Apologia General Science, Module 6, Foundations of Geology

►What we did at Sahm-I-Am

Students:
• Quizlet M6
• Online practice quiz
• How are materials from the earth broken down?
-Click on a scene at the top.
-Click on Hear below the larger image.
-Click on the water or oxidation symbols at the bottom to see how these cause erosion.
• How do glaciers shape the land?
-Click on one of the two tabs at the top, then click on the labels to learn about the landforms.
-At the bottom, look at the Site that is shown, and figure out which landform it is.
-Use the Clue if you need it.  Check your answer.
-Scroll down and choose another Site.

Parents/Educators:
• Petrified paper
• Weathering and Erosion - lots of links!  I love the 12 stations; we're doing some of those.
• Stations worksheets - I typed up my own using these for an example.
• Teacher-Friendly Guide to Geology.  Nice guides for educators based on your area of the country.  See the left sidebar.
• Some good pages found here under "Geology"
See these and more at Debbie's Educator's Resources.  (Thanks, Debbie!)



(1)  p. 137-138 Introduction
Uniformitarianism and Catastrophism



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(2)  p. 138b-142a, Soil, Rocks, and Minerals
The top layer of soil is rich in humus.  Humus is the decayed remains of once-living creatures, and contains nutrients that plants use.
Other components of most soil are gravel, sand, silt, and clay.

This tells how to determine if soil is good for growing things - if the soil is a "loam," which you don't need to know yet, but still a good video about the different components of soil.



Way beneath the dirt of the earth's crust is a solid layer of rock.
There are three main kinds of rocks:  sedimentary rock, igneous rock, and metamorphic rock.

• Igneous rock is formed from magma (molten rock deep in the earth).  Sometimes the magma cools inside the earth, and other times it erupts from volcanoes.  
• Sedimentary rock is formed from particles of shells, or sand and pebbles weathered from igneous rock.  Together, these particles are called sediment.  When the sediment accumulates in layers over time, they harden into sedimentary rock. You can see the sediments in the rock. 
• Metamorphic rock is formed from igneous rock and/or sedimentary rock under the surface of the earth due to high heat and pressure, but not hot enough to melt.  If metamorphic rock gets hot enough to melt, it becomes igneous rock.  

These rocks form from one another in the rock cycle.

From ingeous rock, to sedimentary rock, to metamorphic rock.



There are different types of igneous, sedimentary, and metamorphic rocks.
The Rock Song!  ♪♫  ☺
(Remember to be gneiss, lol!)



►What kinds of rocks are found where you live?

Minerals are inorganic.  This means they didn't come from a once-living being.  Minerals are crystalline substances found naturally in the earth.
A crystalline substance has a sharp, geometric shape.  It doesn't have rounded edges like most rocks you see.  These sharp-edged minerals are what make up rocks.



Great video showing many types of minerals.  I love the "peacock ore" at 5:30 -- So pretty!!!
Some have been through a rock tumbler and are now smooth.



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(3) p. 142-145, Strata in Sedimentary Rock


Arial view of the Grand Canyon. Beautiful!!!



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(4) p. 145b-149, Weathering of Rocks
Weathering is the breakdown of rocks, soils, and minerals into sediment by the forces of nature.
►Look at these awesome pictures of weathering.

There are two types of weathering:

• chemical weathering from acid rain or rust
• physical weathering from wind or water carrying sediment that wears away at rocks and shorelines, or from extreme heat or cold, or from plant roots that break up sidewalks or pavement, etc.

However, both types of weathering occur in place.
►Once the sediment moves away from its location, then it is called erosion.
(Please ignore the reference to billions of years.  sigh.)
This video is actually about both weathering and erosion.

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(5) 149b-154a, Erosion
Erosion is displacement of rock fragments, sediments, soil, and other particles that are carried away by wind, rain, or ice.



Rivers carry along sediment and deposit it into a larger body of water such as a lake or more commonly, the ocean.
River erosion.



"A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river. Over long periods of time, this deposition builds the characteristic geographic pattern of a river delta."
-Wikepedia



A delta gradually grows further out into the ocean (or lake, etc.) while at the same time builds up so that part of it is above water.  Plant life can grow here.  The main river will cut through this body in several branches and continues to the ocean.  On this picture of the Nile Delta, you can see the delta extended into points at those areas.



Caverns are another kind of erosion.  It is common for the different "rooms" in caverns to be named for their appearance.

Yay for bats!  =)




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(6)  p. 154-156, Bringing it all Together:  The Basic Structure of the Grand Canyon



►More about the Grand Canyon at Answers in Genesis.


An unconformity is a surface of erosion that separates one rock layer from another.  In other words, the layers are not totally level because one has eroded a little before more sediment was laid down.  It did not conform to regular layering.

Various unconformities in order of the video:

1. A disconformity occurs where there are parallel, stratified rock layers above and below a disconformity, but there is erosion between them.
2. An angular conformity is at an angle, with more layers on top if it.  The Great Unconformity is an angular connformity in the Grand Canyon.
3. A nonconformity  is when stratified layers rest on top of unstratified layers, such as the separation of metamorphic or igneous rock and the first layer of sedimentary rock on top of it. (Nonconformity isn't labeled in your book, but it is there at the bottom of the picture.)
4. Paraconformities will be discussed in Module 8.

An intrusion forms when magma from under the sedimentary rock is injected into the cracks of the sedimentary rock.  It hardens into a "vein" of igneous rock.
Intrusions that run parallel to the sedimentary layers are called sills (horizontal like a window sill).
Intrusions that run perpendicular to the sedimentary layers are called dikes.  Perpendicular lines form a kind of T to each other.

The lower layers were indeed laid down before upper ones, but that does not mean it took millions or billions of years.  It shows the relative age - how they are related shows that one is older than another, but not by how much.
Remember, there is nothing between the layers to indicate great amounts of time had passed.  No plants that grew, not enough weathering, etc.


1:50 - nonconformity on top of intrusive igneous rock.
3:05 - disconformity
3:48 - angular conformity
4:25 - intrusion