final+review

Honors Earth Science Second Semester Exam Study Guide

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__Test 1 Severe Weather__ Review your tornado safety rules for both indoor and outdoor safety. f you are outdoors the best thing to do is run to shelter..If there is no shelter you should next look to jump into a ditch or a revine...If you are inside the best thing to do is to run to the center of your basement and cover your self under a sturdy table or if possible a matress. Review your lightning safety rules. indoors- stay off the phone and don't take a bath. outdoors- stay as close to the ground as possible, making the least contact with the ground as possible. crouch with your head on your knees. stay away from high ground, trees, and bodies of water. inside a car- don't touch the metal. Describe the 5 types of potential severe weather caused by severe storms. tornadoes, hail, lightening, high wind, heavy water fall. What conditions are needed for a thunderstorm to develop? cold dry air and warm wet air What type of front does it form along? Severe weather happens along cold fronts. What cloud does it form? thunderstorms form in cumulonimbus clouds What tool do meteorologists use to determine whether there may be a tornado forming in a storm?
 * doppler radar **

__Test 2 Water World 1__ Outline the sources and sinks of ocean salts. Sources.- from the run off of rivers and surface water.- underwater volcanic eruptions. Sinks.-minerals precipitate when the water is too concentrated.-rocks form, like Limestone (limestone also prevents global warming b.c it collects CO2.) -biological processes (shells) What is the thermocline? Be able to identify it on a chart from ocean buoy data.-The thermocline is the layer between 300-1000m that changes rapidly in temp. Phil The layer of ocean water where there's a rapid change of temperature that occurs with the depth. It exists because the sun cannot reach all the way through the ocean to warm it. - Ron What is the pycnocline? Be able to identify it on a chart from ocean buoy data. The Pycnocline is the change in the waters density. Phil huh? Measure of salinity-Claire no What factors increase salinity in the oceans? the sality of water goes up when evaportation and freezing happen. What factors decrease it? increased biological activity, -precipitation, -melting, and continental margins (edges)/runoff How do salinity and temperature affect the rate that gas dissolves in the ocean? The solubility of gas increases with a drop in either water temperature or salinity. Therefore cold water can disolve more gas than warm water - Amy. Explain the ocean’s role as a carbon dioxide sink. (3 main types of sinks) Limestone forms on the bottom of the ocean so it absorbs the carbon dixiode. carbon dixiode is removed from the oceans by plants alge and planction and coral Outline the sources (2) and sinks (3) of ocean salts. Sources.- from the run off of rivers and surface water.- underwater volcanic eruptions. Sinks.-minerals precipitate when the water is too concentrated.-rocks form, like Limestone (limestone also prevents global warming b.c it collects CO2.) -biological processes (shells) Why are coral reefs of great importance to the carbon cycle? **Coral reefs removes CO2 from the water. - Megan** Explain how the ocean is involved in the carbon cycle, and its significance to global warming. **C02 leads to global warming, but coral reefs and limestone can remove it. So the oceans directly prevent global warming - Megan** //There’s much more that can be added to this thought…. Any takers??// What is the most common form of carbonate rock formed in the ocean? Limestone- Phil Basalt-Claire this is the ocean bedrock, but not a carbonate

__Test 3 Water World 2__ What causes most surface currents in the ocean? wind What direction do the equatorial currents flow? east to west What causes ocean gyres? What direction do they rotate north of the Equator? the coriolis effect. they rotate clockwise north of the equator Explain the Coriolis Effect. The deflective effect of the earth's rotation on all free-moving objects, including the atmosphere and oceans. How does it deflect currents N of the Equator? What about currents S of the Equator? North the currents go clockwise and south the currents go counter clockwise.- Phil In the north the currents go counterclockwise and in the south the currents go clockwise. --amy What is upwelling? Why does it happen? Why is it important? upwelling happens when the surface layer of the ocean is blown away by the wind, and the cold water rises. It's important because it carries nutrients to the surface, which are essential for fish, and other ocean animals Explain the model for thermohaline circulation. What drives it? Thermohaline circulation is due to density (temperature and salt). Cold, dense water flows down from the Arctic and warm water that's not very dense comes from the south What causes tides? Describe a high tide vs. a low tide. Tides happen because the sun's and the moon's gravity is pulling on the water and earth high tide is when the water is the highest and low tide is when it is the shallowest. In the simplest model, how many tides happen each day? 4 How many hours are there between two similar tides? Between a high and a low tide? 12, 6 What are neap tides? When do they happen? (phase of moon) neap tides are moderate versions of tides that happen during the first and third quarter moons What are spring tides? When do they happen? (phase of moon) very extreme versions of tides that happen during full and new moons How do El Ninos affect Michigan weather? they cause milder winters. they make winters warmer.

