Clues from the Landscape Social Studies Lesson 1 Becoming a Homesteader is designed to be used with Clues from the Landscape Artifact Kit. Lessons 1, 2 and 4 can be completed without the artifacts from the kit. These kits are available through Musuems of Western Colorado to D51 Teachers. This lesson can be adapted to use without the kit. Students will be able to: • Describe the requirements for homesteaders under the Homestead Act of 1862 • Discuss the hardships faced by homesteaders • Defend their decision whether or not they would choose to become homesteaders.

Students will analyze a variety of county-level census data, including on employment, technology, and transportation, in histograms to compare and contrast the shapes of their distributions and to interpret measures of center and spread in context.

In this activity students learn how Earth's energy balance is regulating climate. This activity is lesson 4 in the nine-lesson module Visualizing and Understanding the Science of Climate Change.

Western Mining History presents a brief summary of The Colorado Gold Rush with links to additional Colorado information pages. Western Mining History is an historical site that provides databases, information on mining, mining towns, gold and Photos and maps of the western United States. Consider becoming a member or making a donation to help further the work of the site.

How do greenhouse gases affect the climate? Explore the atmosphere during the ice age and today. What happens when you add clouds? Change the greenhouse gas concentration and see how the temperature changes. Then compare to the effect of glass panes. Zoom in and see how light interacts with molecules. Do all atmospheric gases contribute to the greenhouse effect?

In this problem-based learning module, students research and report on Hurricane Katrina, using an earth systems science analysis approach.

In this activity, students use maps and data to learn about where and how hurricanes form and possible correlations with climate change affecting their strength.

Western Mining History presents a short tour of tent towns from the frontier west during the gold and silver rush. The resources shows Photos of miner's cabins and living conditions. Western Mining History is an historical site that provides databases, information on mining, mining towns, gold and Photos and maps of the western United States. Consider becoming a member or making a donation to help further the work of the site.

This is a sequence of 5 classroom activities focusing on the El Niño climate variability. The activities increase in complexity and student-directedness. The focus of the activities is on accessing and manipulating real data to help students understand El Niño as an interaction of Earth systems.

This exercise set explores marine sediments using core photos and authentic datasets in an inquiry-based approach. Students' prior knowledge of sea floor sediments is explored in Part 1. In Parts 2-3 students observe and describe the physical characteristics of sediment cores and determine the composition using smear slide data and a decision tree. In Part 4 students develop a map showing the distribution of the primary marine sediment types of the Pacific and North Atlantic Oceans and develop hypotheses to explain the distribution of the sediment types shown on their map.

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Linking Value Chains. This is the Lesson 2 Understanding Colorado Agriculture activity from Unit 6 Food Products and Processing, from the DIGS (Developing Individuals, Growing Stewards) AmeriCorps Curriculum from CSU. The curriculum focuses on introducing students in grades 3-5 to Colorado agriculture, industry and environmental issues. The curriculum is matched to State Standards 2021. The curriculum upon request. Visit: https://engagement.colostate.edu/programs-old/developing-individuals-growing-stewards/

In this activity from NOAA's Okeanos Explorer Education Materials Collection, learners investigate how methane hydrates might have been involved with the Cambrian explosion.

Show Caption
Hide This diagram shows the relationship of Gibbs Free Energy to composition. In this diagram there are two minima represented for free energy which is achieved by unmixing of two distinct phases each with definite composition. The dashed line, which is tangential to the two minima in the free energy curves, gives the composition of the coexisting minerals at a specific temperature. From: Klein, C., and Dutrow, B., Manual of Mineral Science, 23rd ed., J. Wiley and Sons. Used with permission. The phenomenon of solid solution is common in many rock-forming minerals. At high temperatures, thermal vibrations permit accomodation of ions with size differences on the order of 15-30%. However, as physical conditions change, ions no longer fit into similar sites which creates internal (lattice) strain energy. Consequently, the mineral composition must adjust to relieve this strain energy and minimize the Gibbs Free Energy of the system. One possible response of the system is for elements in a crystal to move from one chemical site to another via intracrystalline diffusion. This results in segregated domains that are enriched in one element or another--this is a process called exsolution.
A good example of this process can be seen in the alkali feldspar mineral group. At high temperature the mineral anorthoclase (K,Na)AlSi3O8 shows complete solid solution, i.e. there is a random distribution of K and Na in the alkali sites of the crystal. Upon cooling, Na and K segregate into more ordered domains creating areas that are rich in albite NaAl Si3O8 and microcline KAlSi3O8(see Figure 1).
The purpose of this exercise is to provide a number of activities to demonstrate how exsolution works and to demonstrate complex-system behavior in this relatively common natural phenomenon.

