You Rock!© 2009 Barbara J. Shaw Ph.D., Science A to ZPermission is granted to make and distribute copies of this lesson plan for educational use only.

http://en.wikipedia.org/wiki/Geologic_timehttp://www.fas.org/irp/imint/docs/rst/Sect2/Sect2_1b.htmlhttp://pubs.usgs.gov/gip/fossils/rocks-layers.htmlhttp://pubs.usgs.gov/gip/dynamic/understanding.htmlhttp://en.wikipedia.org/wiki/Rock_cyclehttp://explorations.ucsd.edu/Voyager/Activities/images/playdoh.gifhttp://en.wikipedia.org/wiki/Alfred_wegnerhttp://scotese.com - specifically: http://scotese.com/newpage5.htmhttp://www.math.montana.edu/~nmp/materials/ess/geosphere/inter/activities/plate_calc/pangaea_map.gifhttp://www.pbs4549.org/antarcti/platetec.htmhttp://chemistry.about.com/od/growingcrystals/Growing_Crystals.htmhttp://earthsci.org/mineral/rockmin/mineral/mineral_i_d.html

Background:Uniformitarianism is the assumption that the natural processes operating in the past are the same as those that can be observed operating in the present. "The present is the key to the past."

Catastrophism is the idea that Earth has been affected by sudden, short-lived, violent events that were sometimes worldwide in scope.

Various geologists in the 1700-1800s began to publish descriptions of the sequences they studied. As the Geologic Column grew, estimates of their ages were made using mainly deposition rates. Individual sequences within the column were assigned times in the past which resulted from the column estimates. It became conventional to give a name to a sequence that seemed to represent a long span of time but with certain diagnostic properties (e.g., a collection of life forms that, while evolving, possessed similarities). These sequences became Periods in a temporal-stratigraphic nomenclature and all rocks contained within the sequence made up a System. Subdivision of Periods into smaller time spans yielded Epochs, with their Rocks being Series. Broader divisions of time made up some number of Periods (each younger one overlying an older Period - Law of Superposition) were called Eras.

Geologists and other scientists use the geological time scale to describe the timing and relationships between events that have occurred during the history of Earth. The table of geologic periods presented here agrees with the dates and nomenclature proposed by

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the International Commission on Stratigraphy, and uses the standard color codes of the United States Geological Survey.

Evidence from radiometric dating indicates that the Earth is about 4.570 billion years old. The geological or deep time of Earth's past has been organized into various units according to events that took place in each period. Different spans of time on the time scale are usually delimited by major geological or paleontological events, such as mass extinctions. For example, the boundary between the Cretaceous period and the Paleogene period is defined by the extinction event, known as the Cretaceous–Tertiary extinction event, that marked the demise of the dinosaurs and of many marine species. Older periods that predate the reliable fossil record are defined by absolute age.

We study Earth's history by studying the record of past events that is preserved in the rocks. The layers of the rocks are the pages in our history book.

Most of the rocks exposed at the surface of Earth are sedimentary--formed from particles of older rocks that have been broken apart by water or wind. The gravel, sand, and mud settle to the bottom in rivers, lakes, and oceans. These sedimentary particles may bury living and dead animals and plants on the lake or sea bottom. With the passage of time and the accumulation of more particles, and often with chemical changes, the sediments at the bottom of the pile become rock. Gravel becomes a rock called conglomerate, sand becomes sandstone, mud becomes mudstone or shale, and the animal skeletons and plant pieces can become fossils.

An idealized view of a modern landscape with some plants and animals that could be preserved as fossils.

As early as the mid-1600's, the Danish scientist Nicholas Steno studied the relative positions of sedimentary rocks. He found that solid particles settle from a fluid according to their relative weight or size. The largest, or heaviest, settle first, and the smallest, or lightest, settle last. Slight changes in particle size or composition result in the formation of layers, also called beds, in the rock. Layering, or bedding, is the most obvious feature of sedimentary rocks.

Originations of major life forms

Sedimentary rocks are formed particle by particle and bed by bed, and the layers are piled one on top

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of the other. Thus, in any sequence of layered rocks, a given bed must be older than any bed on top of it. This Law of Superposition is fundamental to the interpretation of Earth history, because at any one location it indicates the relative ages of rock layers and the fossils in them.

Layered rocks form when particles settle from water or air. Steno's Law of Original Horizontality states that most sediments, when originally formed, were laid down horizontally. However, many layered rocks are no longer horizontal. Because of the Law of Original Horizontality, we know that sedimentary rocks that are not horizontal either were formed in special ways or, more often, were moved from their horizontal position by later events, such as tilting during episodes of mountain building.

Rock layers are also called strata (the plural form of the Latin word stratum), and stratigraphy is the science of strata. Stratigraphy deals with all the characteristics of layered rocks; it includes the study of how these rocks relate to time.

Scientists now have a fairly good understanding of how the plates move and how such movements relate to earthquake activity. Most movement occurs along narrow zones between plates where the results of plate-tectonic forces are most evident.There are four types of plate boundaries:

Divergent boundaries -- where new crust is generated as the plates pull away from each other.

Convergent boundaries -- where crust is destroyed as one plate dives under another. Transform boundaries -- where crust is neither produced nor destroyed as the plates slide

horizontally past each other. Plate boundary zones -- broad belts in which boundaries are not well defined and the

effects of plate interaction are unclear.

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Divergent boundaries:Divergent boundaries occur along spreading centers where plates are moving apart and new crust is created by magma pushing up from the mantle. Picture two giant conveyor belts, facing each other but slowly moving in opposite directions as they transport newly formed oceanic crust away from the ridge crest.

Perhaps the best known of the divergent boundaries is the Mid-Atlantic Ridge. This submerged mountain range, which extends from the Arctic Ocean to beyond the southern tip of Africa, is but one segment of the global mid-ocean ridge system that encircles the Earth. The rate of spreading along the Mid-Atlantic Ridge averages about 2.5 centimeters per year (cm/yr), or 25 km in a million years. This rate may seem slow by human standards, but because this process has been going on for millions of years, it has resulted in plate movement of thousands of kilometers. Seafloor spreading over the past 100 to 200 million years has caused the Atlantic Ocean to grow from a tiny inlet of water between the continents of Europe, Africa, and the Americas into the vast ocean that exists today.

The volcanic country of Iceland, which straddles the Mid-Atlantic Ridge, offers scientists a natural laboratory for studying on land the processes also occurring along the submerged parts of a spreading ridge. Iceland is splitting along the spreading center between the North American and Eurasian Plates, as North America moves westward relative to Eurasia.

The consequences of plate movement are easy to see around Krafla Volcano, in the northeastern part of Iceland. Here, existing ground cracks have widened and new ones appear every few months. From 1975 to 1984, numerous episodes of rifting (surface cracking) took place along the Krafla fissure zone. Some of these rifting events were accompanied by volcanic activity; the ground would gradually rise 1-2 m before abruptly dropping, signalling an impending eruption. Between 1975 and 1984, the displacements caused by rifting totalled about 7 m.