__Test 4 Minerals and Gems__ Be able to calculate the number of protons, neutrons and electrons in an atom. How many protons does Phosporous have? How many neutrons? 15 and 16 If Cl gained an electron, what would it become? (2 words) negitive ion How many electrons are in an atom of Al? If it lost 3 electrons, what would it become? 13 and it would become a positive ion Calculate the mass of a mineral’s formula: Calculate the mass of KAlSi3O8. 278 g How many atoms of O are in this mineral? KAl2(AlSi3O10)(OH)2 12 What’s an isotope? **Isotopes are are versions of elements that have different numbers of protons. For example Carbon-13. – Megan no! who can fix this??** Know Moh’s Scale of Hardness. Sp ecifically, what’s the highest number and mineral? The lowest? What common materials are used to test for hardness? **Finger nail (2.5), Penny (3),** **Knife (5), and Glass (7)- Megan last 2 not exactly** Knife 5.5, and Glass 6.5-7. **//Molly//** talc, it feels greasy,it is a 1, the highest is a dimond which is a 10 What are the 5 characteristics of a mineral? 1. Solid 2. Naturally-occuring 3. Definite chemical formula 4. Crystalline 5. Inorganic Be familiar with the basic mineral identification tests: fracture, 1, 2, 3 planes of cleavage, vitreous and metallic luster, streak. Vitreous: the nature of or resembling glass Conchoidal: a mineral or rock surface that is characterized by smooth, shell-like curves Metallic-silvery, gold, copper, Which minerals: fizz with acid? carbonates Are identified by a streak test? Metalic What mineral group is the most common? What is its chemical formula? **Silicates. SiO4 - Megan** A mineral has a formula that contains CO3. What type of mineral is it? Carbonate Mineral - Amy. What is a cabochon? What types of gems are cabbed? It's a gemstone that is shaped and polished instead of faceted. Types of these gems include opals, ammolite, sapphire, and jade - Amy. A rounded cut used for soft or opaque gemstones. What are facets? What types of gems are faceted? Flat "faces" done on translucent and transparent gems with a hardness greater or equal to 7 What is the definition of a carat? Carat- weight/size Explain the karat system for gold. 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 What are the 4 C’s of evaluating a diamond’s value? Cut- a good cut enhances "play of colors" Clarity- no cracks, bubbles, inclusions Color- clear, blue, yellow (most priced) Carat- weight/size

__Test 5 Economic Geology__ What are alloys? Why are they made? Know common examples of alloys. 1.) Mixture of 2 or more metals 2.) To make something stronger, lighter, cheaper, or flexible 3.) Steel, coins, brass, bronze Explain the geological origins of Michigan’s copper and iron ore deposits. What happened to create the Keweenaw Rift Zone? 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 North America began to split apart, about 1.1 billion years ago.  What are placer deposits and how are they mined?  **Placer deposits are deposites of minerals in** **a trap site (in the water). They are mined by panning, like gold panning.- Megan **   What methods are used to refine ores (leaching, electrolysis, flotation) 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. What are aggregates? Name some types found in Michigan. Crushed Rock products (glacial Deposits) gravel, sand, clay, gypsum, limestone, salt, sandstone Why does our state have so many aggregates? Michigan has lots of agrrigates because we have had a lot of glaciers in our past What are fossil fuels? Which ones are found in Michigan? Fossil fuels are are fuels formed by the natural resources such as the decomposition of buried dead organisms that lived up to 300 million years ago. They contain carbon and hydrocarbons. Coal, Oil and Natural Gas are common Michigan fossil fuels - Amy. How does petroleum form? How does coal form? Petroleum is primarily the outcome of a long process during which organisms (plants, etc.) in rock is exposed to various bacteria. As the oily organic residue decomposes, it transforms into petroleum. Coal forms when vegetation died and sank into swampy areas in layers. These layers were eventually covered by sand, clay and minerals, Sandstone and other rocks formed and put pressure on the layers of vegetation and squeezed the water out. The deeper burial and heat caused the material to turn into coal - Amy. What is the Michigan Basin? Where are the oldest and youngest rocks in