Part I: Images of naturally occurring perthite.
The following images show minerals that have undergone exsolution at different scales. The image on the top left shows exsolution as viewed with a Transmission Electron Microscope (TEM; field of view is 10 microns). The image on the top right is a photomicrograph of exsolution in microcline as seen in thin section (cross-polarized light, field of view is 2 mm). The picture on the bottom left is a hand sample of perthitic microcline as seen in hand sample (field of view is 10 cm). The picture on the bottom right is a picture of plagioclase feldspar showing the "schiller" effect. This is caused by sub-microscopic unmixing of two distinct plagioclase phases in the compositional range of labradorite (An50 - An70) which results in the beautiful play of colors seen in this photo; (field of view of 20 centimeters). This series of pictures is a good example of scale invariance of this physical phenomenon.
Examine perthite textures from hand samples and thin sections from your own mineralogy collection. We can easily envision unmixing of two immiscible fluids--for example oil and vinegar salad dressing. The same thing happens when we unmix (i.e. exsolve) solid phases--the process just takes a bit longer as atoms have to migrate in the crystal lattice by intracrystalline diffusion! How can such a common feature as perthite be understood in terms of complex-system behavior?

Exsolution observed on a sub-microscopic scale in this TEM picture; this microstructure shows unmixing of labradorite in very fine essentially parallel lamellae. From Champness, P.E., and G.W Lorimer, 1976. Exsolution in silicates. Chapter 4.1 in Electron Microscopy in Mineralogy. H.R. Wenk, ed. Springer-Verlag, New York. Field of view is 10 microns.

Perthite observed in thin section. Field of view is 2 mm.

Perthite observed in hand sample. Field of View is 10 cm.

Unmixing of parallel lamellae, as observed in a hand specimen of labradorite from Madagascar. These lamellae act as diffraction grating for white light, producing spectral colors known as labradorescence or the "schiller effect"; the field of view is 20 cm. Photo by B. Dutrow; used by permission.]

Part II: Exsolution Puzzle Exercise.
This exercise is done in groups of 2-3 students. Coins are initially randomly distributed on a chessboard, and are then subsequently moved to create domains of increasing order (regions that are dominated by either pennies or nickels). This is a kinesthetic learning exercise that creates a physical model that simulates how the exsolution process works. (Inspired by Greg Marfleet, Carleton College)

Randomly distribute 20 pennies and 20 nickels on the attached 7x7 chessboard (Microsoft Word 33kB Dec1 10). The random distribution of pennies and nickels is analogous to the random distribution of Na and K in the high temperature alkali feldspar, anorthosite. (See Figure 1)
The goal is to have a given coin completely surrounded by similar neighbors (i.e. 8 nearest neighbors of the same type of coin located on adjacent edges and the diagonal squares. Each student will sequentially move a coin into an adjacent open position (horizontal, vertical and diagonal moves are allowed) to achieve this desired configuration. Perfect ordering of nickels and pennies into discrete domains is analogous to perfectly ordered crystals of albite and microcline. [NOTE: in this exercise we are modeling the diffusivity of only the alkali elements, Na and K. The ordering of Si and Al in the tetrahedral sites of a feldspar crystal is a related, but entirely different process].
Systems tend to minimize Gibbs Free Energy (see Figure 2) on their way towards a state of equilibrium. In this example, the surface area surrounding domains of the segregated compositions (nickels/Na and pennies/potassium) is proportional to the excess Gibbs Free Energy of those domains. As clusters of similar coins evolve (segregate) and get bigger, the bounding surface areas are minimized and the energetics of the system are decreased.

