Essay On Edwards-Trinity Aquifer

In 1935 the Hoover Dam was completed forming Lake Mead, providing flood control, reservoir storage, power generation and regulates the downstream flow to the Lower Basin States. [footnoteRef:20] In 1963, the Glen Canyon Dam was completed forming Lake Powell, providing the Upper Basin States with enough reserve capacity to allow them to meet their annual obligation of 7.5 Million Acre Feet (MAF) to the Lower Basin States, allowing the Lower Basin States to use the allocation.[footnoteRef:21] As a consequence of the construction of the Hoover Dam and the Glen Canyon Dam, the Colorado?s flow often evaporated in Mexican sands close to the Delta.[footnoteRef:22] Around the 1970s, the Cienega de Santa Clara had shrunken by 500 acres. Nevertheless, due to the following wet decades, the Cienega was resuscitated to about 10% of its original acreage in the 80?s and 90?s.[footnoteRef:23] Currently, the Cienega is a 40,000 acre wetland that exists due to the return flows from the Mohawk Irrigation and Drainage District near Yuma, Arizona.[footnoteRef:24] This Cienega is the home of less than 100 members of the Cucapa tribe and is the habitat of several endangered fish and birds, including Desert Pupfish and Yuma Clapper Rail.[footnoteRef:25] [19: D.F.

Webb (2003) conducted numerical analysis of source-water dynamics of stream-bounded alluvial aquifers, along the Ohio River in northern panhandle of West Virginia, with consideration of lateral infiltration of groundwater from bedrock aquifer. However, the author did not verify her model to the field data. On the other hand, Kozar and McCoy (2004) presented groundwater-surface water interaction and simulation of groundwater flow in the alluvial aquifers from the northern panhandle of West Virginia without considering recharge form adjacent bedrock and leakage from overlying tributary streams. Although, Bader et al., (1997) and Unthank (1999) independently identified that the alluvium along the Ohio River, West Virginia and Kentucky respectively is recharged by the following means: (1) precipitation on the flood plain, (2) inflow from fractures in the bedrock beneath and adjacent to the alluvium, (3) inflow from tributary streams through gravel deltas and bedding-plane partings, and (4) induced inflow from the river. Water flowing in tributary streams can percolate through the deltas to the gravel under the clay-silt layer (Grain, 1966). Unthank (2013) updated model and reran it which generated significant difference between measured water levels and model-computed water levels in the aquifer. The author concluded that more accurate and site-specific estimates of field parameters, refined model geometry, and additional numerical method improve

The Atchafalaya Basin is the nation's largest river swamp, containing almost one million acres of America's most significant bottomland hardwoods, swamps, bayous, and backwater lakes.

Cenozoic sedimentary rocks predominated to the west and east of the central mountain while plutonic rocks predominated in the peninsular ranges. The irregular contact between these geologic regions reflects the ancient topography of the area. The ancient oceanic crustal plate created an archipelago of a volcanic island. The former's subduction created immense volumes of magma. This resulted to the congealation of plutonic rock in the crust. The local rocks that existed before the tectonic forces uplifted, and erosion capped the deeply buried plutonic rocks that formed a steep and rugged mountains coastline, similar to that present one, which in the west coast of south America.

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.

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.

Little Cottonwood Canyon is a site bursting with geological history, rock formations earthquake potential on the fault, prehistoric glacial formations, landslides, and many hazards associated with it. The Wasatch fault is bound to have a enormous earthquake in the future and has left behind numerous scars. The mountains have been engraved by glacial formations dated back to the Ice Age (~14,000 years ago). Rock falls and landslides have left hefty boulders as indication of erosion and moisture in the rocks. The hazards on this mountain range are mass wasting, radon, earthquakes, and flooding of Little Cottonwood Creek.

First, we must examine the sedimentary formations; when they were formed, how they were formed, and what materials they consist of. About ninety-three to one hundred million years ago, the Western Interior Seaway rolled through the North American continent, eventually reaching the geographical area of today’s Mesa Verde National Park (National Park Service 2005). This sea deposited a thick, hard sandstone base that is called Dakota Sandstone, although this layer is not exposed in the park

Extending from sea level at the Gulf of Mexico to over 8,000 feet in the Guadalupe Mountains of far West Texas and from the semitropical Lower Rio Grande Valley to the High Plains of the Panhandle, Texas has a natural environment best described as "varied." Below is a summary of the size, the boundaries, the highs and the lows of the state.

The state of Texas is the second largest state in the United States. Due to its location and size, it covers different geographical areas and climates. These areas support different ecosystems from deserts to coastal wetlands, with local wildlife varying with the environment. With such varied climates and yearly rainfall, it is easy to have crops growing in the east and little rainfall and an open rocky desert with cacti in the west. The geological history is also varied across the state leading to different mineral deposits by region. It is easy to see that Texas is a state with many unique areas that provide a wide variety of natural resources, native crops, and wildlife.

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

To begin, Withlacoochee River Park is both ecologically and hydrologically important, for not only does it supply most of central Florida with its drinking water, but also encompasses parts of the Hillsborough, Withlacoochee, Ocklawaha, and Peace rivers. The aquifer itself is unique, as it is at a higher elevation than

The Edwards Plateau is a plethora of various plant and animal species as well as picturesque landscapes making it a prime source of natural studies. But one thing in particular sticks out: the Edward Aquifer. It is the sole source of drinking water for the over million population of the city of San

This formation is a very fine grain Mississippian limestone. To test to see if this was the Bangor formation we used HCL and because there was a reaction we know its limestone. This formation could also be described as gray in color as well as an average thickness of 700 feet. We see the Bangor until stop eight, where we see a very different vertical bedding. Also different at stop eight is the outcrop no longer reacts with HCL. From this we gathered that we had moved into the Hartselle formation. In the Hartselle Formation, Mississippian aged sandstones are dominant. This particular stop had a large amount of jointing. After the Hartselle, we figured the Pride Mountain Formation would be next, however at stop nine we see the Maury Formation present. This stop focused on the rock located inside the creek. Because we were unable to go into the creek to get the strike and dips, we once again had to do a projected orientation. Also found on this stop were natural sulfur springs, easy to notice with the smell that it gives off. The Maury formation consist of Mississippian- Silurian aged shale. At the next stop, stop 10, we encounter the Ft. Payne formation. Although this area location was thickly vegetated, we were able to conduct the acid test and saw that the HCL reacts in some places but not all. From this we concluded that this was the cherty limestone of the Ft. Payne formation. The following stop, 12, we went up section and arrived at the Maury Formation once again. At the final stop, location 13, we see Ft. Payne Formation. All of the metamorphism and deformation in the southernmost Appalachians can be related to the movement of the thrust sheets and stacks (Higgins,