the 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. What does the presence of oil, salt and coral fossils tell you about the past history of Michigan? limestone salt and coral fossils tell that michigan used to be in the tropics and was an ocean Where are each of these mineral resources located in Michigan: copper, iron, salt, aggregates, petroleum? Copper- U.P. Iron- Western U.P. Salt- L.P. Aggregates- the whole mitten-Colleen The rocks of the Michigan Basin are the source of commercial quantities of [|petroleum] What are the 3 traditional types of mining methods? Underground Open Pit **Panning- Megan**

Be able to 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 applying 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. What are scrubbers? Explain how they work. (adhesion) Scrubbers are tools used to scrub the sulfur out of the smoke released by coal-burning boilers. most scrubbers use limestone to which can be used to absorb sulfur under the right conditions. limestone is then mixed with water and sprayed into the coal combustion gases. the limestone captures the sulfur and "pulls" it out. Limestone and sulfer together form a wet paste that disables the sulfur from getting into the air. Why don’t the Great Lakes have an acid rain problem? Limestone absorbs all of the acid from the acid rain and balances the PH levels out. Its a natural scrubber __Test 6 Igneous Processes__ Know the rock cycle processes: 3 basic rock types and how each form. an igneous rock can either form underground or above ground. underground- when the magma is trapped in small pockets inside the earth. above ground- also formed when lava cools above ground. Sedimentary?? **Rocks are broken down by erosion and weathering, and then are made into rocks by lithication. - Megan** What is the relationship between crystal size and cooling rate? Slow cooling-large crystals Fast cooling-small crystals Define these igneous rocks types: volcanic (extrusive), intrusive (plutonic), glass. Volcanic, or extrusive, rocks form when lava solidifies above the ground. Plutonic, or intrusive, rocks weren’t able to reach the surface, so they crystallize at depth. Some igneous rocks don’t have crystals. They are called glasses-Obsidion Pummace and Scoria- What is the relationship between types of lava (viscosity, explosiveness, amount of silica), where they are located, and if the eruption is from a shallow or deep source? Pahoehoe - This is thin lava that flows smoothy and formed by small volumes of hot, fluid basalt. The higher the volume of lava, the faster the flow. They move forward in tongues or lobes and has a glassy, plastic skin. It usually solidifies to a smooth surface. Aa - these flows are usually emitted from a vent at a high rate with fountaining. These flows can push down houses and walls and and have a very rough surface when they solidify. Both Pahoehoe and Aa lava occur in Hawaii. The more silica in the lava, the slower it moves - Amy. Compare felsic vs. mafic rocks (chemistry and color). Felsic rocks are lighter colored, contain more quartz and feldspar. High SiO2. Mafic rocks are darker colored, contain more iron minerals. Define and explain a hot spot. when a volcano is formed away from a plate, like in the center is placed there because of a mantle plume, which is when the lava pushes to the crust, gets extremely hot and forces its way through to the surface. For each of the 4 types of volcanoes: give a geographic example, describe the physical shape and size of the volcano, its lava chemistry and temperature, its eruption behavior (degree of explosiveness) and any pyroclastics it produces. Fissure eruptions: Keweenaw Peninsula, hottest lava, deep source depth, ocean and continent location, low explosiveness. Stratovolcanoes: Mt. Saint Helans, alternating/cooler lava, shallow source depth, continent location, high/alternating explosiveness. Shield: Largest volcano, very hot lava, deep source depth, ocean location, low explosiveness. Cinder cones: Smallest volcano, Sunset Crater, cooler lava, shallow source depth, ocean and continent location, small bursts of explosiveness. What type of volcanism occurred in Michigan? Where did it happen? It was a fissure erruption flood basalt volcano. Plates spreading apart caused this. It happened in the Keweenaw Rift Be able to interpret and to identify these igneous textures: vesicular, porphyritic. The vesicular texture of bubble-holes in a rock is caused by gas venting during formation Define and identify each of these lava products: bomb, ash, pumice, obsidian. Ash is about the same size as sand. Ash is a powdery residue Obsidian is very hard, looks very much like glass. It breaks into sharp edges, that can easily cut through many materials. You can find obsidian in any color, however obsidian is mostly black or brown