East Africa may be the site of the Earth's next major ocean. Plate interactions in the region provide scientists an opportunity to study first hand how the Atlantic may have begun to form about 200 million years ago. Geologists believe that, if spreading continues, the three plates that meet at the edge of the present-day African continent will separate completely, allowing the Indian Ocean to flood the area and making the easternmost corner of Africa (the Horn of Africa) a large island.

Convergent boundaries:The size of the Earth has not changed significantly during the past 600 million years, and very likely not since shortly after its formation 4.6 billion years ago. The Earth's unchanging size implies that the crust must be destroyed at about the same rate as it is being created, as Harry Hess surmised. Such destruction (recycling) of crust takes place along convergent boundaries where plates are moving toward each other, and sometimes one plate sinks (is subducted) under another. The location where sinking of a plate occurs is called a subduction zone.

The type of convergence -- called by some a very slow "collision" -- that takes place between plates depends on the kind of lithosphere involved. Convergence can occur between an oceanic

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and a largely continental plate, or between two largely oceanic plates, or between two largely continental plates.

If by magic we could pull a plug and drain the Pacific Ocean, we would see a most amazing sight -- a number of long narrow, curving trenches thousands of kilometers long and 8 to 10 km deep cutting into the ocean floor. Trenches are the deepest parts of the ocean floor and are created by subduction.

Off the coast of South America along the Peru-Chile trench, the oceanic Nazca Plate is pushing into and being subducted under the continental part of the South American Plate. In turn, the overriding South American Plate is being lifted up, creating the towering Andes mountains, the backbone of the continent. Strong, destructive earthquakes and the rapid uplift of mountain ranges are common in this region. Even though the Nazca Plate as a whole is sinking smoothly and continuously into the trench, the deepest part of the subducting plate breaks into smaller pieces that become locked in place for long periods of time before suddenly moving to generate large earthquakes. Such earthquakes are often accompanied by uplift of the land by as much as a few meters.

On 9 June 1994, a magnitude-8.3 earthquake struck about 320 km northeast of La Paz, Bolivia, at a depth of 636 km. This earthquake, within the subduction zone between the Nazca Plate and the South American Plate, was one of deepest and largest subduction earthquakes recorded in South America. Fortunately, even though this powerful earthquake was felt as far away as Minnesota and Toronto, Canada, it caused no major damage because of its great depth.

Oceanic-continental convergence also sustains many of the Earth's active volcanoes, such as those in the Andes and the Cascade Range in the Pacific Northwest. The eruptive activity is clearly associated with subduction, but scientists vigorously debate the possible sources of magma: Is magma generated by the partial melting of the subducted oceanic slab, or the overlying continental lithosphere, or both?

As with oceanic-continental convergence, when two oceanic plates converge, one is usually subducted under the other, and in the process a trench is formed. The Marianas Trench (paralleling the Mariana Islands), for example, marks where the fast-moving Pacific Plate converges against the slower moving Philippine Plate. The Challenger Deep, at the southern end of the Marianas Trench, plunges deeper into the Earth's interior (nearly 11,000 m) than Mount Everest, the world's tallest mountain, rises above sea level (about 8,854 m).

Subduction processes in oceanic-oceanic plate convergence also result in the formation of volcanoes. Over millions of years, the erupted lava and volcanic debris pile up on the ocean floor until a submarine volcano rises above sea level to form an island volcano. Such volcanoes are typically strung out in chains called island arcs. As the name implies, volcanic island arcs, which closely parallel the trenches, are generally curved. The trenches are the key to understanding how island arcs such as the Marianas and the Aleutian Islands have formed and why they experience numerous strong earthquakes. Magmas that form island arcs are produced by the partial melting of the descending plate and/or the overlying oceanic lithosphere. The descending plate also

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provides a source of stress as the two plates interact, leading to frequent moderate to strong earthquakes.

The Himalayan mountain range dramatically demonstrates one of the most visible and spectacular consequences of plate tectonics. When two continents meet head-on, neither is subducted because the continental rocks are relatively light and, like two colliding icebergs, resist downward motion. Instead, the crust tends to buckle and be pushed upward or sideways. The collision of India into Asia 50 million years ago caused the Eurasian Plate to crumple up and override the Indian Plate. After the collision, the slow continuous convergence of the two plates over millions of years pushed up the Himalayas and the Tibetan Plateau to their present heights. Most of this growth occurred during the past 10 million years. The Himalayas, towering as high as 8,854 m above sea level, form the highest continental mountains in the world. Moreover, the neighboring Tibetan Plateau, at an average elevation of about 4,600 m, is higher than all the peaks in the Alps except for Mont Blanc and Monte Rosa, and is well above the summits of most mountains in the United States.

Transform boundaries:The zone between two plates sliding horizontally past one another is called a transform-fault boundary, or simply a transform boundary. The concept of transform faults originated with Canadian geophysicist J. Tuzo Wilson, who proposed that these large faults or fracture zones connect two spreading centers (divergent plate boundaries) or, less commonly, trenches (convergent plate boundaries). Most transform faults are found on the ocean floor. They commonly offset the active spreading ridges, producing zig-zag plate margins, and are generally defined by shallow earthquakes. However, a few occur on land, for example the San Andreas fault zone in California. This transform fault connects the East Pacific Rise, a divergent boundary to the south, with the South Gorda -- Juan de Fuca -- Explorer Ridge, another divergent boundary to the north.

The San Andreas fault zone, which is about 1,300 km long and in places tens of kilometers wide, slices through two thirds of the length of California. Along it, the Pacific Plate has been grinding horizontally past the North American Plate for 10 million years, at an average rate of about 5 cm/yr. Land on the west side of the fault zone (on the Pacific Plate) is moving in a northwesterly direction relative to the land on the east side of the fault zone (on the North American Plate).

Oceanic fracture zones are ocean-floor valleys that horizontally offset spreading ridges; some of these zones are hundreds to thousands of kilometers long and as much as 8 km deep. Examples of these large scars include the Clarion, Molokai, and Pioneer fracture zones in the Northeast Pacific off the coast of California and Mexico. These zones are presently inactive, but the offsets of the patterns of magnetic striping provide evidence of their previous transform-fault activity.

Not all plate boundaries are as simple as the main types discussed above. In some regions, the boundaries are not well defined because the plate-movement deformation occurring there extends over a broad belt (called a plate-boundary zone). One of these zones marks the Mediterranean-Alpine region between the Eurasian and African Plates, within which several smaller fragments of plates (microplates) have been recognized. Because plate-boundary zones

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involve at least two large plates and one or more microplates caught up between them, they tend to have complicated geological structures and earthquake patterns.

