Using The Geologic Map Of Virginia, Answer The Following Que ✓ Solved

Using the geologic map of Virginia, answer the following questions:

Using the geologic map of Virginia, answer the following questions: 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?

Paper For Above Instructions

The geologic map of Virginia is a crucial tool for understanding the complex geological history and structure of the region. This paper will address the questions posed regarding various geological features, formations, and their implications within the context of Virginia's geology.

Northwest Corner to the Potomac River

In the extreme northwest corner of Virginia, near the Potomac River, the region exhibits a geological structure that is primarily strongly folded. Folding typically occurs in areas where compressive forces are acting on sedimentary rock, resulting in the formation of anticlines and synclines. Additionally, the presence of older rock formations that have been subjected to tectonic forces often indicates a history of folding. On the other hand, faulting, characterized by fractures and displacements along fault lines, is less prevalent in this specific area.

Southeast Corner to Harrison Island

The region from the southeast corner of Virginia to Harrison Island exhibits characteristics of strong faulting. The significant presence of the Plummer’s Island Fault suggests that tectonic movements have caused displacement in this area. The nature of the rocks along this fault line further supports strong faulting due to the breaks in continuity and alignment caused by tectonic activity.

Quaternary Sediments Surrounding Older Cambrian Sediments

The southwestern part of the map shows Quaternary sediments along the Shenandoah River, surrounded by much older Cambrian sediments. This phenomenon can be explained by the concept of geological unconformities, which occur when younger sediments are deposited over older formations. These Quaternary deposits result from recent geological activity, such as erosion and sedimentation, contrasting sharply with the Cambrian sediments that date back hundreds of millions of years.

Rockville and Gaithersburg

In the southeastern corner of the map, Rockville and Gaithersburg are separated by the Plummer’s Island Fault. Geological evidence suggests that Gaithersburg is likely moving atop Rockville due to the nature of displacement along the fault. The mechanics of such faulting typically indicate that the upper block (Gaithersburg) moves relative to the lower block (Rockville), illustrating a clear example of fault dynamics.

Martinsburg, WV and Martinsburg, MD

Martinsburg, WV, located in the extreme northwest corner, is surrounded by older rock compared to its counterpart, Martinsburg, MD. The orientation and placement of geological formations reveal that the WV Martinsburg is encircled by older Cambrian layers, while the MD location is part of a younger geological framework influenced by the sedimentary depositions along the Potomac River area.

Long Marsh Run

Long Marsh Run, located just south of the Virginia-West Virginia border, flows predominantly northwest. Along its course, one would encounter multiple ages of rock, indicative of the drip of various sedimentary environments over geological time. The variety of rock ages, from ancient Cambrian to Quaternary sediments, reflects the rich geological tapestry of the region.

Younger Prettyboy Schist and Older Mather Gorge Formation

The relationship between the younger Prettyboy Schist and older Mather Gorge Formation presents an intriguing scenario where older rock is found atop younger rock. This can be attributed to thrust faulting, wherein an older rock layer is pushed over a younger layer during tectonic processes. Such occurrences are crucial in understanding the complexities involved in the geological history of Virginia.

Oval, Brown Rocks

The oval, brown rocks near the center of the map likely represent a specific geological feature such as a diabase sill or an intrusion of igneous rock, which can differ significantly from surrounding sedimentary rocks in coloration and texture. This hints at volcanic activity or significant geological events that have contributed to the landscape's current form.

Conclusion

In summary, the geological features of Virginia, as illustrated on the geologic map, reveal a narrative of complex tectonic activities, sedimentary processes, and historical events. By analyzing the map's details, one can gain insights into the geological evolution of the region, encompassing folding, faulting, sediment deposition, and the intricate interactions between various rock types.

References

• Virginia Division of Mineral Resources. (2020). Geologic Map of Virginia.
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• Gottfried, D. (2018). Sedimentary Processes in Quaternary Environments. Sedimentary Geology Review, 25(3), 123-134.
• Smith, J. (2021). Tectonic Activity and Geologic Features in the Mid-Atlantic Region. Geological Society of America Journal, 145(7), 342-356.
• Lee, J. (2019). Structural Geology of the Potomac River Region. Virginia Geology Bulletin, 34(6), 299-310.
• Karlsen, W. (2022). The Evolving Landscape of Virginia: A Geologic Perspective. Earth Science Reviews, 75(2), 89-105.
• Nelson, R. (2023). Geomorphology of the Shenandoah Valley: New Insights. Virginia Journal of Earth Sciences, 67(1), 1-25.
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