Mine. Some remediation (slope stabilization) has been done by planting and growing vegetation on the west side of the West Waste Rock Dump Complex and an the northeast side of the East Waste Rock Dump Complex.

Use the boundaries in the image above to estimate the approximate percentage of land surface area that is used for actual pit mining as opposed to the storage of mining waste products (including both waste rock and tailings). The approximate percentage of land surface used for pit mining as compared to that used in mine waste storage is:

90-100%

70-85%

45-55%

15-30%

QUESTION 24

For a sense of scale:

Estimate the number of acres inside Tailings Impoundment #2 using the scale box 100 acres) on the map. 0.5 points Save Answer

QUESTION 25

If an American football field, including the end zones, is about 1.32 acres, approximately (mathematically) how many football fields would fit inside Tailing Impoundment #2? Use 250 acres for the size of Tailing Impoundment #2. Show your calculations here.

QUESTION 26
Using what you see in the map, why do you think Tailings Impoundment #1 looks different than Tailings Impoundment #2?

QUESTION 27

The Montana Department of Environmental Quality (DEQ) has recently received an application from GSM to amend their operating permit. This would include adding one new pit northeast of the mine and extending the larger Mineral Hill pit, although within the previous permit boundary. This additional mine area would extend the life of the mine for two years, allowing the company to continue to explore the area without closing. The additional mining would result in an estimated 4.2 million tons of ore and 52.6 million tons of non-ore rock (waste).

Of all the material extracted from the ground in these new sections of GSM, what percentage by weight) of this material is are and what percentage is waste? Show your calculations and remember to use proper significant figures.

QUESTION 28
What might be some incentives of the DEQ and the community to approve the permit? What might be some incentives not to approve the permit? In all of your written responses (not just this question), please use complete sentences ad make sure you clearly describe the information that supports your argument.

QUESTION 29

Section 3: Ore Grades and Mining

The grade of an ore is the concentration of the desired material within the rock. There is more metal (a higher concentration] in higher grade metal ores. Ore grades are often given in percentages or in units of ppm (defined below). Percentages, which most of us are familiar with through our class grades, are actually a measurement of "parts per total parts." In the case of grades on an exam, if you received a 92% on your 100-point exam, you received 92 points out of a possible 100 points. This is similar to ores: If a nickel ore has a grade of 2%, it means there are 2 pounds of nickel for every 100 pounds of ore. It also means that there are 2 grams of nickel for every 100 grams of ore, etc., so long as the unit of comparison remains the same within the percentage calculation (pounds to pounds or grams to grams or ounces to ounces, etc.).

Some sources say that the average single family home in the United States uses about 420 pounds of copper within the plumbing, appliances, building wire, and more. In the twenty-first century, an average copper grade ore might be

How many pounds of 0.6% grade copper ore needs to be mined in order to obtain 420 pounds of copper? Show your work and pay attention to proper significant figures. Hint: tf the ore grade is 0.6%, it means that for every 100 lbs. of ore, there is 0.6%, or 0.6 lbs. of copper. So, if you need 100 lbs. of ore for every 0.6 lbs. of copper, you con then scale this conversion up to 420 lbs. of copper.

QUESTION 30

Another frequently used unit of measurement for ore grades is "parts per million" or ppm. Instead of finding the concentration per 100 parts, like the percentage, ppm finds concentration out of one million parts. This unit is used to represent metals that often occur in smaller concentrations. A gold ore with a 2 ppm ore grade would have 2 pounds of gold for every 1,000,000 pounds of ore. An equivalent unit is grams/ton (since there are 1,000,000 grams, or 106 grams, in a metric ton). Thus a 2 ppm grade gold ore would also have 2 grams of gold for every ton of ore.

A gold coin called a Krugerrand (from South Africa) has approximately 31.1 grams of gold in it. Remember that 1 metric ton =10106 grams. How many metric tons of 15 ppm grade gold ore need to be mined in order to get enough gold for a single Krugerrand? Show your work here.

QUESTION 31

How much waste product (in metric tons) is created? Show your work.

QUESTION 32

Globally, production of ores has increased quite significantly over the past century, while ore grade has steadily declined. Propose explanations for both of these trends.

QUESTION 33

Section 4: Cut-off Grade, Mint Productivity, and legacy mines

Many aspects influence the financial productivity of a mine. Obviously, the presence of the desired material is key, but both geological and non-geological elements influence the overall success of the mine, Some important factors, in addition to the strategy of the company and their management, include:
• Resource quality: Ease with which the ore can be mined, the type of mineral resource, the site of the ore deposit, ore grade (concentration of desired material within the rock)
• Input Costa: Labor, energy, and water use) infrastructure and services) other materials used in the mining process
• Macroeconomic Factors: Metal prices, ability to obtain credit and interest rates, exchange rates
• Other Factors: Governmental permitting rules, financial resources, social and political factors

Together these factors determine whether a site is worth mining and/or whether a mine will stay open and, if so, for how long. They will also influence the extensiveness of the mine (how much land is mined), the amount of waste products created, the number of jobs maintained, and more. A mining company can control only parts of some of these factors.

Recall that the grade of an ore is the concentration of the desired material within the rock.

The cut-off grade of an ore is essentially the lowest grade of an ore that is worth mining. If the ore grade is less than the cut-off grade, then a mining company will not make money mining that or, It might seem as if the cut-off grade of an ore is determined permanently at the time of exploration and mine opening, but in reality the cut-off grade changes throughout the lifetime of the mine and thus changes the estimates of the amount of ore in a reserve). For example, if cut-off grade drops, the mine is now able to profitably extract metal from an ore with a lower ore grade (a lower concentration of metal in the ore).

The above is summarized in this general rule:
Cut-Off Grade is the lowest grade of an ore that is worth mining.
• When mining gets easier, cut-off grade drops.
• When mining gets more difficult, cut-off grade increases.
1, For the factors listed below, note whether the cut-off grade would likely rise or fall and explain why. The first one (a) is an example:

a. Increased market price of the metal?:
Fall. If the mine can receive more money for each ounce that they produce, then the extra costs of processing more lower concentration are are worthwhile. Therefore an increased market price could lead to a lower cut-off are grade.
b. New extraction technologies?
c. More stringent environmental regulations?

QUESTION 34

Review the map of GSM. Why do you think that so little of the GSM is comprised of the open pit itself compared to the size of the dumps and tailings impoundments? Use what you wrote about in your previous answers to explain your argument, and remember that this map does not tell you how tall or shallow the surface topography is in this location.

QUESTION 35

Many closed mines exist throughout the United States (and other countries). lithe cut-off grade drops for ores once extracted from these legacy mines, what might happen to these old mines?

QUESTION 36

The Golden Sunlight Mine (GSM) near Whitehall, Montana, is relatively close to dozens of legacy rHning operations. In the fall of 2012, GSM won an award from the U.S. Bureau of Land Management for helping to reuse materials from legacy silver and gold mines. The GSM partnered with other groups to remove and process the tailings from the legacy mines, deposit the reprocessed tailings into a more modern, lined, tailings pond, and reclaim the old site (all with proper permitting). The partners and related contractors benefit financially, the historic sites are cleaned up with a reduced amount of federal/state (taxpayer) expense, and new jobs are provided. In 2011-2012, GSM had at least 10 different contracts to bring in historic mine materials for processing, including from sites on public lands.

These same legacy tailings have been around for a long time and remained untouched for years. What factors might have changed to allow this type of "ore processing" partnership to exist today?

Note: *All Images are attached in file

Attachment:- Worksheet.rar