* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Name: _________________________ REGENTS EARTH SCIENCE Glacial Sediments Lab Date: _______________ Per: ______ Lab # _________ Analysis of Glacial Sediments Glaciers deposit material in two different forms – as till and as outwash. Till consists of material that was carried by the glacier and deposited directly by the glacier as the ice melted. A till deposit contains particles of all sizes in an unsorted and unlayered mass. Outwash is material that is eroded and deposited by streams flowing away from the melted ice - it is sorted by size and often layered. The running water sorts the materials as it deposits so that, in an outwash sample from any given area, one particle size is much more common than any of the other sizes. Goals of this Activity: To identify a sample of glacial sediment based the characteristics of its sediment sizes it contains. The sample you will analyze was collected from an area that has been affected by glaciers moving over the area. Essential Question – Is the sample of sediments we have glacial till or glacial outwash? Materials: safety goggles unknown glacial sediment (either till or outwash) sieve set consisting of four screen sizes (#6, #20, #40, and #100 or similar), pan, and lid electronic balance 250 mL glass beaker to contain sample 100 mL plastic beaker to use as a pedestal for massing the screens Procedure: 1. Put on your safety goggles. 2. Determine the mass of the empty glass beaker and record the value in Table 1. 3. Disassemble the screen sieve set and ensure that there are no sediments stuck in the screens. Place the plastic beaker on the balance and tare it to zero it out. Balance the parts on the beaker and determine the mass of each empty screen and the pan. Record each of these masses in Table 1. 4. Use the glass beaker to obtain a sample of the glacial sediment. Limit your sample to about half of the beaker’s volume. 5. Determine the total mass of the beaker with glacial sediment and record this mass in Table 1. To find the mass of the sediment alone, subtract the mass of the empty beaker from the mass of the beaker plus the sediment. Record this value in Table 1. Note that this mass is the total mass of the original sediment sample, so the percent of this total is equivalent to 100% of the sediment analyzed. 6. Stack the sieves and the pan in the correct order of their screen sizes, so that the smallest mesh in on the bottom (above the pan) and largest is on the top. 7. Pour all of the glacial sediment from the beaker onto the top screen. Place the sieve cover on the top. Shake the set of sieves horizontally for about a minute to sift the sample through the screens. 8. When the shaking is completed, remove the cover and carefully separate each screen from the one below it. This may require teamwork – one person holds it down while the other lifts… 9. Determine the mass of each screen/pan together with the sediment it contains. Record each value in Table 1. 10. Subtract the mass of each empty sieve/pan from the mass of the screen/pan with the sediment determined in procedure step 9. The total mass of sediment from all of the sieves and the pan should equal the total mass of the original sediment sample obtained in procedure step 5. If the difference in the two values is more than 3 grams, discard all parts of this sample and return to the procedure step 4 and repeat to obtain new data. 11. To find the percent of the total mass, divide the mass of the sediment alone retained in each screen or pan by the total mass of the original sediment sample. Multiply each of these answers by 100 to change to a percentage. Record this information in Table 1. 12. Plot the percentage values as a bar graph on Figure 1 to show the relative percentages retained on each screen. 13. Find out from your teacher the screen size of each sieve. Record each of the screen sizes on the lines provided in Table 2. Table 1 – Mass Analysis * Object Mass of Empty Container (0.1 g) Mass of Container plus Sediment (0.1 g) Mass of Sediment (0.1 g) Percent of Total Mass of Sediment (0.1%) Grand Total Sieve Sediment Masses Grand Total Sieve Sediment Percentages Beaker Top, or largest, screen Second screen from top Third screen from top Bottom, or smallest, screen Pan * Record all values to the nearest tenth of a unit. Table 2 – Mesh Sizes Top screen = ___________________ mm Second screen = ___________________ mm Third screen = ___________________ mm Bottom screen = ___________________ mm Pan Figure 1 Analysis and Conclusions: 1. Which screen retained the largest percentage of sediments? ______________________________________________________________________________ 2. Did each screen contain a portion of the sample? ___________ What does this tell you about the sample? _________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ The grid below shows sizes (in millimeters) and names of the major sedimentary particles. Locate each of the screen sizes on the grid below. At the correct location of each size, draw a vertical line through the strip below the sediment size names. Write the name of each layer (from the diagram on P. 1) in the area between the vertical lines you just drew. For example, since the top screen size is 0.5mm, the vertical line separating medium sand from coarse sand should extend down across the strip and “top screen” is written in the space to the right of the line you just drew. 0.01 0.0625 Fine Silt Medium Silt Coarse Silt 0.125 Very Fine Sand 0.25 Fine Sand Medium Sand 0.5 1.0 Coarse Sand 2.0 Very Coarse Sand 4.0 Granules 8.0 Small Pebbles 3. On which screen were particles 0.6 mm in diameter retained? ______________________________________________________________________________ 4. On which screen was very coarse sand retained? ______________________________________________________________________________ 5a. List the particles sizes that were retained on the bottom screen by name: ______________________________________________________________________________ 5b. Now list them by their size range: ______________________ 6. On which layer did the silt-size particles end up on? ______________________________________________________________________________ 7. Only rarely does the total mass on the screens exactly equal the total mass of the original sample. Did your total mass increase or decrease? What is a possible explanation of why it increased/decreased? ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ CER Question: Are the glacial sediments you analyzed a sample of outwash or till? Draft your answer using the CER graphic organizer on the following page. Then, use this graphic organizer to type up your final response in a clear, well-written CER. Your goal is to stay in the far right-hand column of the rubric provided!!! Reminders: Reread the introduction and the directions carefully before you construct your write-up. All questions require complete sentences; remember to incorporate quantitative and qualitative data in the response. Double space your writing! Staple your completed, printed CER to the back of this lab. Claim, Evidence and Reasoning Writing Organizer Claim What is the claim you can make based on your evidence? (The answer to the question being asked that you believe is the correct answer based on what you’ve learned from the evidence that you will present!) This should NOT start with “Yes” or “No”!! Evidence: What is the evidence you collected? (Specific Data – Qualitative and Quantitative – list and compare/contrast the data. Use your ELA transition words in your writing!) Reasoning: Explain why you can make the claim from the evidence you collected. (This is the explanation. Incorporate/restate the claim, and state the scientific principle(s) that connects your claim to your evidence!) Rubric for Glacial Sediments Analysis Claim, Evidence and Reasoning (CER) Directions: Use this rubric to ensure that your CER is well-written! Getting Started Keep Trying Getting There Nicely Done! 0 1 2 Typed but multiple Write-up Not typed spelling/grammatical errors are present. 0 Claim Claim is incorrect 0 1 Typed and proper grammar and spelling are present. Few, if any, errors present. 1 2 Claim is correct but Claim is correct and is not well-written and well-written in a clear not expressed well. manner. 3 5 Provides appropriate Doesn’t provide any quantitative Evidence Does not provide any evidence. evidence to support claim. Poorly written/didn’t apply ELA skills. but not sufficient Provides appropriate evidence to support and sufficient claim. Incomplete evidence to support evidence. Does not claim. Both include both quantitative and quantitative and qualitative evidence is qualitative evidence. provided. Well-written Writing needs and organized. improvement. Provides some reasoning that Reasoning Reasoning Does not provide any reasoning. provided is not appropriate and does not explain the evidence. connects the evidence to the claim, May include some scientific principles for why the evidence supports the claim, but not sufficient. Not wellwritten/organized. Provides clear, wellwritten reasoning that connects all evidence to the claim. Includes appropriate and sufficient scientific principles to explain why the evidence supports the claim.