Economic+Geology+Review


 * Honors Earth Science Objectives Economic Geology**

HESMASTER has done the first check – correct answers now appear in this cool purple color. Note my comments in red- these need help/fixes. There are still empty questions out there for you to do! 1. Explain how gold alloys are rated in karats. What percentage of gold is in a 10K ring? 24k= Pure Gold 100% 10k- 41% 18k= 74% Gold 14k= 58% Gold __ Morgan __ 2. Describe each of these 3 ways that minerals form: hydrothermal and magmatic emplacement and sedimentary deposits (placers). __Hydrothermal__- Deposites from warm (copper) __Magmatic__ __Emplacement__- Formed from liquid rock/ hardened underground (gold) __Sedimentary__ __Deposits__- Deposits of eroded rockers, in layer __ Morgan Lorkowski __ 3. What happened billions of years ago in the western Upper Peninsula to create lava (and later) the copper deposits? the land tried to split and the magma came up and when it hardened it left behind rich deposits of metals- Phil L.    The copper came much later, not during the rift formation. Who knows when and how? The copper came from hydrothermal deposits it cracked about 1.1 billion years ago--Danielle H. 4. What and where is the Keweenaw Rift? Its a 2,000 (km) long geoloigical rift in the center of the North American continent and part of the south-central North American plate. It formed when the North American crator began to split apart, about 1.1 billion years ago. -Dani 5. Where are each of these mineral resources located in Michigan: copper, iron, salt, gypsum, aggregates? Mark them on the map outline below and identify with a key! Iron- Central UP Copper- Along the Keewinaw Rift, From the top of the Keewinaw Rift to the lower Western UP. Salt- Around the Michigan Basin Gypsum- North Eastern LP Aggregates- Central Michigan

6. Compare the 2 traditional types of mining methods. What are the pros and cons of each? There is Shaft minning Pros- way to get minerals- does litte to the surface Cons- Very Dangerous- expensive to build There is Open Pit Minning Pros= Safer- Cheaper- Easier Cons- dust blows around land use __ Morgan __ 7. Describe some different ways to reclaim strip (open pit) and shaft (underground) mines. __Shaft__ Grow Veggies and no bugs attack it, organic store toxic waste Bomb Shelter __Open Pit__ Can fill to lake Revegitate Turn into park or sudvision Trash Dump Morgan 8. What are alloys? Why are they made? Give some examples. 1.) Mixture of 2 or more metals 2.) To make something stronger, lighter, cheaper, or flexible 3.) Steel, coins, brass, bronze __ Morgan __ 9. Explain these different refining techniques: froth flotation, electrolytic separation, leaching, smelting. Froth flotation- separation by density, dense fluid added, rock sinks, refined material floats. Electrolytic separation: extracting metals from solution by applyuing an eletric current. (metals will accumalate at the electrode) Leaching- A chemical separation;adding chemicals to dissolve metal, then remove metal from solution. Smelting-Adding other chemicals to ore;melt to extract metal. -Dani  10. What impact does the refining of many metallic ores have on the environment? How can lakes with low pH be restored? --Danielle H. **  11. What are scrubbers? Explain how they work. (adhesion)  "Air pollution control devices" They remove acids, some particulates, and gases from industrial exhaust streams. It takes away unwanted pollutants. –Dani  Explain the role of adhesion in this. 12. Why don’t the Great Lakes  have an acid rain problem? Because the great lakes have lime stone- Megan OK…but why is that a //good// thing?  Limestone absorbs all of the acid from the acid rain and balances the PH levels out. Its a natural scrubber.--Danielle H.  13. Give examples of 3 types of aggregates. Why does Michigan have so many of them? Michigan has lots of agrrigates because we have had a lot of glaciers in our past. - Megan Crushed Rock products (glacial Deposits) gravel, sand, clay, gypsum, limestone, salt, sandstone __ Morgan __ 14. What does the presence of limestone, salt and coral fossils tell you about the past history of Michigan? In the Southern hemisphere, we were once a tropical and warm ocean. -Dani p    15. What is the Michigan Basin? is a [|geologic basin] centered on the [|Lower Peninsula] of the US state of [|Michigan]. The feature is represented by a nearly circular pattern of geologic [|sedimentary] [|strata] in the area with a nearly uniform structural [|dip] toward the center of the peninsula. The rocks of the Michigan Basin are the source of commercial quantities of [|petroleum]. The most actively drilled-for source of [|natural gas] in recent years has been [|shale gas] from the [|Devonian] [|Antrim Shale] in the northern part of the basin. __ Morgan __ In my own words... The Michigan Basin is in the central LP of Michigan. It was formed by glaciers. This is where the newest rocks are. There is lots of fuel that comes from here. - Megan 16. What are brines? What products do we make from them? water nearly or fully saturated from salt. We use it to preserve things (ex. fish, vegetables, and meat) -dani Although we do use brines in this way, most are used for something else. Anyone know the answer? Brine can also be used to separate organic impurities. It is also used to make salt. - Megan
 * It pollutes the environment and creates acid rain. The PH levels in a lake can be restored by putting limestone in it.