INSTRUCTIONS

For the initial random state, determine the area surrounding each type of element; do this by assuming the unit length along each edge is 1 and add all the surfaces surrounding Na/nickel and K/potassium coins or aggregates of coins. Count any edges that are not adjacent to another similar coin (i.e. count all nickel-penny interfaces, and any edge where a nickel or penny is adjacent to an open space. Do not count the external edges on the outer border of the chessboard).
Make 10 moves of the coins (always moving into an adjacent open space either right, left, up, down, or on a diagonal) and again determine the bounding surface areas. Record these surface area values for pennies and nickels. Repeat after 20, 30, 40, 50, and 100 moves.
After each set of moves, report your surface area measurements for both pennies and nickels to your instructor; record these values on a spread sheet for later plotting and analysis.
This part of the exercise should take about 45 minutes to complete the sets of movements and measurement of the surface areas.

Here is an example experiment showing the progressive ordering of pennies (potassium) and nickels (sodium). Show pictures of the 2-D distribution of pennies and nickels after 10,20, 30, 40, 50 and 100 successive moves
Hide

Original random distribution of coins.

Distribution of coins after 10 moves.

Distribution of coins after 20 moves.

Distribution of coins after 30 moves.

Distribution of coins after 40 moves.

Distribution of coins after 50 moves.

Distribution of coins after 100 moves; perfect order.

Plot your results. Assume that each move requires 1 unit of time.

Plot your data on a X-Y plot with surface area on the Y axis and time on the X-axis. What is the distribution of your data? (Try plotting data for pennies, nickels, their sum, and their averages). Create a "best fit" curve through the data as plotted on this X-Y diagram (easily done with functions programmed into Excel). . What type of mathematical function is represented by a curve that has a steep slope to begin (left side of the plot), and becomes asymptotic to the X-axis away from the origin? Did you notice that the first set of coin moves produced the largest change in surface area, and that subsequent sets of moves produced smaller and smaller changes to the surface area?
Have you seen other plots with similar profiles from your other studies in Earth Science?
Show Answer:
Hide radioactive decay; longitudinal profile of rivers.... It appears that many processes in Earth Science may follow the same mathematical laws.
Now plot your data on a log-log plot with surface area on the ordinate (Y-axis) and time on the abscissa (X-axis). Create a "best fit" curve through these data (easily done with functions programmed into Excel). What is the shape of this curve? Does this relationship demonstrate a) an exponential function? b) a power law?
Here is an example dataset (Excel 74kB Dec1 10) for 12 experiments completed by the spring 2010 Mineralogy class at Montana State University. Raw data and corresponding graphs are presented in the attached spreadsheet file. Compare your results with those shown in this example exercise.

Intracrystalline Diffusion and Fick's Law
The rate of transport of mass (and energy) through a fixed medium can be described mathematically by Fick's Law of Diffusion. Show details about Fick's Law of Diffusion
Hide.
The fundamental expression of Fick's First Law of Diffusion can be written as:

J = -D( -- c/ -- x)

Jis the flux of a material along a compositional gradient (e.g. mol / length2time1 ), the amount of material (e.g. atoms or moles) that will flow through a small area during a fixed time interval.
Dis the diffusion coefficient (length2 time -1);
c is the concentration (amount of material per volume, mol/m3), and
x is the length (m)
Fick's Law shows that the flux of an ion diffusing through a stationary medium (like the crystalline lattice in our example) is proportional to the concentration gradient ( -- c/ -- x). As diffusion proceeds, the concentration is always changing, and thus, the flux is always changing. Can you see why this process exhibits non-linear behavior and must be represented as a power law?
Note that The diffusivity, D, scales with temperature:

D ~ (kT/h) exp(-Q*/RT)

where k is Boltzmann's constant, h is Planck's constant, and Q* is an activation energy. This means that the rate of diffusion decreases with temperature. Consequently, exsolution will ultimately grind to a halt as temperature decreases. This is why we can observe perthite development in alkali feldspars in a wide variety of igneous and metamorphic rocks...the perthite texture gives us information about the cooling history of the mineral up to a point, but then exsolution will slow to a stop and the perthite will continue to exist in a metastable state at the surface of the earth.
Different types of diffusion pathways include: intragranular (volume) diffusion, grain boundary diffusion, diffusion in a bulk fluid, and diffusion related to crystal defects. In our example of perthite exsolution, intragranular (volume) diffusion is the operative process. This process is most effective at high temperatures.

