Introduction
The selected region for conducting the study for the final assignment is regarding Mount Diablo, which is located near the town of Danville, California. This essay includes a description regarding an assortment of geologic proceedings that have transpired in the region. Apart from this one of the geographical features are selected and explained.
General Scenario on Mount Diablo
“Mount Diablo occupies a unique geographical position”. (About mount Diablo, n.d., para.1). The position is situated on the margin of the Bay Area and the Central Valley This is “one of the largest view sheds” that is found in the Western parts of United States (About mount Diablo, n.d., para.1). This Mount is about 3,864 feet (1,178m). Approximately 20,000 acres (80km2) constitute the surrounding area of Mount Diablo. This is said to be foremost public open space and presently there are nearly twenty-nine preserves. Some of preserves include watersheds, regional parks, etc. There are also some private protected lands present in this region. The area gets more popular in winter as residents in this area will get a chance to experience the snowfall that falls on the mountain. In addition to this mountain offers an affluent multiplicity of “landscapes, views, hikes, and natural studies” (Baston, 1996, para.1).
An assortment of geologic proceedings that have occurred in the region
“People who don’t know much about geology often think that Mount Diablo must be a volcano given its shape and its name, but it is a complexly folded and uplifted body of mixed rocks whose history is not easily summarized and is still under study” (Mount Diablo, California, USA, 2008, para.1). However, Mt. Diablo is considered to be one of the best-known landmarks in California and its details of origin always been a great mystery. In order to understand about the geologic events occurred in this region it is necessary to look far beyond on the mountain.
Nearly two hundred million years ego it is believed that the floor of the ocean began to “slide like a giant conveyor belt beneath the western edge” (Werminskin, 1993, para.3) of the continent. This process is called subduction and “material “riding” on the oceanic plate was scraped off on the continental edge, or stuffed under it” (Werminskin, 1993, para.3). These scrapings are called mĂ©lange which forms the upper part of Mount Diablo. Between the mĂ©lange and uplands formed by continents these regions are filled with sea. In times of yore, all regions present in these ranges are under the sea. More overly eighty millions ego it is said that giant reptiles are present in these regions. Then after that all these regions are gnarled back into the sea. As these times passed many kinds of living species lived and died here. Some of these living species remain in the beds of these mud and sand. During the last twenty million years ego numerous kinds of rearrangement in geologic forces shows the way to creation of these mountains. Prescribed theory suggested “within the last four million years local fault activity brought a slab of old ocean floor into contact with the layered beds of sediment” (Werminskin, 1993, para.6). During the last million years ego some commanding compressive forces present in the land results the terra firma to crumple, which generate gigantic fold. “In the center of the fold, the resistant slab of old ocean floor material became exposed in bold relief as the softer surrounding strata were worn away” (Werminskin, 1993, para.6). This way Mount Diablo was born. Still geologist believes that this mountain is still rising and its evolution is not yet complete. Even now this mountain is still growing. Landslides of this region often get reshapes from time to time. Some sort of erosion results in bringing fresh sediments in to this region. Occurrence of earthquake and every plummeting rock strengthens the Mount Diablo’s dynamic nature.
Geological features and various types of rocks that formed in the mountain
There are different types of geological features present in these mountains. The uplands of the Mount Diablo consist of Franciscan a stratum, which is nearly about six thousand feet in thickness and is linked along “with intrusive serpentine and other somewhat metamorphosed igneous rocks” (Ross, 1940, p.35). The collection of rocks are normally alleged to be the Jurassic age. These rocks are all about roughly fifteen square miles in area. These are all surrounded by some sedimentary formations. The miscellanies of basaltic lava flows are found in the higher beds and inferior part of the Franciscan strata. The quicksilver deposits are also found in the above all these formations. The rocks are said to be very old but mountain is still young. The oceanic crust was represented over the coast range of ophiolite in which deposits of various sedimentary rocks are found. These coast range ophiolites are highly sheared, dissect, and thinned. These coast range ophiolite are not found to be in sequence order fault contacts are visible in between Franciscan and Great valley rocks. Besides this, great valley sequence of mountain consists of sandstones and mudstones. These stones are range from the age of Jurassic to cretaceous.
Landslides are another typical feature of Mount Diablo. The materials present in this are mainly of sandstone, which is entrenched in yellow as well as red clay. These landslides have topographic expression and whose limits are not visible. There are lots of crops, plants, wild flowers are present in these landslides. There are over seven hundred plant species found in this region. These are found abundant in the landslides. Varieties of bird species nearly two hundred bird species are found in this region. This includes sage and black chinned sparrow, humming bird, chaparral birds and different types of migrant birds. Apart from these different types of minerals are also copiously found in this region. The most important minerals hollow out on and around this mountain incorporate “mercury, diabase, graywacke, white sands, coal, blue schists, travertine, copper, and farther north and east, gas and oil “ (Guide to the geology of mount Diablo state part, n.d., para.42). Since the discovery of mercury it has been mined in northeast border of Mount Diablo. Mercury founded here are of two types they are red and black mercury sulfide. It has been found on the rock silica carbonate rock. The appearance of this rock is very spongy. Very good dimensions of stones are also available in this region and which can be used for building construction. Copper and minor amounts of gold and silver are also available in this region.
