Sediment is looked at in a couple of different ways.
The layering has occurred by processes of either weathering or erosion. You can see by watching the news like in the winter of 2016/2017, during the heavy rains tons of material came down out of the hills and flooded the area’s below. Sometimes this filled up old lake bottoms, sometimes in the flatter area’s and the level rose feet above what was previously there. The years before this almost no rain came down and the flooding was at a minimum and you didn’t notice any run off or new material being bulldozed up and trucked away.
Some of the others ways are the bottom of a lake that has consent flow from a river that is carrying material down into it, it dries up over the years, faults move the ground up to help form mountains, we cut into these mountains for building roads and expose these ancient layers.
Now, looking at these old layers before you, you can see thicker layers. Some of the layers are thin, some medium, some have rocks within them, some have boulders. These layers can be classified by the grain size which will also help figure out the flow of these when they formed.
Now another way to look at these layers are to see the material color and research to see what colors mostly make up what material. Properties of what the material is made from help cause the color. Sometimes like Red is from the Iron content, sometimes like in Amethyst a purple color is also determined by the amount of Iron present. Manganese and cobalt with be responsible for Pinks, Chromium for deep green. Minerals composed mostly of the elements of aluminum, sodium or potassium is normally colorless or very lightly colored.
Minerals are divided into two classes, based on what causes their color:
Idiochromatic:
These are minerals whose color is determined by a coloring agent that is a regular part of the ideal chemical formula.
Examples are:
1. Gold is yellow because the element Au absorbs all other colors except yellow.
2. Azurite is blue because the copper in azurite molecules absorbs all other colors except blue.
3. Crocoite is red-orange because the chromium in crocoite molecules absorbs all other colors.
Allochromatic:
These are minerals whose coloring agent is not part of the ideal chemical composition. There are 4 mostly agreed upon cause of color in allochromatic minerals they are: a. Impurities, b. Inclusions, c. Charge transfer, and d. Color centers.
Examples:
1.Amethyst: Add some iron to clear, pure quartz and it becomes purple
2.Citrine: Inclusions of Fe+++ cause the yellow color in citrine.
3.Rose Quartz: Trace amounts of titanium or manganese turn quartz pink.
Logging Requirements: Please E-Mail me the answers, don't post any pictures of the site itself.
1. Type in "GC7DYD1 Sediment Layering, it's Color and Grain size"and how many with you today?
2. What do you think is the main grain size off the chart?
3. What is the main material that makes up the color of this example?
4. How were the thicker layers formed do you think?
5. Are there any stones or rocks left in any layers? what size?
6. Is this example Idiochromatic or Allochromatic?
The following Material were used for Reference:
- Cal tech Geology research
- U.S. Department of the Interior, Professional papers and Geological surveys
- Wikipedia
- California Institute of Technology
- https://people.uwec.edu/jolhm/interstate2006/potholes.htm