Note that generally material tends to move in a direction from high to low concentrations, and thus, compositional gradients tend to be minimized by diffusion. However, in the case of exsolution and perthite development during cooling of a high-temperature, homogeneous alkali feldspar (anorthite), just the opposite effect happens--segregated domains of albite and microcline become more stable at lower temperatures. Why is this the case? The answer lies in the overall energetics of the system. It turns out that lattice strain that is induced upon cooling of anorthite results in large excess energy in the system. To minimize this excess energy, a single homogeneous grain of anorthite (stable at high temperature), will undergo "spinodal" decomposition upon cooling. This results in two energy minima, one for each phase, as illustrated in Figure 2. Upon further cooling, these energy minima continue to separate, thus resulting in two stable phases whose compositions increasingly approach the end member compositions of albite and microcline. A more complete description of this process can be found in Chapters 5 and 7 of Putnis A. and McConnell J.D.C. Principles of Mineral Behaviour 258pp. Blackwell Scientific Publications. Oxford. 1980.
Part III: Computer Simulation

Model output from the NetLogo "segregation"program; 2000 objects achieved 70% similarity.The computer program NetLogo can be used to model complex system behavior. This computer program was developed by Uri Wilensky (1999) at the Center for Connected Learning and Computer-Based Modeling, Northwestern University. Evanston, IL. For this exercise, we will use the pre-programmed function for Segregation

Experiment with this program by changing the input parameters to try to reproduce a) the pattern you developed in the puzzle model above, and b) perthite patterns observed in the natural microcline crystals.

Part IV: Visualization of the Development of Exsolution

The binary solvus phase diagram for the alkali feldspar system at low pressure. Figure provided by Dexter Perkins, used with permission.The binary "solvus" phase diagram (showing the relation of temperature to composition) is typically used to show the phase relations for alkali feldspars. A single homogeneous alkali feldspar occurs at high temperatures (Figure 1a), but as the system cools eventually the phase boundary (solvus) is intersected and the exsolution (unmixing) process begins. "Underneath" the solvus a single feldspar is no longer thermodynamically stable, and the system begins to separate into two phases that become increasingly Na-rich or K-rich upon further cooling. This visualization demonstrates the cooling history of an alkali feldspar, including use of the "lever rule" to calculate phase composition (mineral) and relative proportions. Examine the accompanying illustrations and track the "state" of the system as temperature changes. Binary Solvus for the Alkali Feldspar System. The accompanying illustrations on the right show the "state of the system" in terms of the relative proportions of the phases present for each assigned temperature.
Relate these products and processes to natural occurrences of perthite, and think about the changes that have to take place on the atomic scale to produce the mesoscopic features that are visible in hand samples.

Part V: Thought Questions

Driving forces: in equilibrium thermodynamics, the system always drives towards the lowest Gibbs Free Energy. At equilibrium, chemical potential is zero. This typically means there are no compositional gradients. Why does this system drive towards segregated domains that are rich in Na and K?
Consider entropy "in the system". What do we mean by "the system"?
Refer to Ilya Prigogine's (winner of the 1977 Nobel Prize for Chemistry) classic work on this subject: Order out of Chaos, Man's New Dialogue with Nature (1984, Bantam Books, 394 pp.)

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This module is focused on increasing the users understanding and familiarity with the fate and transport of contaminants. Video clips of sand tank models showing the movement of contaminants in subsurface porous media are included. The sand tank models provide a visual guide to help see how different geologic materials with different permeability's effect the movement of fluids and ultimately the distribution of contaminants.

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In this curriculum module, students in high school life science, marine science, and/or chemistry courses act as interdisciplinary scientists and delegates to investigate how the changing carbon cycle will affect the oceans along with their integral populations.

