Similarities And Differences Of The Three Rondavels

Next, we can see that the rock displays a subtle porphyritic texture with plagioclase comprising the phenocrysts. The overall texture of the surrounding groundmass is granoblastic equigranular. Under thin section we also see a weakly defined foliation evidenced in the preferential alignment of actinolite grains and to a lesser extent chlorite grains. Undulose extinction is also observed in quartz indicating the rock was subject to deformation. The normalized quartz, alkali-feldspar, and plagioclase (QAP) values of this rock indicate that it is classified as a grano-diorite according to the IUGS QAPF classification system which is consistent with the hand sample interpretation.

The Ouachita Mountains were also created with the collision of Gondwana as it pushed together seafloor and are tilted or twisted folds of earth crust. Streams usually flow along the folds. Most of the mountains are made up of sandstone and shale from the bottom of the former sea. This region is usually known for unique quartz crystals,

The country rock was identified in the field to be a Meta-Limestone, but a more in-depth chemical analysis done by others classifies it as a dolostone of the Strath Suardal formation from the Durness group. (Digimap, 2017) (Goodenough et al. 2011)

The aim is to identify and associate landforms, rock types and soils to the natural environment and its plants and animals and also to investigate the history of the local environment, comprising human impacts over the last 50 years. The impact of human alterations to the environment includes increased soil erosion and changes in river flows.

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

The latest rocks in this region were formed in Pleistocene time as imperfectly consolidated gravel of river terraces and alluvial deposits of the

The land rose up and created a precipitous eastern edge of the batholith and a gentle western edge. 10 million years ago, uplift, which is the vertical rise of Earth’s surface due to natural causes, started to occur and accelerated quickly. Soon, the Sierra Nevada Mountain Range that we know today towered 14,000 feet in elevation. Throughout uplift, cracks formed in the granite of the mountains. They formed due to the pressure that came with the uplift. The erosion that stripped away most of the overlying rocks caused the remaining rock to expand and crack. These cracks are still forming today and they provide a template for future erosion.

At Laurel Hill Duke Forest there is a large granodiorite cliff adjacent to a river on one side. This cliff is not smooth and has several parallel fractures instead of one steep slope. Observations of this cliff were taken in order to gather data and find possible explanations for why this cliff is where it is located and why the river adjacent to it follows a V-shaped path. One observation was that the range of the strikes and dips of the fractures facing river were all near parallel ranging from strike of 170-190 degrees and dips ranging from 70-90 degrees. There were other fractures oriented differently on other sides of the outcrop. Also, the surface of the outcrop was highly weathered in some parts where the rock type was not distinguishable without using a rock hammer and had moss growing over it.

There are many climates all over the world. Many climates have similar weather patterns. The Marine West Coast climate and the Humid Continental climate are in different regions. Both of these climates are similar yet different.

Majority of the Canadian Shield is made up of metamorphic and igneous rocks. The rocks

Rock suitable for the production of stone tools is fOW1don every mountain range, and in creek beds as cobbles and pebbles. Two surveys have been conducted in the area. Horned Toad Consultants conducted extensive judgemental surveys during initial impact assessment, concentrating on the grasslands of the Little Bison valley, two arbitrarily chosen tributary valleys (Cripple Creek and Silver Creek), one cirque (below Smith Peak) and the Inverness Plateau. Four site types were defined. Camp sites contain a wide range of artifact types and fire broken rock. Kill sites contain a restricted range of artifacts (mainly projectile points) and large quantities of bone. Lithic scatters are small sites with no diagnostic artifacts. Quarries have large quantities of debitage, usually associated with shallow pits dug into bedrock. The distribution of sites and diagnostic artifacts is shown in Figure 8.1. Recently R. Bootheel undertook a survey of the area using random sampling techniques. Although her M.A. thesis is still being written, she has commented on the previous survey as follows:

At the nearby valley wall, there is a distribution of rock lithology including mostly Limestone. The roundness of the samples is all angular, with a mean size of 8.325 cm in diameter. However, the stream bank has more clastic rock samples which have a rounder shape and a smaller mean size of 7.975 cm. These contrasting sections are between alluvium and colluvium data where the alluvium

One piece of this history is the subsurface Paleozoic rocks. Paleozoic rocks are for the most part hidden in the Park despite being in the Colorado Plateau, which is likely due to both erosion, and it being buried in other various rocks. Next is the deposition of the Moenkopi Formation during the early Triassic time period. When North America was still apart of Pangea, the area that was the Colorado Plateau was located within close range of the Equator. 300-600 feet of sand and mud were accumulated during this time, with marine life being included which tells Geologists that the sea sometimes was in the area. The climate at the time was warm, with varying times of humid and dry spells. There is very few beds of the Moenkopi Formation left in the area once again due to erosion. Third is the deposition of the Shinarump Member of the Chinle Formation. This basal conglomerate was deposited on top of the Moenkopi Formation. It is made up of gravel and sand, which indicates that there was water depositing it. The Shinarump Member also averages between 35-50 feet thick. Next in the geological history is the deposition of Chinle beds later in the Triassic time period. When the sea regressed to the west of the area, a large plain was left behind. As the climate changed, so did the environment. Soon grasslands and marshes began to form in the area. During this time hundreds of feet of shaly material accumulated which formed both the Lower Petrified Forest Member and the Upper Petrified Forest Member. In some parts, these two members are separated by the Sonsela Sandstone Member, composed of the most petrified wood compared to all other rock units featured in the Park. The Owl Rock Member is at the top of the Chinle Formation, and completes it. Near the end of the Triassic time period, tectonic activity was occurring heavily in the Arizona basin. In the western sea at this time a chain of volcanoes erupted,

The third and topmost layer of geological deposits is the Pleistocene sediment, from the Quaternary Period, which can date up to 1.7 million years old (L). This layer contains sediments of Holocene from ten thousand years ago as well as Pleistocene from 1.7MY to 10KY(L). Continent wide ice sheets deposited the glacial sediments during numerous ice ages (DVLR) and can be seen at Don Valley Brickyard. The York Till is above the bedrock, and was left 135,00 years ago by an Illinoian ice sheet. Above the till is the 80,000-year-old Don Formation that was caused by the Sangamon Interglacial, and indicates climate change by the alternation of sand and mud. Above the Don Formation, all other deposits are from the Wisconsin Glaciation. The Scarborough Formation consists of clay and then sands, and was formed 60,000 years ago. Above this is the Sunnybrook Drift and the Thorncliffe Formation from 45,000 years ago consisting of seminary

The Plains take second place! This region was created when soils by rivers and lakes from the Canadian Shield were deposited at this regions edge. In addition, sedimentary rock was formed from these deposits, which became huge areas of flat, fertile lands, river valleys, and rolling hills. To add, there are three flat levels and each consists of hills, cliffs, low mountains, forests, wide river valleys, and sand