rocks_lab1

GEOL 121 4. Your instructor will give you a new set of samples (Sample Group B). Consider how effective each of the classification schemes your group and your neighbor group \ came up with were in classifying these samples. Then, develop and describe a revised classification scheme based on your discussion and the introduction of the new data (samples). Our classifications are still effective and so were our neighbors’ group. A revised classification scheme we could use could be grain size, layers of grain, and density of the rock. 5. Instead of rocks, imagine that your instructor had asked you to classify fruit- apples, pears, cherries, blueberries, oranges, limes, blackberries, bananas, in order to determine how they are related to each other. a. Would classifying the fruit by color or size help scientists identify and distinguish between different fruit groups? What issues could arise if these characteristics alone were used? E.g., how would this impact the classification of new fruits (pineapple, melons, tomatoes, avocados, etc….) No because if you were to have two apples, one green and one red, they are both apples, but they appear different and can have different tastes. b. Identify classification schemes that could help you divide these fruits into groups that illustrate how they are related to each other. Are there any observable characteristics could you use? Shape/size of the fruit could be an observable characteristic that we could use to classify the fruits. *wait for instructor guidance before beginning Part 2 Part 2: Scientific Classification of Rocks 3

GEOL 121 combination of high heat, high pressure, and hot mineral-rich fluids. 2. Fill out the first three columns of the chart below, classifying each sample from Sample Group A according to the sub-type described on the previous page. Include a description of your reasoning; what observations support your hypothesis? Rock Sample # Hypothesized Classification & Formation Mechanism Supporting Observations & Reasoning Corrected Classification & Formation Mechanism Supporting Observations & Reasoning 1 Igneous intrusive Can see crystals with naked eye 2 Sedimentary chemical Minerals cemented together Sedimentary detrital Cant see the crystals 3 Igneous extrusive Light in weight, no large crystals 4 Metamorphic foliated Banded, visible interlocking crystals 5 Metamorphic nonfoliated Has crystals but no foliation 6 Sedimentary detrital Large particles cemented together 7 Igneous extrusive Small interlocking mineral crystals Igneous intrusive Large interlocking minerals 8 Sedimentary chemical Effervesces 9 Metamorphic foliated Banded but non visible crystals 10 Sedimentary detrital Large crystals cemented together Igneous extrusive Visible crystals, growing in fine grain 11 Igneous intrusive Visible crystals of different types 12 Sedimentary detrital Feels like sandpaper 6

GEOL 121 3. What aspects of making observations, rock classification, and/or the six rock categories defined in this lab do you feel most confident about? I feel most confident about the more straightforward aspects of identifying rocks such as looking for banding, different layers, and if you can see crystals interlocking together or not. The system of classification developed by our group in Part 1 was relatively easy to use because it relied on readily observable characteristics like color, texture, and crystal presence 4. What aspects of making observations, rock classification, and/or the six rock categories defined in this lab do you still have questions about? How one would be able to do this in the field if you don’t have a magnifying glass or something of that sort. 9