__Test 7 Tectonics/Earthquakes__ Recognize and describe each of these ocean floor features: the continental shelf, abyssal plains, mid-ocean ridge, trench, seamounts, transform faults. -CONTINENTAL SHELF: THE TRUE END OF THE CONTINENT, EVEN IF UNDERWATER. -ABYSSAL PLAINS: DEEPEST PART OF THE OCEAN -MID-OCEAN RIDGE: WHERE NEW PLATES ARE FORMED. -TRENCH: WHERE PLATES ARE TAKEN UNDER AND MELTED AWAY -SEAMOUNTS: UNDERWATER ISLANDS -TRANSFORM FALUTS: FAULT WHICH RUNS ALONG THE BOUNDARY OF A TECTONIC PLATE THAT MOVES HORIZONTALLY. --DANIELLE H.  What igneous rock makes up the ocean floor? What igneous rock makes up the majority of the continents? granite is continent, basalt is oceanic Which is more dense, oceanic or continental crust? Oceanic What are the 4 layers of Earth’s interior? the crust, mantle, outercore, and innercore. Which layer is liquid? the outer core. How do plates move? plates "float" upon the asthenosphere What 3 rock units comprise a plate? lithoshpere, continental crust, and oceanic crust What layer of the mantle do they “float” on? asthehosphere Compare and contrast each of these seismic waves: P, S, surface P waves are first and compressional, S waves are second and transverse and surface waves are last and a combination Know the behavior of P and S waves as they travel through the Earth p waves- can travel through anything. s waves- cannot travel through outercore (liquid) What are shadow zones and how are they created? he shadow zone is the area of the earth that does not receive any waves. The shadow zone results from S waves being stopped entirely by the liquid core and P waves being bent by the liquid core. How is an earthquake’s amplitude determined? by the height of the tallest s wave, you measure it from the baseline to the very top How is the distance to an earthquake determined? the distance between the p and s wave - the s-p lag time. the longer the lag time, the farther away the earthquake is Compare the Richter and Mercalli scales. Richter: Earthquake's Energy Based Scale Mercalli: Earthquake Damage Based Scale What are tsunamis and how do they begin? Tsunamis are large waves (up to 100 ft). They can be caused by eruptions and earthquakes. Explain liquefaction and how it happens. liquefaction is when the surface of land basically becomes quick sand. this happens because the water table raises up due to an earthquake and floods and saturates the earth. __Test 8 Structural Geology/Plate Tectonics__ Be able to identify the types of faults(4) and folds(3). Faults: 1. Normal Fault or Reverse Fault - one side of the fault slips down. 2. Stike-Slip or Transform Fault - The fault slides horizontally along the fault line. 3. Thrust Fault - One side of the fault elevates vertically. 4. Horst and Graben Fault - Tension pulls perpendicular tothe fault line and sections of land fall. Folds: 1. Compressional Stress - Rock layers are pushed together. 2. Tensional Stress - Pulls rock/dirt layers apart. 3. Shear Stress - Stress is parallel to the face of the material. - Amy Explain the formation of the Appalachian, Himalayan and Andes Mountains. The Appalachin Mountains were formed through a series of plate collisions. There are elongated belts of folded and thrusted faults of marine sedimentary rock, volcanic rock and ocean floor. The Appalachians were originally located near the center of supercontinent Pangaea. The same type of mountain chain continues in Morocco and Scotland. The Himalayans are much younger than the Appalachians are are considered youngfold mountains. They are known as fold mountains because they consist of a series of parallel ridges or folds that extend for 2500km. They formed when the seabed rapidly folded and was raised into longitudinal ridges and valleys. The Indian plate moving north and colliding with the Eurasian plate created this. The Andes formation is also due to the massive force of plate tectonics. This is one of the longest mountain ranges and many peaks are volcanic. The Antarctic plate sliding beneath the South American plate has