We can measure how fast tectonic plates are moving today, but how do scientists know what the rates of plate movement have been over geologic time? The oceans hold one of the key pieces to the puzzle. Because the ocean-floor magnetic striping records the flip-flops in the Earth's magnetic field, scientists, knowing the approximate duration of the reversal, can calculate the average rate of plate movement during a given time span. These average rates of plate separations can range widely. The Arctic Ridge has the slowest rate (less than 2.5 cm/yr), and the East Pacific Rise near Easter Island, in the South Pacific about 3,400 km west of Chile, has the fastest rate (more than 15 cm/yr).

Evidence of past rates of plate movement also can be obtained from geologic mapping studies. If a rock formation of known age -- with distinctive composition, structure, or fossils -- mapped on one side of a plate boundary can be matched with the same formation on the other side of the boundary, then measuring the distance that the formation has been offset can give an estimate of the average rate of plate motion. This simple but effective technique has been used to determine the rates of plate motion at divergent boundaries, for example the Mid-Atlantic Ridge, and transform boundaries, such as the San Andreas Fault.

Current plate movement can be tracked directly by means of ground-based or space-based geodetic measurements; geodesy is the science of the size and shape of the Earth. Ground-based measurements are taken with conventional but very precise ground-surveying techniques, using laser-electronic instruments. However, because plate motions are global in scale, they are best measured by satellite-based methods. The late 1970s witnessed the rapid growth of space geodesy, a term applied to space-based techniques for taking precise, repeated measurements of carefully chosen points on the Earth's surface separated by hundreds to thousands of kilometers. The three most commonly used space-geodetic techniques -- very long baseline interferometry (VLBI), satellite laser ranging (SLR), and the Global Positioning System (GPS) -- are based on technologies developed for military and aerospace research, notably radio astronomy and satellite tracking.

Among the three techniques, to date the GPS has been the most useful for studying the Earth's crustal movements. Twenty-one satellites are currently in orbit 20,000 km above the Earth as part of the NavStar system of the U.S. Department of Defense. These satellites continuously transmit radio signals back to Earth. To determine its precise position on Earth (longitude, latitude, elevation), each GPS ground site must simultaneously receive signals from at least four satellites, recording the exact time and location of each satellite when its signal was received. By repeatedly measuring distances between specific points, geologists can determine if there has been active movement along faults or between plates. The separations between GPS sites are already being measured regularly around the Pacific basin. By monitoring the interaction between the Pacific Plate and the surrounding, largely continental plates, scientists hope to learn more about the events building up to earthquakes and volcanic eruptions in the circum-Pacific Ring of Fire. Space-geodetic data have already confirmed that the rates and direction of plate movement, averaged over several years, compare well with rates and direction of plate movement averaged over millions of years.

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The rock cycle is a fundamental concept in geology that describes the dynamic transitions through geologic time among the three main rock types: sedimentary, metamorphic, and igneous. Each type of rock is altered or destroyed when it is forced out of its equilibrium conditions. An igneous rock such as basalt may break down and dissolve when exposed to the atmosphere, or melt as it is subducted under a continent. Due to the driving forces of the rock cycle, plate tectonics and the water cycle, rocks do not remain in equilibrium and are forced to change as they encounter new environments. The rock cycle is an illustration that explains how the 3 rock types are related to each other and how processes change from one type to another over time.

The original concept of the rock cycle is usually attributed to James Hutton, the eighteenth century father of geology. The rock cycle was a part of Hutton's uniformitarianism and his famous quote: no vestige of a beginning, and no prospect of an end, applied in particular to the rock cycle and the envisioned cyclical nature of geologic processes. This concept of a repetitive non-evolutionary rock cycle remained dominant until the plate tectonics revolution of the 1960s. With the developing understanding of the driving engine of plate tectonics, the rock cycle changed from endlessly repetitive to a gradually evolving process. The Wilson cycle (a plate tectonics based rock cycle) was developed by J. Tuzo Wilson during the 1960s and 70s.

When rocks are pushed deep under the Earth's surface, they may melt into magma. If the conditions no longer exist for the magma to stay in its liquid state, it will cool and solidify into an igneous rock. A rock that cools within the Earth is called intrusive or plutonic and will cool very slowly, producing a coarse-grained texture. As a result of volcanic activity, magma (which is called Lava when it reaches Earth's surface) may cool very rapidly while being on Earth's surface exposed to the atmosphere and are called extrusive or volcanic rocks. These rocks are fine-grained and sometimes cool so rapidly that no crystals can form and result in a natural glass, such as obsidian. Any of the three main types of rocks (Igneous, Sedimentary, and Metamorphic rocks) can melt into magma and cool into igneous rocks.

Rock masses of igneous origin have no sooner cooled than they begin to change. The solids with which the magma is charged are slowly dissipated, lava flows often remain hot and steaming for many years. These gases attack the components of the rock and deposit new minerals in cavities and fissures. The zeolites are largely of this origin. Even before these "post-volcanic" processes have ceased, atmospheric decomposition or weathering begins as the mineral components of volcanic and igneous rocks are not stable under surface atmospheric conditions. Rain, frost, carbonic acid, oxygen and other agents operate continuously, and do not cease until the whole mass has crumbled down and most of its ingredients have been resolved into new products or carried away in aqueous solution. In the classification of rocks these secondary changes are generally considered unessential: rocks are classified and described as if they were ideally fresh, though this is rarely the case in nature.

Epigenitic change (secondary processes) may be arranged under a number of headings, each of which is typical of a group of rocks or rock-forming minerals, though usually more than one of these alterations will be found in progress in the same rock. Silicification, the replacement of the minerals by crystalline or crypto-crystalline silica, is most common in felsic rocks, such as rhyolite, but is also found in serpentine, etc. Kaolinization is the decomposition of the feldspars,

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which are the most common minerals in igneous rocks, into kaolin (along with quartz and other clay minerals); it is best shown by granites and syenites. Serpentinization is the alteration of olivine to serpentine (with magnetite); it is typical of peridotites, but occurs in most of the mafic rocks. In uralitization secondary hornblende replaces augite; this occurs very generally in diabases; chloritization is the alteration of augite (biotite or hornblende) to chlorite, and is seen in many diabases, diorites and greenstones. Epidotization occurs also in rocks of this group, and consists in the development of epidote from biotite, hornblende, augite or plagioclase feldspar.

Rocks exposed to high temperatures and/or pressures can be changed physically or chemically to form a different rock, called metamorphic. Regional metamorphism refers to the effects on large masses of rocks over a wide area, typically associated with mountain building events within orogenic belts. These rocks commonly exhibit distinct bands of differing mineralogy and colors, called foliation. Another main type of metamorphism is caused when a body of rock comes into contact with an igneous intrusion that heats up this surrounding country rock. This contact metamorphism results in a rock that is altered and re-crystallized by the extreme heat of the magma and/or by the addition of fluids from the magma that add chemicals to the surrounding rock (metasomatism). Any pre-existing type of rock can be modified by the processes of metamorphism.

