Periods or Epochs Of The Geologic Time Scale
GEO -Discussion – Week 6
Choose one of the periods or epochs of the geologic time scale and describe it. Be sure to include its numeric age, any major fossil groups that lived then and any major geological events that took place at that time. Feel free to include anything else that you might discover such as climate, oxygen levels or extinctions.
Alternatively, you can choose a landform near to you, one that you’ve visited or one that you find interesting. Describe that landform including its location, type, elevation and the age of the rock. Compare the age of the landform to the ages of the rocks adjacent to or surrounding it.
Now, take a look at two other classmates’ responses and identify where you agree or disagree with their conclusions.
GEO – Assignment – Week 6
Using the geologic map of Virginia, answer the following questions: GEO101_Lab6_Module6_Map.pdf
Is the region in the extreme northwest corner to the Potomac River strongly folded or strongly faulted?
Is the region from the southeast corner to Harrison Island along the Potomac strongly folded or strongly faulted?
In the southwestern part of the map, along the Shenandoah River, the sediments are only Quaternary in age, yet they are surrounded by much older Cambrian sediments. How do you explain this?
In the southeastern corner of the map, locate Rockville and Gaithersburg. Notice that they are separated by the Plummer’s Island Fault. Is Rockville moving atop Gaithersburg or is Gaithersburg moving atop Rockville?
Find Martinsburg, WV, in the extreme northwest corner. Now locate Martinsburg, MD, which is just to the to the east of Harrison Island and Mason Island along a bend in the Potomac in the south central area of the map. Which is surrounded by the older rock?
Locate Long Marsh Run just south of the West Virginia/ Virginia border on the southwestern side of the map. Which way is it flowing?
How many different ages of rock would you encounter along its course?
In the middle image at the bottom, to the far right, you see that the younger Prettyboy Schist lies beneath the older Mather Gorge Formation. How can older rock be found atop younger rock?
Locate the oval, brown rocks near the center of the map. What geologic feature is this?