GEOLOGY 1-C01FIELD/LAB ASSIGNMENT PART II Jaime Cardenas
Fault I visited the world renown San Andreas Fault. According to Earth by Tarbuck and Lutgens, the San Andreas Fault is a transform fault, which means the plates side past one another without producing or destroying lithosphere. I visited Mission San Juan Bautista, which was famously built on a ridge top. This ridge top is actually a fault scarp which marks the San Andreas Fault’s trace. This section of the fault is knows as the creeping section. According to About.com, the creeping section moves about 3 centimeters per years and only experiences minor quakes. The first image was taken at the foot of the scarp. The second image is a plaque that commemorates the 100th anniversary of the US Geological Survey. The third image looks downward toward the bottom of the scarp.
Mechanical Weathering According to Tarbuck and Lutgens, mechanical weathering occurs when rock breaks down into smaller pieces, but still retains it’s mineral composition. I believe these images to be examples of mechanical weathering. In the first image, it appears that the smaller piece of rock was once a part of the larger rock. I believe the second picture also illustrates the same concept. Lastly, I believe the third picture may illustrate block weathering. Looking closely, one can see clear-cut lines of fractures of rocks laid atop one another. All three pictures were taken along the coast of the Mexican state of Jalisco.
Chemical Weathering According to Tarbuck and Lutgens, Chemical Weathering occurs when rock is chemically transformed into one or more new compounds. In the first image, the rocks appear to be enduring oxidation. According to Tarbuck and Lutgens, oxidation, “occurs when electrons are lost from one element during the reaction.” It was taken along the coast of Emeryville, CA. The second image also shows oxidation in a diesel storage tank located on a pistachio ranch near Kerman, CA. The third imaged, located on the next page, is that of a statue carved out of stone that appears to have endured chemical weathering. It was placed on it’s own slide to help display the detail on the statue’s surface. It was taken outside of a church in Jalisco, Mexico.
This image displays astatue carved out ofstone. It was taken ata church in Jalisco,Mexico. The stoneappears to have gonethrough chemicalweathering.
Erosion Tarbuck and Lutgens state that erosion is the physical removal of materials via mobile agents such as wind, water, or ice. The image below shows cliff erosion, as soil and rock are moved downward by rains and wind. It was taken near the coastal area of Jalisco, Mexico.
Mass Wasting According to Tarbuck and Lutgens, mass wasting is the down slope movement of rock, regolith, and soil due to gravitational forces. The first image was taken at the foot of a cliff in Jalisco, Mexico. As we can see, loose rocks collect at the base. These rocks were pulled down slope due to gravity. The second picture also shows mass gravity as smaller rocks tumble down slope due to gravity.
Continental Environment Tarbuck and Lutgens state that a continental environment is dominated by the erosion and deposition associated with streams. The image below was take at Pine Flat. Pine Flat is located in the foothills of Fresno County leading up to Yosemite.
Marine Environment According to Tarbuck and Lutgens marine environment is divided according to depth. The following picture was taking while whale watching in the Monterey Bay, CA.
Transitional Environment Tarbuck and Lutgens state that a transitional environment is the transition zone between continental and marine environments. This picture was taken at the beach in Malibu, CA.
Practical Use of Geology The world renown Golden Gate Bridge is admired around the world for it’s aesthetic beauty and engineering genius. It is widely used to cross from one peninsula to another. Thus, it is a great example of a practical use of geology. This picture was taken in San Francisco, CA.
References Tarbuck, E. J., & Lutgens, F. K. 2008. Earth: An introduction to physical geology. Upper Saddle River, NJ. Pearson Prentice Hall. About: Geology. www.geology.about.com. Retrieved on November 9, 2011.