Rocks exposed to the atmosphere are variably unstable and subject to the processes of weathering and erosion. Weathering and erosion breaks the original rock down into smaller fragments and carries away dissolved material. This fragmented material accumulates and is buried by additional material. While an individual grain of sand is still a member of the class of rock it was formed from, a rock made up of such grains fused together is sedimentary. Sedimentary rocks can be formed from the lithification of these buried smaller fragments (clastic sedimentary rock), the accumulation and lithification of material generated by living organisms (biogenic sedimentary rock - fossils), or lithification of chemically precipitated material from a mineral bearing solution due to evaporation (precipitate sedimentary rock). Clastic rocks can be formed from fragments broken apart from larger rocks of any type, due to processes such as erosion or from organic material, like plant remains. Biogenic and precipitate rocks form from the deposition of minerals from chemicals dissolved from all other rock types.

Procedure:This unit is a three-week introduction to geology, covering the major concepts in this science. Each lesson is designed for 45 minutes covering:

Geologic Concepts:o Geologic Time

Uniformitarianism vs. Catastrophism Superposition Fossils

o Earth’s Interior Plate Tectonics

Plate Boundarieso Minerals and Matter

Rock Cycle Igneous Rock

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Volcanos Sedimentary Rock

Weathering Metamorphic Rock

Metamorphism

Week 1 Week 2Monday #1 Introduction to Geology:

What do I know What do I want to learn

#6 Plate Tectonics Students solve the puzzle of

Pangaea

Tuesday #2 Geologic Time: Students transform number of

years into millimeters, and walk back to the formation of the earth

#7 Plate Boundaries Students model the different

types of plate boundaries, convergent, divergent, and transform boundaries

Wednesday #3 Superposition Students construct a model of the

layers of sediment to demonstrate superposition

#8 Rock Cycle Students model the rock cycle

Thursday #4 Fossils Students research, draw, and

place their fossils on the Geologic Time Line from lesson #2.

#9 Minerals and Matter Students grow their own minerals

and apply the mineral definitions to their results

Friday #5 Model of the Earth Students construct a model of the

Earth and it’s layers

#10 Igneous, Sedimentary, Metamorphic Rocks Students conduct tests on rock to

group according to different traits

Week 3#11 Follow-up: What I want to know. Students explore in depths one of the questions they asked during this two-week unit using the scientific method (all or part).

One week prior to starting this unit, divide the students into groups of 5. Ask students to divide the list of organism (on page 17) so that they each are responsible for 4 of them. Assign the students to research their organisms, and be prepared for lesson 4 with their information.

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Lesson 1: Introduction to Geology

Materials (1 set for class): Butcher paper ~ 4’ x 5’ Permanent markers (variety of colors)

Preparation: Gather materials Divide butcher paper into 2 columns. Title the first column, “What we know,” and the

second column, “What we want to learn.”

Directions: Ask students, “What do you know about Geology? What do you know about our planet

Earth?” Write down answers on butcher paper to keep through this unit. Record responses in the first column of the butcher paper. Ask students to expand on this

information. Differentiate between information students “know” from information that they think they know.

Optional, have a 3rd column (between “What we know,” and “What we want to learn.”) titled “What we think we know.”

Lesson 2: Geologic Timeline

Materials (1 set per team of students): 15’ strip of butcher paper markers (in variety of colors) meter sticks rulers Copy of geologic time scale (page 3)

Preparation: Gather materials Cut butcher paper into 15 feet strips, one per student team

Directions:Divide students into groups of 5

How long is 4.6 billion years?4.6 billion = 4,600,000,000.

That is a HUGE number! Just how big is it really? Today, we are going to create a timeline, to make a model of years by converting one million years to one millimeter. (1,000,000 years = 1mm) How big is one millimeter? Look at your ruler. If you look carefully between the 0 and 1 centimeter (cm), you can see 10 lines. Each space between those lines is approximately 1 millimeter.

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We are going to measure 4 Eons (very long times) Eras (The Phanerozoic Eon is divided into 3 Eras), and then we are going to measure Periods (with a total of 11).

The Phanerozoic (use a green marker):Write down time ending: 545Subtract the time starting: 0 How long is your line? 545 mm

There are three Eons in the Precambrian that are not shown. They are:

Proterozoic (use a red marker): Write down time ending: 2,500Subtract the time starting: 545How long is your line? 1,955 mm

Archean (use a blue marker):Write down time ending: 3,800Subtract the time starting: 2,500How long is your line? 1,300 mm

Hadean (use a black marker):Write down time ending: 4,500Subtract the time starting: 3,800How long is your line? 700 mm

Measure each Eon and draw (with the color Phanerozoicmarker indicated above) a line across the tape, label each section of tape (with the color marker indicated above name with the proper Eon. Proterozoic

Archean

Hadean

Next, you need to mark off the Eras that are in the Phanerozoic. This time, you do the math to figure out how big each era will be:

Cenozoic:Write down time ending:Subtract the time starting: ____How long is your line (in mm)?

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Mesozoic:Write down time ending:Subtract the time starting: ____How long is your line (in mm)?

Paleozoic:Write down time ending:Subtract the time starting: __ How long is your line (in mm)?

Measure each Eon and draw (with the color marker indicated above) a line across the tape, label each section of tape (with the color marker indicated above name with the proper Eon.

Finally, you need to mark off the Periods that are in the Paleozoic, Mesozoic and Cenozoic. They are (from the top of the paper down):

Cenozoic Today (at the very top of the chart) Quaternary 1.8mm Tertiary 63.2mm

Mesozoic Cretaceous 144 – 65 = 79mm Jurassic 206 –144 = 62mm Triassic 248 – 206 = 42mm

Paleozoic Permian 299 – 248 = 51mm Carboniferous 359 – 299 = 60mm Devonian 416 – 359 = 57mm Silurian 444 – 416 = 28mm Ordovician 488 – 444 = 44mm Cambrian 542 – 488 = 54mm

Keep Geologic Time Scales for lesson 4.

Lesson 3: Stratigraphy

Materials (1 per student): Paper cup – 8 oz Large, transparent, plastic straw (Burgerville has the perfect straws) Homemade of playdoh in 4 different colors (yellow, green, red, blue; recipe for 28

students follows)o 7 c. flouro 7 c. boiling watero 14 tbsp. cream of tartar

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o 3½c. salto 7 tbsp. oilo Red food coloring o Mix and kneed all ingredients until smooth consistencyo Repeat for the other three colors (green, blue and yellow)o Store each color separately in gallon zip-lock baggies

“Fossil” (use can use just about anything small item to represent the fossil for example a button or stone)

Optional wax paper or newspaper to confine the mess

Preparation: Gather materials Make 7 cups of each color of homemade playdoh (each student receives ¼ cup of each

color

Directions: Discuss with the students Steno’s Law of Original Horizontality and the Law of

Superposition. Ask each student to collect 1 cup, 1 straw, ¼ cup of each color of playdoh and 1 fossil. Direct the students to place the blue playdoh into their cup, and press it firmly so that

there are no air bubbles. Direct the student to press the yellow playdoh firmly into their cup on top of the blue playdoh. Direct the students to place their fossil in the red playdoh, and to place the red playdoh into their cup on top of the yellow playdoh. Finally, direct the students to put the green playdoh on top of the red playdoh.