created these mountains, volcanoes and many earthquakes in the area. These are relatively new mountains. Amy. Who is Wegener? What theory did he propose? What evidence did he collect? Wegener was a cartographer and meteorologist who popularized the idea of continental drift The shapes of many continents are such that they look like they are separated pieces of a jig-saw puzzle. Many fossil comparisons along the edges of continents that look like they fit together suggest species similarities that would only make sense if the two continents were joined at some point in the past. Know what these landforms look like, how they form, and what plate boundaries they are associated with. (Some are found along multiple boundaries): island arc rift valley folded mountains mid-ocean ridge transform fault trench Define each of these plate boundaries by explaining what's happening there: a subduction zone, a convergent plate boundary, a divergent plate boundary , a transform boundary. onvergent= two plates pushing together. Divergent= two plates pulling apart. Transform=two plates (side by side) rubbing against each other. Convergent Boundaries Land forms= island arcs, trenches, volcanic mountains, folded mountains, & subduction zone. Subduction zone is when one plate is under another. The more oceanic plate goes underneath the plate with more land. Island Arc System= chain of small volcanic islands. Geographic examples= Aleution, Mariana, and Tongol islands. Divergent boundaries Landforms= mid-ocean ridge, fissure volcanos, and rift valley. Where in the U. S. are two famous hot spots? (one on land, one in the ocean) hawaii and yellowstone List __specific geographic examples__ of each of the following: a transform fault on land San Andreas Fault - Amy. a divergent plate boundary on land Iceland - Amy. a continent-continent convergent plate boundary Collision of India into Asia creating the Himalaya Mountains - Amy. a continent-ocean plate subduction zone Andes Mountains. Volcanoes occur on the crust as the ocean plate slides underneath - Amy. an ocean-ocean plate subduction zone Marianas Trench. Phillipine plate sliding under the Pacific plate - Amy. Explain how hot spots such as Hawaii indicate the speed and direction of ocean plate movements. Assuming the hot spot remains stationary, then the rate of migration of the volcanism along the island chain gives the rate of plate movement along the Hawaiian Hot Spot - Amy. Explain seafloor spreading. Where is the youngest seafloor? The oldest? as the mid-ocean ridge spreads lava comes out and creates new ocean floor What is the relationship between the age of ocean floor and its distance from the mid-ocean ridge? the farther away the older..... What is thought to be the mechanism that “drives” plate motion? Push, Pull and Drag. Ridge Push is a force that applies to ridges and causes them to spread. Hot material then fills the gap, gravity pulls it away from the center and the gap gets wider for more material to fill in. Slab pull applies to cool plates that are more dense than the material beneath them, causing them to sink and pull the rest of the plate behind it. Plate Drag is when the mantle layers are separated and hot material flows between them causing friction and convection leadingto plate movement - Amy. TRENCHES ? --DANIELLE H.  What is paleomagnetism? How does it help to date rocks and show plate motions? paleomagnetism is when mafic igneous rocks point towards the north pole. it helps date rocks because where they point depends on their age. it shows plate motions because the north pole never actually moves, jus t the older rocks point in different places because the continents were in different places. Explain “polar wandering”. the north pole is in a "different place", because igneous, mafic rocks point to where it is. the north pole doesnt really move, it is just the continents moving due to plate tectonics. What are terranes? Give a geographic example of a piece of continent built of terranes. Terranes are little pieces of land that get stuck together. An example would be Alaska. What three processes can create metamorphic rocks? Heat, pressure, and chemically active fluids
 * //But with who??//**

