Week 8: Geology that kids see

1.      What did you do in lab today?

In lab we explored fossils that are found in Iowa. We sorted the fossils and looked at them under a microscope. We found lots of brachiopods and corals. Both were animals that would stick to the sea floor. Next, we looked at 11 different types of sand under a microscope. We wrote down observations and characteristics of each type. It was surprising to see how many differences there were because before looking at them under a microscope they all looked very similar. We finished lab by visiting the museum of Natural History in MacBride Hall and looking at the animals that were previously found in Iowa.

Sand 1: not as much variety in the size, opaque colors, white, beige, brown

Sand 2: orange color, some brown colored rocks some opaque rocks various sizes

Sand 3: darker color, black, crystals, larger size  

Sand 4: clear/white smaller size ricks, not as much variety in size

Sand 5: multicolored rocks, red, orange, clear, black

Sand 6: all the same color, yellow/white/clear

Sand 7: multicolored rocks, darker colors, various sizes

Sand 8: red/orange, various sizes, some white/clear

Sand 9: white, black, grey, finer/smaller rocks

Sand 10: largest rocks, light colors, pink, yellow, white, clear, most variation in size

Sand 11: little pebbles, white color, looks like little egg-shaped rocks

2. What was the big question?

The big question we discussed was: What do historical artifacts and fossils tell us about the location where they were found?

2.      What did you do in Thursdays discussion?

These are my notes from Thursdays discussion:

The Devonian Period in Iowa

·       Iowa was once a warm, shallow in-land sea

o   It was not an ocean – this is a common misconception

·       We were south of the equator- that’s why it was warm

·       Organisms contributed to the formation of extensive reef systems particularly in Eastern Iowa

·       Post this time period was when we started to get land plants and animals

Characteristics of sand

·       Sand created through water is polished, smooth, and generally similar in size

·       Sand created through glaciers is polished, smooth, but irregular in size

·       Sand created through wind is opaque, frosted, pitted, and very fine grained

Rock cycle

·       All started from magma

·       Igneous

·       Metaphoric

·       Sedimentary

Extrusive- when magma cools fast and exits the crust of earth, cools fast

Intrusive- magma inside earth, insulated by earth, large crystals

Chemical factors- change the rock

Mechanical factors- does NOT change the rock

Erosion (moving the rock)-water, wind, or glaciers 

Weathering- breaking things down

·       Law of Superposition

o   the oldest rocks are at the bottom of the rock

o   rocks form in layers that become buried under more layers over time

o   helps know the relative ages of the rocks

 

4. Read the online textbook chapter 2. 

• What did you learn?

One thing I learned from the textbook chapter was how the characteristics of sand and fossils can give us information about where they were found. For example, sand that is smooth and shiny was likely formed by water passing over the rocks. Sand that has more texture and is dull was likely formed in a windy area where things have hit and blown into it. Weathering by wind and weathering by water are the two main types that we characterize sand by. Fossils are similar and can tell us where they were found in the world. If sand is black, it was likely made from lava that has cooled, so it is found near volcanoes.

·       What was most helpful?

Something that was especially helpful to me was learning about the difference between the two types of erosion, chemical and mechanical. I did not know there was a specific difference between how erosion happens. Chemical erosion is when rocks change due to chemical reactions that happen to the rock. Mechanical erosion is when a physical property such as wind, weather, or water cause the rock to change.

·       What do you need more information on?

Something I need more information on is how scientists are able to get images of all the layers of rock to study the law of superposition. I’d like to learn more about the tools or methods they use to collect samples from the deepest layers, since they are so far underground. I’m really curious to understand how this process works.

5. What questions, concerns, and/or comments do you have?

I do not have any further questions or comments.