Which is the playdoh that is the oldest – the one first placed into the cup (blue)? Where is it located (on the bottom)?

Which is the playdoh that is the youngest – the last one placed into the cup (green)? Where is it located (on the top)? Which playdoh is older, the yellow or the red?

Ask if the students can see their fossil. Ask the students to take their straw to collect a core sample of their playdoh Earth. In

order to collect their sample, they need to carefully twist their straw back and forth with a thumb and forefinger as pushing slowly down. Direct them to place their cup on their desk and hold it with their non-dominant hand. Direct them to CAREFULLY stab their playdoh. Remove the straw. Inside the straw should be a core of playdoh Earth (maybe with all 4 layers).

Ask the students to rip their cups from the playdoh, being careful not to damage their playdoh. Ask the students to compare their core to the actual layers that were in the cup.

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They will now simulate weathering. Ask half of the students to carefully scrape the green playdoh, as weathering occurs at the surface, working their way to the red play doh until their fossil begins to appear. Ask the other half of the students to break their playdoh in half, through all 4 colors simulating faults in the Earth.

Ask the students if they can see their fossil. Not all students will be able to see it. Discuss that fossils are found by seeing them. It isn’t until the Earth around them erodes, or geologic action (like faulting) brings them to the surface, and then weathers them out.

Lesson 4: Fossils

Please note: The 45-minute allocated time does not include the research portion of this lesson, which is to be assigned as homework starting 5 days prior to this lesson.

Materials (1 set per team of students): Organisms for Geologic Time copy (found below) 20 Index cards Color pencils Markers Computers or library books String, yarn, or ribbon Clear tape If available, fossils of as many of the species listed. If you live close to a university, you

may be able to borrow some of these, or a rock shop may be willing to visit your classroom and bring in some of their fossils to show the students.

Preparation: Gather materials

Directions: Divide students back into their groups of 4-5 from the geologic time line lesson. One week prior to this lesson, students select either 4 of the organisms listed on the

provided handout below. The students research (either with the internet or library books) what these animals looked like, and an interesting fact or two about them as homework.

The students sketch a picture of their organisms on one side of the index card, and on the other side, they write some of the interesting facts they learned about their organisms.

Each student tapes a string, ribbon or yarn on their index card, and attaches the card to the timeline when this organism first appeared in the fossil record.

Using a different color marker for each type of organism, the student draws a line from the first evidence to when they went extinct or all the way to "today" (the top edge of their timeline) if they are still around.

Using the time line on the first page, find out when the first fossils for each of these organisms was found. Then draw a line along the length of your paper from first fossil to either today, or when the animal went extinct.

Organisms for the Geologic Timeline

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Organism First fossils Extant/Extinct Notesbivalves (clams) Cambrian Still alive greatly increased

brachiopods Ordovician Still alive most common fossil, now greatly reduced

crinoid Early Ordovician Still alive only live in deep marine water now

gastropods (snails) Cambrian Still alive greatly increased

horn coral Ordovician Late Permian

sand dollars Ordovician Still alive

sea urchins Ordovician Still alive

tabulate coral Late Cambrian Late Permian

trilobites Early Cambrian Late Permian first metazoan with eyes

ammonite Devonian Cretaceous related to octopus, squid and nautilus

mammal Jurassic Still alive

amphibian Devonian Still alive First fossils had 7 or 8 digits (fingers or toes)!

reptile Carboniferous Still alive Reptiles – currently changing to include birds

bird Jurassic Still alive Included in reptiles

mammal-like reptile

Carboniferous Triassic Almost wiped out in Permian extinction, but were dominant animal during Permian

insects Devonian Still alive Mass extinctions do not seem to impact insects

arachnid Silurian Still alive First terrestrial animal know – scorpion fossil

dinosaur Triassic Cretaceous Dominant animal during most of the Mesozoic

shark Devonian Still alive

fish Cambrian Still alive Jawless fish, most closely related to lampreys and hagfish

Lesson 5: Layers of the Earth

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Materials (1 per student): 1 handout per student markers scissors construction paper drawing compass ruler glue

Preparation: Gather materials

Directions: Discuss that the Earth is comprised of different layers. What we see as our landscape is

thinner than the skin on an apple. Post the measurements of the Earth layers on the blackboard, overhead, or on a piece of

butcher paper. Ask the students what they could do to convert this information into a scale model of the

Earth’s layers. Distribute the markers, construction paper, scissors, drawing compasses, and rulers to the

students.Post the following information

The diameter of the Earth is 12,756 km.Layer Thick Model Notes

Crust 0-35 km 8½” circleMantle 2,890 km 8” circleOuter Core 2,210 km 5½” circleInner Core 2,440 km 2½” circle

o Using the colored construction paper, have each student model the layers of the earth. With the blue sheet, students should measure an 8½" circle for the crust and label it 6-40 miles. The crust is made of many plates that "float" above mantle. The crust is thicker and lighter at the continents and thinner and denser at the ocean floor.

o The brown sheet of construction paper should be used to measure an 8" circle for the mantle and labeled 1,800 miles. The mantle lies below the crust and is a thick layer of solid rock. Many scientists believe that the mantle transfers heat from the core to the surface.

o With the yellow sheet, ask students to measure a 6" circle and label it 1,375 miles. This represents the outer core that is made of melted iron and nickel. It is much denser than the rock layers above it. The temperature of the outer core can range from 4000 to 9000 deg F.

o Use the black construction paper to represent the inner core. Students should measure a 3" diameter circle and label it 1, 750 miles. The inner core is made of

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solid iron and nickel. These materials sank to the center of the earth while it was still in molten form.

Ask the student to calculate the radius of each of the scale of Earth’s layers. Review all of the student calculations to ensure that they are correct.Layer Thick Model Notes

Crust 0-35 km 8½” circle Radius 4.25”Mantle 2,890 km 8” circle Radius 4”Outer Core 2,210 km 5½” circle Radius 2.75”Inner Core 2,440 km 2½” circle Radius 1.25”

Instruct the students to use the drawing compass. First they need to open the drawing compass to the radius of the inner core. (Ask why they open to the radius?)

Instruct the students to draw their circle of the inner core using their compass. Repeat for each of the other layers, using the radial measurements. Instruct the students to cut out each of the circles. Instruct the students to add information about each of these layers on their circles. Instruct the students to glue each of the layers to build their model of the Earth.

