Quaternary Geological Map

10. This Figure 3 vertical cross-section exhibits a profile consistent with a tectonically [(passive)(active)] coastal region.

The west coast of North America has been tectonically and volcanically active for billions of years. The Sierra Nevada Mountains in eastern California were born of volcanoes, and magma has been erupting in the Long Valley to the east of the mountains for over three million years (Bailey, et. al., 1989). However, the climactic eruption of the region occurred relatively recently in the region's geologic history. About 760,000 years ago, a huge explosion of magma warped the Eastern Sierra into the landscape that exists today. The eruption depleted a massive magma chamber below the earth's surface so that the ceiling of the chamber imploded, forming what is now known as

California’s unique geography as a state makes it a very appealing place to call home. From the odd east to west transverse San Gabriel mountain ranges of the Los Angeles Basin, to the bumpy coastal ranges of the Bay Area, any person can find a compatible topographic terrain to their liking. California may seem to be the perfect place to live with its ideal climate and extensive geographic features. However, due to California’s location over the shifting continental plates, coupled with its enormous and also multiple faults, at any time this great state can fall victim to a seismic disaster. After examining evidence from both Rong-Gong Lin’s II Los Angeles Times article of April 18, 2016 and the NOVA videos Killer Quake ( 2006), Earthquake (2007), as well as Geologic Journey II – Episode 3 (The Pacific Rim: Americas) – Part 3 (San Francisco) and The Great San Francisco Earthquake (American Experience ~ 2005), one can take a comparative account of the three major earthquakes of California’s past. Although each earthquake was very devastating on is own; the Great Quake 0f 1906, the Loma Prieta quake of 1989, and the NorthRidge quake of 1994 each amounted to an extensive forfeiture of property and life. Each of these earthquakes created much suffering and loss. It is imperative for each citizen of this great state to understand the damage that a California quake can actually do and be prepared; for the threat of one always looms.

There are coarsening-upward sequences preserved, with flooding surfaces represented by low-relief erosional contact of trough-cross-stratification (runnel) upon low-angle planar bedding (swash zone).

The Central Valley of California, United States, is a notable structural depression which covers around 32,187km2 (Figure 1), and is bounded by the Cascade Range in the north, the Sierra Nevada in the east, the Tehachapi Mountains to the South, and the Coast Ranges and San Francisco Bay to the west (Planert 1995).

flood. However, Phillip Flat is located center of the other three lands and it makes

The formation of San Diego region involved numerous activities which varied from volcano activities, the formation of Gulf, uplifting and tilting among others. These activities happened in a long span of time creating three distinct geomorphic regions: the west of peninsular rangers, peninsular ranges region, and the Salton Trough region. The geomorphic division reflects the basic difference amid geographic parts containing Mesozoic metavolcanic, metasedimentary, and plutonic rock material. The development of these features resulted to the occurrence of the current San Diego state. The integration of different rocks, volcanic activities, and subduction processes resulted to the development of peninsular region and Salton Trough.

Questions and charts are from Geoscience Laboratory, 5th ed. (p. 155–167), by T. Freeman, 2009, New York, NY: John Wiley & Sons. Reprinted with permission.

* The Skillion, mainly the headland and rock platform, which is part of a preserved area of land known as “the Haven” which also contains the rugby oval. The man type of erosion that affects this is from the sea.

Questions and charts are from Geoscience Laboratory, 5th ed. (p. 117-130), by T. Freeman, 2009, New York, NY: John Wiley & Sons. Reprinted with permission.

One of the major things noticeable from the cross section is that quite a few of the rock layers are over turned, where the older rock layers are above the newer rock layers. This is seen in the contact between the Quartz Monzonite of Papoose Flat and the Campito Formation which is also a disconformity. Next there is some fault zones separating the Camptio, Poleta, and Harkless formations. We then see some more overturned layers with the contacts between Saline Spring Valley Formation (lower and upper members) above the Mule Spring Formation along with some inferred folding. With a normal fault separating the inferred folding event, we see where the overturning occurs. In between the Cambrian layers we see Tertiary Basalt nonconformities also being folded, thus with that we know that the folding event was more recent than the formation of the Basalt. Next there is a large Basalt field with a spot of the Harkless formation. Again we see over tuning as the Basalt field ends there are the Devonian and Mississippian rock Layers on top of the basalt. Separating these overturned layers from the Harkless Formation and the Saline valley Formation (upper member), which are not overturned, is a thrust fault. From this information, there was a major stress event sometime after the Tertiary period causing the rock layers to fold and overturn. And from this stress event and from the folding, normal and thrust faults are formed. Finally we see that there were alluvial and landslide deposits from the Quaternary after the folding, faulting, and over

Especially in the area around the Great Basin, since that covers most of the state. This area is surrounded by the mountain ranges and gets all the run off . This water helps with the water shortage throughout the year but at the time it is too much for the area to handle as there is no drainage to the ocean from this area. Groundwater is used throughout the state. Sometimes, the water is pumped out faster than it can be replenished. When this happens, the land surface can be affected. There are many cracks in the ground near Las Vegas, and in some places the land has sunken in over six feet within the last sixty years. An increase in the population of the state is to blame for the increased demand on the groundwater and therefore, the increased damage being done to the landscape as a whole. More people, more water, more land being developed, means less of the natural preservers being available. Also, with these floods the state sees landslides. The rocks of the area show the different ways the terrain was built

I have researched the effect of climate change on California’s natural water supply. California has a diverse climate throughout, being a large state with sixteen different climate zones recognized. These can be subdivided into four major climatic zones as follows: North Coast, South Coast, Central Valley, and Desert/Mountain.

They have sinuous, curving channels and their heights are higher compared to their widths (Thompson & Thompson, 2003). Irregularities toward the local direction of slant cause paths sinuosity. Canyons located in the Mammoth Cave run up to 80 to 100 feet high and 10-30 feet wide but many of them are not that high and much narrower. Vertical shafts are created where water can run down vertically alongside fractures (Call, 2010) as illustrated in figure 6.

Water from the south then flowed in over time, thus forming the evaporites now found along the coastlines there. (Lois Van Wagner, 2013)(Figure 5)