Chapter 15 : External Processes

With our observation of the Shawangunk formation, we see a sedimentary rock formation containing a range of grain size. Such sizes range from pebbles (3cm-5cm), fine-grain sand, and medium-grain sand. There is some grading towards the bottom left of the outcrop known as a reverse grading with some small cross beds present (Figure 2). The grading occurs towards a slight part of the outcrop where we see the grading beginning as fine grain sediments and working up to coarser grain. With moderate sorting we see variations of degree of sorting per bed. As the degree of sorting varies as does the sphericity. The sediment bedding is well seen ranging in sizes of +/--20 cm to 40 cm. This outcrop has thick beds as one can see the basic units with cracks in between each (Figure 3). With mostly tabular beds consisting of sub-angular, and sub-rounded sediments, this outcrop also consists of some ventricular beds (Figure 4). When looking at figure 4, we have a small space of a ventricular bed present. This is because the bed comes in, pinches thicker bedding,

Erosion is a process where natural forces like water, wind, ice, and gravity wear away rocks and soil. Erosion occurs at the Earth’s surface, and has no effect on the Earth’s mantle and core. Water erosion is the removal of soil particles by heavy rainfall or running water. “While the causes of erosion by water are generally natural, water erosion is usually caused by rainfall and runoff on a slope” (GEI Works Erosion Pollution). “The process of water erosion usually occurs on stream and river banks, sea shores and seaside cliffs” (Reference.com).

#17. The root system of an annual plant such as wheat root system is shallower compared to the root system of a perennial plant. The annual wheat plants need help from other substance and can’t rely on its own system to grown again every year. The perennial plants don’t need help from other substance at all because of its root system it does not need to start every year to grow again from seed.

The tiny pieces of rocks broken off by weathering are called sediment or alluvium. Erosion is the process of transportation of this sediment which on sea cliffs sediments becomes part of the seafloor and is washed away with the waves. The larger rocks that are broken off by sediment as shown in this picture are called scree or talus; scree builds up at the bottom of cliffs as the rocks tumble down, these piles are called scree slopes or talus piles.

Clastic sedimentary rocks are composed of fragments of older rocks that have been deposited and consolidated boulders greater than 25.6 cm cobbles 6.4 to 25.6 cm pebbles 2 mm to 6.4 cm sand 1/16 mm to 2 mm silt 1/256 mm to 1/16 mm clay less than 1/256 mm

The formation of Earth and other planetary bodies through the processes of condensation and accretion was essentially complete _____ years ago.

They are called transversal when pressure builds and the rock breaks the energy of the break

First of all chemical weathering is when there is rainwater that is able to react with mineral grains in rocks to form new minerals and also soluble salts. This type of reaction would usually occur when the water is slightly acidic. For this reaction to occur it needs water and would occur more rapidly at higher temperatures for example damp and warm climates would be the best for this reaction to occur. Chemical weathering usually happens more often in the spring because this is when it is more humid and hot outside and that is what chemical weathering needs for it to occur and also when it is usually hot or humid there will also be water.

Weathering is when the Earth’s surface rocks and minerals are broken down and dissolved. It can be caused by water, ice, acids, salt, plants, animals, and temperature changes. Weathering can be helpful by smoothing out rough areas of rock, creating soil by mixing tiny rock bits with remains from plants and animals. Weathering works with erosion to break down the earth’s surfaces.

Sinkholes are pits in the ground that form where water gathers with no drainage. The water weakens the ground under the surface and any weight on the affected area will collapse the ground.

Within the state of New York, landslides are classified as the downward movement of a slope and materials under the force of gravity (New York State Hazard Mitigation Plan, 2008). This definition also includes: a wide range of ground movement, such as rock falls, deep slope failure, shallow debris flows, natural rock, soil or artificial fill (New York State Hazard Mitigation Plan, 2008). Depending on the size and location of the landslide, landslides can be dangerous (Hyndman and Hyndman 2014). There are three mechanisms that initiate landslides. One mechanism is too much water. When water is added to a slope, soil becomes saturated and pore water pressure increases causing a slope to slide. A second mechanism is cutting the toe and oversteepening of the base. Removal or addition of material at the bottom of a landslide increases steepness of a slope. A steeper slope is less stable, increasing the likeliness of a landslide to occur. The third mechanism is adding material to the top of a slope, this also helps creates steeper

A landslide would be tabulated as a disintegrate mass of earth or rock to configurate a mountain, cliff or a summit.

Weather is created by the movement of air masses of different temperature and moisture content moving around the Earth’s atmosphere and interacting with each other.

The amount of rainfall and the temperature have a significant effect on the amount and depth if weathering occurs. The measure of precipitation decides the measure of water present for weathering. The temperature control the rate at which weathering happens. Weathering in the humid trophic more likely to be chemical type, under condition which favour chemical weathering, consistently high temperature and continually wet, the weathering reactions occur 3-4 times faster in the tropics than in temperate area. Many of the ancient regoliths of Australia were subject to chemical weathering for many million of years before the acidification of the continent, when it was mostly covered by humid rainforests that continued on from its time as part

     Igneous rocks are classified first by texture. This is broken down mainly into grain size. First there are intrusive, or plutonic igneous rocks. These types of rocks cool within the crust and forms large, visible crystals. The opposite would be extrusive, or volcanic rocks. These cool at the surface rapidly, forming small grains. A combination