Example:

Lesson 6: Plate Tectonics

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Materials (1 per student): 1 handout per student scissors construction paper glue color pencils

Preparation: Gather materials

Directions: Discuss with the students:

o In 1911, Alfred Wegner was struck by the occurrence of identical fossils in geological strata that are now separated by oceans. The accepted explanations or theories at the time posited land bridges to explain the fossil anomalies; animals and plants could have migrated between fixed separate continents by crossing the land bridges. But Wegener was increasingly convinced that the continents themselves had shifted away from a primal single massive supercontinent, which drifted apart about 180 million years ago, to judge from the fossil evidence. Wegener used land features, fossils, and climate as evidence to support his hypothesis of continental drift. Examples of land features such as mountain ranges in Africa and South America lined up; also coal fields on Europe matched up with coal fields in North America. Wegener noticed that fossils from reptiles such as Mesosaurus and Lystrosaurus were found in places that are now separated by oceans. Since neither reptile could have swam great distances, Wegener inferred that these reptiles had once lived on a single landmass that split apart.

o About 250 million years ago, all the continents collided into one supercontinent called Pangaea. We see evidence of that collision today.

Support for the theory of Plate Tectonics is fossil evidence. With a world map, discuss the evidence.

Distribute the map to the students. Instruct the students note the evidence on their map. For example, in northern Brazil and central Africa, label “paleomagnetic stripes mirror each other. In addition, color-code these clues for clarity.

Instruct the students to cut out each of the continents. Direct the students to use their best guesses as to how the continents fit together. The

clues will provide support for their guesses. After everyone tries the best guess, distribute the Pangaea map. How close were they to

the leading hypotheses?

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The Evidence In Support of Plate Tectonics

1. The paleomagnetic stipes or iron crystal patterns in the rocks of northern Brazil and central Africa are mirror images of each other. Color Code: RED

2. There is evidence of glacier activity on both sides of the Atlantic Ocean along the Equator. Color Code: ORANGE

3. Glossopteris is a genus of extinct seed fern (a Pteriosperm) whose fossils are found throughout India, South America, southern Africa, Australia, and Antarctica. Color Code: YELLOW

4. Mesosaurus was one of the first aquatic reptiles. Fossils have been found in South Africa and South America. Color Code: GREEN

5. The age of the rocks in Europe and north America are the same, and get progressively older as you move inland from the ocean. Color Code: LIGHT BLUE

6. Fossils of Lystrosaurus, a mammal-like reptile, are known from Antarctica, India, and Africa. Color Code: DARK BLUE

7. Mountains in Greenland and Norway are almost identical in their geological structure.8. The locations of earthquakes and volcanoes are not random. The occur along the margins

of the crustal plates. Color Code: PURPLE9. The mountains of Scotland and the Appalachian mountains of north Americal are almost

identical in their geological structure. Color Code: Gray10. The geological structure of southern Senegal and the Amazon Basin are almost identical.

Color Code: PINK

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Instructions:1. Color code the 10 clues that support the theory of plate tectonics.2. Cut out each of the 7 continents.3. Arrange each of the continents based on three lines of evidence:

a. How the continents look todayb. The shape of each of the continentsc. The 10 clues.

4. Examine Dr. Scotese’s map of the Permian. How close were you?5. If you need to, rearrange your continents to the current hypothesis, and glue them to a

piece of paper.

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Lesson 7: Plate Boundaries

Materials (1 set per group): Foam mattress cut into wedges as depicted below. You only need to cut 3 shapes. For

diagram D, you can use the two flat sides of your polygons. blue paper cardboard box scissors (or craft knife) color pencils or markers

Preparation: Cut foam mattress into the 3

defined shapes pictured to the right.

Cut box as pictured below Gather all materials.

Directions: Discuss that as the continents

move, that causes the continental plates to do one of three things, move apart, crunch together, or grind past each other. This lesson, students will be building 2 different models of these boundaries.

Distribute the prepared boxes. Direct students to take two sheets of blue paper to represent the oceanic plate. On both sheets place a triangular tube to represent the plate with an oceanic and continental crust. (Brown cardboard works well.)

Place the unattached sides of the papers through the slit so that only about half of the paper is showing. Direct the student to reach in the opening on the side and slowly move the paper. When one paper is pulled down, this represents the convergence of the plates. When the paper is pushed up, this represents the divergence of the plates.

Move only the sheet with the cardboard attached so that the cardboard comes to the edge of the slit. This represents the ocean plate disappearing beneath the edge of the continent. This is called subduction. This sinking of the oceanic plate into the mantle below the edge of the

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continental crust results in "plate-pull" and may be one of the major forces driving plate tectonics. Subduction also results in volcanic eruptions and very deep ocean trenches.

On the plain sheet of blue paper, attach another triangle so that this also has a continental and an oceanic crust. Now pull both sheets of blue paper from the bottom. If you do this carefully, one of the triangles will go on top of the other showing the development of mountains when convergence occurs.

If the layers are moved toward the sides of the box, the students can see the action of fault lines moving in an earthquake. This is called a transform fault.

For the next demonstration, students can work in groups of 2. Hand one set of the 3 foam polygons the partners.

Working together, the students simulate the plates moving together (convergence), forcing the wedge up. Ask the students to remove the wedge, and one student turn their polygon over. Try this again. Note that one wedge is on top, and the other is force beneath it.

Working together, ask the students to simulate the plates moving apart (divergence), and the wedge drops down. However, this thins the crust, and instead of getting a depression, there is magma upwelling underneath the wedge. Direct one student demonstrate this by their hand simulating magma, and gently pushing the wedge up higher than the two polygons.

Working together, ask the students to simulate the plates grinding past each other (transform boundaries). The students will need to push both turn their polygons around, using the flat sides. Direct the students to stand facing each other and gently press the foam towards each other. Ask the student to move their foam to the right, which should cause the foam pieces to travel in opposite directions.

Lesson 8: Rock Cycle

Materials (1 set per group of 4 students): Multicolor mini-marshmallows Plastic wrap – 4 pieces White frosting Plastic knife

In addition, set aside: Pan and hot plate (or electric skillet)

Preparation: Gather all materials.

Directions: Discuss the rock cycle. To demonstrate it, direct all students to wash their hands with soap and warm water. Distribute the plastic knife, color marshmallows and frosting to groups of students

(generally 4 students can easily share one can of frosting). Give a piece of wax paper and a piece of plastic wrap to each student as a work surface.

Sedimentary rock is made by pieces of metamorphic, sedimentary, or igneous rock (weathered into smaller and smaller particles) and then cemented together with minerals. To represent sedimentary rock, direct the students to make two layers of marshmallows, and each layer is a total of 8 marshmallows. Students will need 16 marshmallows total.

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To represent the minerals that cement the smaller pieces together, the students will use the white frosting. BE SURE TO TELL THE STUDENTS THAT THIS SHOULD BE DONE ON TOP OF THE PLASTIC WRAP.

When the students have completed their sedimentary rocks, they will model metamorphic rock. This rock is formed through pressure and heat. It can be metamorphic, sedimentary, or igneous rock. To simulate this, direct the students to loosely wrap their marshmallow in the plastic wrap. The heat and pressure will come from their hands. Have them squish their marshmallow between their hands while you continue to discuss the rock cycle with them. This may take a bit of time, and their arms may get tired. Give them a break, and then back at it. Just like metamorphic rock, it doesn’t happen in a second, or a minute. When the marshmallows squish and stick together, you have completed the metamorphic stage.