__Test 9 Erosion and Weathering__ List examples of mechanical and chemical weathering, and be able to define each. mechanical weathering: frost-wedging, root- wedging, exfoliation frost-wedging: ice freezing and expanding in the cracks of rock root-wedging: tree roots growing between the cracks in rock

chemical weathering: oxidation, carbonic acid, biological activity (lichens) Oxidation- When rocks, rich in iron minerals, become rusty. They receive a yellow, reddish color. Carbonic Acid-Rain dissolves carbon dioxide, and as it falls through the atmosphere, the acid ionizes What is creep? Slump? creep: slow movement of sediment due to gravity slump: quick downward movement of sediment Exfoliation? Exfoliation are surface parallel fracture systems in rocks that lead to erosion of concentric slabs. As the molton rock, such as granite, is risen and unearthed, the pressure is taken off of it. As a result of the pressure release, small cracks form. Over time, weathering, plants, gravity, etc. open the cracks further, and slabs break off, rather than the erosion of fine particles over time. A good example of this is Half Dome in Yosemite National Park - Amy. Explain how the longshore current affects beaches. Be able to predict how a groin will change sediment deposition and erosion patterns. The beach sand gets dragged by the water in the same direction of the longshore drift. What 3 common soils exist? Identify them by color, environment and chemistry. Black/brown: The black is very rich in organic and is in temperate areas (not oxidized) Red: In humid and warm ideas, and unlike brown/black soil it is oxidezed. White/Grey: Found in desert like areas, but not as porous. Contrast these 3 soil textures: sand, loam, clay. What is each good for? Soil texture is determined by the amount of sand, silt and clay in a soil. Sandy soils are coarse textured, gritty and individual particles can be seen with the naked eye. Sandy soils do not hold water, they drain easily but are easily worked. They warm up quickly in the spring. Clay is sticky and plastic-like when wet. A clay type soil holds water and nutrients and is better for gardening. The individual particles are extemely small and can only be seen with an electron microscope. Loam has a combination of sand, silt and clay. Loam is preferred in horticulture because it is easy to work with - Amy. Be able to read the soils composition chart (triangle graph) to determine soil type. What is the relationship between the degree of roundness of sand and its age? the rounder the sand is the older it is since it has been polished more by erosinal processes. What is the relationship between the degree of roundness of sand and proximity to its source area? What is the relationship between the degree of sorting of sand and proximity to its source area? the farther from the source area the rounder the sand is. What is the relationship between sediment size and water velocity? When velocity decreases in water, larger sediments are deposited first. They then become part of the bed. When velocity continues to decrease, only clay and the finest silt will be left suspended. In still water, even the clay will be deposited, from largest particles to smallest - Amy. How can a dune be stabilized so that it does not migrate? Plant grass on it Review evidence of Michigan glacial erosion: grooves, kettle lakes. Kettle lakes are usually in groups and forms when a block of ice falls off a glaciern. Finger lakes are being eroded or grounded out, they are gouged out in the direction the glaciers were moving Explain the formation of moraines. Moraines are formed from the unconsolidated debris that gets pushed in front, sides and base of glaciers. Rock particles of all sizes are picked up and deposited in ridges as the ice melts - Amy. What are stratified drift and till and where would  each be found? Stratified Drift is glacial sediment that has been redistributed and stratified by flowing water. The melting icewater of the glacier carries the particles and sorts them, usually with the coarser materials near the point of origin. Till is disorganized heaps of unstratified rocks of various sizes. It is deposited by the glacier without water transportation - Amy. What are: erratics? Kames? Drumlins? Eskers? Erratics are rocks that differ in size and type to the ones native to an area where it rests. A Kame is a hill or mound composed of sand or gravel that accumulates on a retreating glacier. It is then deposited on the land surface as the glacier melts. Drumlins are whale shaped hills with their long axis parallel to the movement of ice and the blunt end facing into the glacial