The oceans cover 70 percent of the planet and play a critical role in regulating atmospheric carbon dioxide through the interaction of physical, chemical, and biological processes. As a result of anthropogenic activity, a doubling of the atmospheric CO2 concentration (to 760 ppm) is expected to occur by the end of this century. A quarter of the total CO2 emitted has already been absorbed by the surface oceans, changing the marine carbonate system, resulting in a decrease in pH, a change in carbonate-ion concentrations, and a change in the speciation of macro and micronutrients. The shift in the carbonate system is already drastically affecting biological processes in the oceans and is predicted to have major consequences on carbon export to the deep ocean with reverberating effects on atmospheric CO2. Put in simple terms, ocean acidification is a complex phenomenon with complex consequences. Understanding complexity and the impact of ocean acidification requires systems thinking – both in research and in education. Scientific advancement will help us better understand the problem and devise more effective solutions, but executing these solutions will require widespread public participation to mitigate this global problem.

Through these lessons, students closely model what is occurring in laboratories worldwide and at Institute for Systems Biology (ISB) through Monica Orellana’s research to analyze the effect CO2 has on ocean chemistry, ecosystems and human societies. Students experiment, analyze public data, and prepare for a mock summit to address concerns. Student groups represent key “interest groups” and design two experiments to observe the effects of CO2 on seawater pH, diatom growth, algal blooms, nutrient availability, and/or shell dissolution.

Trail Guide for hiking trail near where important fossil finds occured in Western Colorado. When visiting these trails it is important to visit with respect by staying on the trail and leaving fossils where you find them. These fossils and tracks are protected under the Paleontological Resources Preservation Act (PRPA) of 2009. The act prohibits an attempt to excavate, remove, damage, or otherwise alter or deface any paleontological resources located on Federal land. In order to collect any fossils (plants, invertebrates, vertebrates) at these sites, a proper permit must be obtained. If you are interested in excavating fossils with our scientists at Dinosaur Journey, check out our Dinosaur Digs and Expeditions! https://museumofwesternco.com/things-to-do/dino-digs/

This activity introduces students to stratigraphic correlation and the dating of geologic materials, using coastal sediment cores that preserve a record of past hurricane activity.

Acting as civil engineers hired by the U.S. Department of Transportation to research how to best use piezoelectric materials to detect road damage, student groups are challenged to independently create their own experiment procedures, working with given materials and tools. The general approach is that they set up model roads using rubber mats to simulate asphalt and piezoelectric transducers to simulate the in-ground road sensors. They drop heavy bolts at various locations on the “road,” collecting data and then analyzing the voltage changes across the piezoelectric transducers caused by the vibrations of the bolt hitting the rubber. After making notches in the rubber “road” to simulate cracks and potholes, they collect more data to see if the piezo elements detect the damage. Students write up their research and conclusions as if presenting evidence to USDOT officials about how the voltage changes across the piezo elements can be used to indicate road damage and extrapolated to determine when roads need maintenance service.

Engineers work in many fields associated with precipitation. Engineers study glaciers to better understand their dates of formation and current demise. They deal with issues of pollution transport and water yield, and they monitor reservoirs and dams to prevent flooding.

To prepare for this lab activity, there are several preceding lectures on the basics of the hydrologic cycle, river systems, and sediment transport. We also introduce the watershed, including city maps of the land use in the area of the creek. Students read the relevant chapter in the textbook beforehand. Students collect the field data from the stream during the first week, and the second week focuses on teaching them to analyze the data, and to use spreadsheets to graph their results. A very detailed, formal report is handed in by each student at the culmination of the project.

The field experience requires students to collect and analyze data from four different stations along a local, impacted creek system. At each location students measure velocity and cross-sectional area, which they use to calculate the stream discharge. Students also collect data on the sediments by sieving and weighing samples, which they later use to generate cumulative sediment distribution curves. Water quality collected at each site includes total coliform, turbidity, nitrate concentrations, pH, dissolved oxygen, and temperature. Students are required to discuss all of these factors in their final report, and to assess whether the data are 'as expected' from the lectures and the reading. In addition, students develop and test their own hypothesis about the system. For example, they might choose to investigate whether sites with higher flow velocities correlate with higher sediment sizes.

This activity reinforces specific concepts about streamflow and sediment transport, and also illustrates how the field of geology contributes to our understanding of the interaction of humans and their environment.

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