To demonstrate igneous, those metamorphic rocks get buried, however igneous rock can be metamorphic, sedimentary, or igneous rock. As it gets buried further down, it melts, and becomes igneous rock. To demonstrate igneous, direct the students to bring you their marshmallows. Place them in the pot or electric skillet, and melt them. If you do this over low heat, you will see spots of different colors. When the marshmallows have melted, place them in the freezer overnight.

The remaining step will be conducted on the next lab.

Lesson 9: Minerals

Materials (1 set per student): Three clear plastic cups (short and wide are better than tall and thin) 1 pint canning jar Distilled water 3 craft sticks Epsom salts Black construction paper Scissors Pipe cleaner Borax Pencil String Mrs. Stewart’s bluing Ammonia Table salt Food coloring Charcoal briquettes Hand lens

In addition, set aside Hot plate and pot or other method of making hot water Pot holder

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Preparation: Gather all materials.

Directions: Students will make 3 crystal recipes using different minerals. When the crystals have

grown, they will examine the crystals and classify them according to their crystalline structure.

Recipe #1: o Use the scissors to cut black construction paper so that it will fit in the bottom of the

cup, and put it in the bottom of the cup.o In another cup, add 1 teaspoon of Epsom salt to 1 tablespoon of very warm water. Stir

with the craft stick until the salt is dissolved.o Pour the salt solution over the paper.o Put the cup in the place where it will remain undisturbed.o Rinse out your mixing cup.

Recipe #2 (conduct this experiment in the morning. Check results before going home.)o Cut a pipe cleaner into three equal sections. o Twist the sections together at their centers to form a six-sided shape. The pipe cleaner

should fit inside the jar, but not touch the bottom. o Tie the string to the end of one of the arms. Tie the other end of the string to the

pencil. You want the pipe cleaner to hang into the jar, but not all the way to the bottom.

o Add 1 cup of boiling water to the jar.o Add 3 tablespoons borax to the water. It is okay if some undissolved borax settles to

the bottom of the jar. o Add food color. o Hang the pipe cleaner snowflake into the jar so that the pencil rests on top of the jar

and the snowflake is completely covered with liquid and hangs freely (not touching the bottom of the jar).

o Allow the jar to sit in an undisturbed location during the day or overnight. o Allow the crystals to continue to grow.

Recipe #3 (this one will not be visible right away, and your students will need to revisit it later)o Place chunks of your charcoal briquette in an even layer in the bottom of your cup.

You will need smaller pieces (largest about 1-inch in diameter), so use a hammer to break the material.

o Sprinkle distilled water, onto the briquette until is has been thoroughly dampened. Pour off any excess water.

o In an empty cup, mix 1 tablespoons uniodized salt, 1 tablespoons ammonia, and 2 tablespoons bluing. Stir until the salt is dissolved.

o Pour the mixture over the briquette.o Add and swirl a bit of water around in the empty jar to pick up the remaining

chemicals and pour this liquid onto the substrate, too.

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o Add a drop of food coloring here and there across the surface. Areas with no food coloring will be white.

o Sprinkle more salt (about 1 T or about 30 ml) across the surface.o Set the cup in an area where it will not be disturbed.o On days 2 and 3, pour a mixture of ammonia, water, and bluing (1 tablespoon) in the

bottom of the pan, being careful not to disturb the delicate growing crystals.o Keep the pan in an undisturbed place, but check on it periodically.

After the crystals have grown, give each student a piece of black construction paper and a hand lens. Students will now classify what category each crystal belongs.

There's more than one way to categorize a crystal! The two most common methods are to group them according to their crystalline structure and to group them according to their chemical/physical properties. We will be using the crystalline structure.

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Crystalline Shapes

Using your hand lens, determine what shape your crystals have.

Cubic or Isometric - not always cube shaped! You'll also find octahedrons (eight faces) and dodecahedrons (10 faces).

Tetragonal - similar to cubic crystals, but longer along one axis than the other, forming double pyramids and prisms.

Orthorhombic - like tetragonal crystals except not square in cross section (when viewing the crystal on end), forming rhombic prisms or dipyramids (two pyramids stuck together).

Hexagonal - six-sided prisms. When you look at the crystal on-end, the cross section is a hexagon.

Triclinic - usually not symmetrical from one side to the other, which can lead to some fairly strange shapes.

Monoclinic - like skewed tetragonal crystals, often forming prisms and double pyramids.

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Lesson 10: RocksModified from: http://geology.about.com/od/rocks/tp/rocks101.htm

Materials (1 set per group of students): Rocks 1 or 2 of each of the following:

o Igneouso Metamorphico Sedimentary

Hand lens White unglazed ceramic tile Black unglazed ceramic tile Paper clip Penny Nail HCl (dilute solution) Magnet Water 100 ml graduated cylinder Scale or balance Copies of

o Rock Sorting Student Directions o Student Data Collection Sheeto Words List

Preparation: Gather all materials. Divide students into teams Distribute

o supplieso Rock Sorting Student Directionso Student Data Collection Sheeto Rock Description “Words List”

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Rock Sorting Student Directions:1. Sort the rocks into groups based on any characters you and your lab partners

choose. Record how you group your rocks.2. Select different characteristics, and sort the rocks. Record.

a. Do you think one way of classifying is more informative than the other? 3. Rocks get dirty and decay: wind and water make every kind of rock slowly

break down, the process called weathering. You want to observe fresh. Now take out your magnifier. Find good light and examine the rock's fresh color. Overall, is it dark or light? What colors are the different minerals in it, if those are visible? What proportions are the different ingredients? Sketch the rock on the reverse side of your data collection sheet.a. –Color:

i. –Draw a line on the white streak plate and record the color(s) of the streak

ii. –Draw a line on the black streak plate (if available) and record the color(s) of the streak

iii. –Dampen rock and record color(s)b. –Luster: How does the rock reflect light? Is it:

. –Glassy vitreous – shines like glass

. –Earthy, chalky – dull

. –Metallic – looks like metal

. –Waxy, silky, pearly – has muted shine4. Some rock characteristics are the weight/volume (specific gravity), and if the

rock is magnetic.a. –Specific Gravity: What is the mass in grams?

. –Mass the rock in grams

. –Use the graduated cylinders to find the volume of the rock (record the volume of water before adding the rock, and after adding the rock. The difference is the volume of the rock.

. –Calculate (HOORAY, MATH!!!) g/ml

. –Example: 12.3g/3.1ml = 3.97g/mlb. –Magnetic: Is the rock magnetic or do magnets stick to it?

. –Does a paperclip stick to the rock? Record result.