movement. there are usually many of them together and they are layered like waves. An Esker is a long, winding ridge of stratified sand/gravel that forms in or under a glacier. Ice walls melt away and a river forms depositing the sand and gravel - Amy. When did the last ice sheets leave Michigan? It was a tough winter so I would say around April in the U.P., but the major ice sheets that formed the Great Lakes was about 9,500 to 8,000 year ago when they retreated to Hudson Bay - Amy. Hah! HUMOR!!! How were the Great Lakes formed? During the Ice Age much of the northern hemisphere was covered by ice. The Laurentide Ice Sheet covered Canada and the northern U.S. As glaciers advanced, giant ice sheets wore down mountains and created valleys. About 14,000 years ago, the Ice Sheets began retreating and the geological changes created the Great Lakes. The meltwater filled the giant holes left by the glaciers. As the glaciers retreated, the lakes were probably much larger, but as different outlets for the water closed up or were created, the lakes leveled off at their present day heights. This final shape of the lakes occurred about 6,000 years ago. The glaciers also left behind around 6,360 lakes in Michigan - Amy. Recognize which hills in Michigan are moraines by their pattern. Moraines are arranged parallel to the shorelines. Where the glaciers came in is why it is caused where it happens.

__Last Unit! Sedimentary Rocks and Their Uses__ Review how and where each of these sedimentary rocks are formed: conglomerate, coal, sandstone, limestone, shale, coquina, halite. Which are clastic? clastics- made of little pieces. bioclastics- formed from little pieces of living things. Which are chemically formed? evaporite-left behind by water precipitate-leaves water What conditions are necessary for fossilization? The main conditions are rapid burial and possession of hard parts such as shells, bones or teeth. Burial means that they quickly become buried in sedimentaion, or enclosed in tree sap, tar, ice, etc. - Amy. What are trace fossils? Give some examples. gastroliths rocks that were in dinasaurs bellies, coprolites are remnants from an animal such as a bone or a tooth On the Geologic Time Scale: During what era where dinosaurs prevalent? mesozoic The common fossil invertebrates of Michigan, such as trilobites? paleozoic Very little life except for algae? precambrian The Ice Ages? There were four major time intervals of ice ages. 800-600 million years ago, 460-430 million years ago, 350-250 million years ago, and in the last 4 million years. Each of these time periods saw glaciers advance and retreat several times. We are generally considered to currently be in an ice age and the modern climate is a very short warm period between glacial advances. The Great Ice Age started about a million years ago, but the last major ice sheet to cross the northern U.S. peaked about 20,000 years ago (Laurentide Ice Sheet) and is what formed the Great Lakes - Amy. Be able to work a simple half-life problem, calculating amounts of parent, daughter and the time elapsed. (This would include using a half-life curve such as the one we did for homework.) What is the special use for Carbon-14 in dating? a living thing takes in carbon 14 and when dead it stops the level of carbon-14 in fossil detremines how long its been dead Using nuclear notation, 14C and 12C are examples of what? Interpret stratigraphic maps by using relative dating methods (crosscutting, superposition, etc.) Be able to state relative ages of rock layers and faults. Interpret erosional boundaries seen in stratigraphic maps (the 3 different types of unconformities). Be able to recognize the rock symbols for sandstone, limestone and shale. Know the difference between porous, permeable and impermeable rocks and examples of each. What types of sediment are impermeable? Shale,(desert sand),granite, slate is impermeable and clay Very permeable? sand, gravel conglomerate, sandstone and limestone Explain how a well works: non-flowing vs. artesian. an artesian well never has to be pumped unlike non flowing well What is the water table? Be able to recognize it on a diagram, along with the zones of aeration and saturation Explain the concepts of an aquitard and an aquifer. As Aquifer is the area under the water table of water bearing permeable rock that can be used as a water well. An Aquitard is an impermeable layer along as aquifer - Amy.