Various types of rocks
There are different types of rocks are formed in this region. They are Mount Diablo Ophiolite, Franciscan Complex, Great valley group and younger sedimentary groups. Mount Diablo Ophiolite rocks is one of the old ocean crust found on the Mount Diablo. These rocks were formed one hundred sixty five million years ego.
Mount Diablo Ophiolite Basalt is another type of rocks, which makes up the top most part of Mount Diablo. The color of this rock is greenish brown color. Soil found on this is reddish brown soil. Another form of rock found on this is Mount Diablo Diabase, which is made up of molten material. Mount Diablo Serpentinite is another frequently seen rock, which is derived from ocean crust. Color of these types of rocks is green to greenish color or in black color. Some parts of these rocks are seen in grayish orange color. There are some silica carbonate rocks, which are mainly called as altered Serpentinite, which are found along with mercury composition in its layers.
Franciscan Complex otherwise known as Mesozoic rocks. These are found in up and down of coastal regions. Thee types of rocks are always great mystery to geologists. The approximate age of these rocks are calculated as one hundred forty million years. Sheared types of sandstones along with paste like substance are found. These are called Franciscan mélange. Different types of rocks found under this are Franciscan basalt, chert, graywacke, shale and exotic rocks.
Great valley group and younger sedimentary groups are other types of rocks. Great valley groups are otherwise known as thick sedimentary rocks. This valley is mostly composed of “shale, sandstone and some conglomerates accumulating to a thickness of 60,000 feet near the western margin of the present day Great Valley, and then, in our area, thinning toward Mt. Diablo” (Guide to the geology of mount Diablo state part, n.d., para.23). Younger sedimentary rocks are found in central valley of California, which had been occurred, with results of flooded shallow sea.
Geological feature selected for research
The geological features selected for research is rocks. The most prevalent types of rocks found in this region are Great Valley Group. This has been clear from the map given below.
The sequences of rocks are composed of marine shale of deep water, sandstones, limestone, mudstones and some different masses of substances.
Age of selected geologic feature
The approximate age of selected geologic feature is nearly one hundred forty million years old. The methods used to determine the age of the rock is radiometric techniques, since this is best method to date sedimentary type rocks. This technique involves taking measurement of radioactive elements present in the rock.
Geologic event created choosing geological feature
The reason for choosing this geologic feature is lots of changes had taken place in the rocks and also this rocks is made up of different composite mineral samples from.
Process of plate tectonics related to the formation
“It was during this last phase that the Franciscan rocks, and overlying Great Valley strata, were folded by compressional forces associated with what is believed to be a blind thrust fault beneath the mountain” (Guide to the geology of mount Diablo state part, n.d., para.40). During these geographical processes a compressional asymmetric fold has been created and that moved to southwest. Thicknesses of these rocks are due to the rapid erosion. This resulted in the formation of great valley group.
The significance of igneous, sedimentary, and metamorphic rocks
The mixture of these rocks had been found through out these mountains. The igneous rocks are formed due to the melting of rocks. This has happen when rocks are buried deep into the earth. The high pressure and temperature results in the melting of this rocks. Basalt, granite are few examples. In case of sedimentary rocks these are formed when temperature and pressures are low in the surface of the earth. A variety of minerals are found on this type of rocks. Sandstone is an example. Due to intense pressure sometimes this igneous and sedimentary may get transform, which results in, metamorphic. During this new minerals are created. This is the reason for having abundant minerals in the mount Diablo.
Types of weathering and erosion processes that has most likely affected the physical appearance of the geological feature
Weathering and erosion process has greatly impact the physical appearance of the geological feature. Heat is considered to be principle factor of many metamorphic factors that taken place. Due to this many ions present in this migrate and recombine each other. High temperature results in speedy and efficiency of the process. Pressure also played an important role. Because of high pressure tightening of rocks happens. This made rocks harder and strength. The results of erosion process added more sediment to the rocks.
Significant of ocean in the region and process involved in creating the rocks
It is said that the formation of these mountains are due some kinds events that take place in the past. It is said that in the Jurassic age there has been ocean present in these regions and later due to some weather Calamities Ocean overflowed and made everything under the ocean. After this many years later formation of the rocks have been created with lots sediments dipped in to it.
Resources that is abundant in the region
There are plenty of resources available in this region. Resources include variety of plats, bird species, crops are all available in plenty. Apart from that one of the oak which are available in plenty and most important food source such as blue oak, coast live oak and valley oak. These are produced more in California and added economic value to the nation.
Conclusion
Geological feature that has been selected is rocks because it has got plenty of areas to research. Mainly Mount Diablo is made up of many types of rocks in which the great valley mountain has got more in it. This great valley has got much mystery behind it. Conquering such is very interesting and will add an advantage while exploring more details regarding this.
Reference
About mount Diablo. (n.d.). 2010, Web.
Baston, L.G. (1996). The mount Diablo information. Iraq Body Count. Web.
Guide to the geology of mount Diablo state part. (n.d.). Geology of MT. Diablo. 2010. Web.
Mount Diablo, California, USA. (2008). About.Com: Geology. Web.
Ross, P.C. (1940). Quick silver deposits of the mount Diablo district contra Costa county California. Geological Survey Publication. pp.31-54. Web.
Werminskin, J. (1993). Geology overview: Creating a mountain. Geology of MT. Diablo. Web.