. –Does the magnet stick to the rock? Record result.5. For a chemical reaction analysis, you can use your sense of smell, and a dilute

Hydrochloric Acid.a. –Smell: How does the rock smell?:

i. –Earthyii. –Sour

iii. –Sweet

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iv. –Rotten eggishv. –Other

b. –Chemical: Does HCl react?i. Add a drop and observe. Record the results

6. Observe the rock's texture, close up. What kind of particles is it made of, and how do they fit together? What's between the particles? This is usually where you may first decide if your rock is igneous, sedimentary or metamorphic. The choice may not be clear. Observations you make after this should help confirm or contradict your choice.

a. Igneous rocks cooled from a fluid state and their grains fit tightly. Igneous textures usually look like something you might bake in the oven.

b. Metamorphic rocks are rocks of the first two types that were changed by heating and stretching. They tend to be colored and striped.

c. Sedimentary rocks consist of sand, gravel or mud turned to stone. Generally they look like the sand and mud they once were.

7. Observe the rock's structure, at arm's length. Does it have layers, and what size and shape are they? Do the layers have ripples or waves or folds? Is the rock bubbly? Is it lumpy? Is it cracked, and are the cracks healed? Is it neatly organized, or is it jumbled? Does it split easily? Does it look like one kind of material has invaded another?

a. –Feel: When you touch it, does it feeli. –Gritty or sandy

ii. –Powdery, earthy, or chalkyiii. –Smooth like glassiv. –Smooth and sticky or waxyv. –Sharp and metallic

8. Mohs Test of Hardness is the last important set of observations. You need your fingernail, a penny, and a nail.

a. Using your fingernail, can you scratch the rock? If so, stop here and record.

b. Using a penny, can you scratch the rock? If so, stop here and record.c. Using a nail, can you scratch the rock? If so, stop here and record. This is

a quick and simple version of the 10-point Mohs scale of mineral hardness: nail is usually hardness 5-1/2, coins are hardness 3, and fingernails are hardness 2.

d. Be careful: a soft, crumbly rock made of hard minerals may be confusing. If you can, test the hardness of the different minerals in the rock.

9. After completing these different assessments, use this information to sort your rocks one more time.

a. Is it different than your first time? In what ways is it different?

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Student Data Collection SheetCharacter Rock 1 Rock 2 Rock 3

Color

White Streak Plate color

Black Streak Plate color

Luster

Specific Gravity (g/ml)

Paper clip sticks to rock?Magnet sticks to the rock?

Smell

Rx with acid?

Igneous, Metamorphic,

or SedimentaryFeel

Hardness - fingernailHardness -

pennyHardness - nail

Sketch of Rock #1:

Sketch of Rock #2

Sketch of Rock #3

Rock Description “Words List”Colors

white colorless clear beige dirty-white

red purple mauve pink salmon pink

blue bluish turquoise green silvery -yellow

gray silver black golden gold-colored

yellow bronze brown creamy copper-colored

Other words to describe colors

deep shiny dull dark very dark

light pale bright    

splotchy streaked layered speckled banded

Luster

Word Description Example

dull / earthy very dull, mainly in minerals that are porous kaolinite, orthoclase

waxy 

opal, chalcedony

greasy / oily 

nepheline

pearly like a pearl, play of colours, light talc, some micas

silky 

some varieties of gypsum, kernite, ulexite & in fibrous minerals

glassy / vitreous

looks like glass quartz, many rock-forming mineralsobsidian – "nature’s glass"

resinous looks like freshly-broken shellac, usually yellow-brown

sphalerite

adamantine high lustre, almost brilliant sphalerite

submetallic silvery or metallic lustre but mineral is transparent or translucent when in small slivers

hematite

metallic highly reflective, opaque minerals pyrite, gold, silver

Other words that describe luster

shiny sparkles milky shimmering opalescent

frosted       

Transparancy

transparent clear, see right through it when it is sliced thin

- quartz crystal, celestite, selenite

translucent see shapes & shadows through it when it is sliced thin, chemical impurities can cause the mineral to be cloudy - calcite, quartz,

sphalerite

opaque can’t see light through it at all when it is sliced thin - metals, gypsum

Specific Gravity

Description SG Mineral examples

very light < 2 borax

light 2 – 3 quartz, calcite, halite, dolomite, ulexite, gypsum, turquoise, talc, muscovite, biotite

heavy 3 – 5 barite, chalcopyrite, fluorite, celestite, apatite, almandine garnet

very heavy 5 – 10 nickel-iron, galena, pyrite, magnetite

extremely heavy > 10 silver, gold

Other

Reaction with Acid Yes? Calcium carbonate

Magnetic Yes? Magnitite

Moh's Scale of Hardness

Rating Description Mineral example

1 SOFT Easily crumbles. Can be scratched with a fingernail (2.2). Talc

2 Can be scratched with a fingernail (2.2). Gypsum, Soapstone (impure talc)

3 Can be scratched with a copper penny (3.5). Calcite

4 Can be scratched with a common nail. Fluorite

5 Can be scratched with a piece of glass (5.5). Apatite

6 Mineral of hardness 6 or more will scratch glass. Feldspar, Orthoclase

7 Quartz

8 

Topaz

9 

Corundum

10 HARD 

Diamond

Week 3 – Scientific MethodSuggestion

http://chemistry.about.com/cs/sciencefairideas/a/aa072903a.htm

Growing crystals is a fun way to explore your interest in chemistry and geology. There are lots of types of crystals that can be grown from common household substances, such as sugar (sucrose), salt (sodium chloride), Epsom salts, borax, and alum. Sometimes it's interesting to mix different materials to see what types of crystals result. For example, salt crystals look different when they are grown with vinegar. Can you figure out why?

If you want a good science fair project, it would be better if you tested some aspect of growing crystals rather than simply growing pretty crystals and explaining the process. Here are some ideas of ways to turn a fun project into a great science fair or research project:

How does the rate of evaporation of the crystal-growing medium affect the final size of the crystals? You can change the rate of evaporation by sealing the container (no evaporation at all if there is no air space) or by blowing a fan over the liquid or enclosing the jar of medium with a dessicant. Different places and seasons will have different humidities. The crystals grown in a desert may be different from those grown in a rain forest.

You will usually heat water or another liquid to dissolve a solid to grow your crystals. Does the rate at which this liquid is cooled affect the way the crystals grow? You can compare crystals allowed to cool at room temperature to those formed from cooling the liquid in a refrigerator.

What effect do additives have on the crystals? You could add food coloring, flavorings, or other 'impurities'. How do crystals grown from uniodized salt compare with those grown from iodized salt?

What steps can you take to maximize crystal size? Developing a procedure is a form of experimental science. You can affect parameters such as vibration, humidity, temperature, rate of evaporation, purity of your growth medium, and time allowed for crystal growth. The type of container used to grow your crystals may make a difference, as could the type of string used to suspend a seed crystal (or other method used to grow a crystal). Are you changing containers when crystals start to grow that could compete with your seed crystal? There are lots of things to think about! Some may have a major effect on crystal growth and others may be negligible. Does light/dark affect growth? Probably not for a salt crystal, but it could for a substance that is degraded by visible radiation.

If you are up for a challenge, you can make predictions about the shapes of crystals before you grow them, based on their molecular structures and molecular geometry.