Stratum 3

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

Holmes, Garnett, Bureau of Plant Industry United States, and Bureau of Chemistry and Soils United States. Soil Survey of The Yuma Area, Arizona-California. N.p.: Govt. print. off., 1905

Contain a distinctive top soil that is humose or peaty and a substratum starting at 40cm in depth which has been altered little (Avery, 1980; Buol, 1997). The soils do not contain a disturbed surface layer, the B horizon is not podzolic, weathered or argillic (Avery, 1980; Buol, 1997) and the soil profile is shallow (Ashman & Puri, 2002).

Extracted soil samples indicate simultaneous reduction of rainfall and occasional erosion. Both soil and sediment features show establishment of marked

Complete this week’s lab by filling in your responses to the questions from Geoscience Laboratory. Select answers are provided for you in red font to assist you with your lab work. Although you are only required to respond to the questions in this worksheet, you are encouraged to answer others from the text on your own.

Since Firm E’s take over nine years ago our car company has reported financial gains every year. Firm E continues to set the industry standard for car companies in many ways. Our company is poised for taking

Lutgens, F. K. & Tarbuck, E. J. (2011). Foundations of earth science (6th ed.). Upper Saddle River, NJ: Prentice

Many millions of years ago the Sierra Nevada was filled with ocean water until sediments began collecting and formed mountain ranges. Over a large period of time, the mountains began to wear out and became immersed in the ocean once again. Many different particles and materials began to make layers and created the first mountain system. After the Jurassic era, “…new strata were folded and crumpled and invaded by molten granite from below” (Beatty, 1943). A large

The basement rocks in the western Slave carton is older than 2.8 Ga and the known oldest rocks are the genesis found along the Acasta River which is about 3.6- 4.0 Ga old, which is estimated using the zircon dating (Isachsen & Bowring, 1994; Padgham,1992). Following by 2.8 - 3.5-Ga old genesis of Point Lake and genesis under the Yellowknife Greenstone belts, which exist over 3 Ga (Isachsen & Bowring, 1994; Padgham,1992). The major rock types include granitic to tonalitic genesis, migmatitic genesis and granodiorites, which have been deformed and metamorphosed (Fyson & Helmstaedt, 1988; Isachsen & Bowring, 1994; Padgham,1992). In the eastern Slave Craton, the basement is not confined but is correlated to the Nd-Pb isotopic boundaries

This site began its occupation during the Developed Periphrastic Period due to the pottery found in strata 25, 24, 23, and 22. The site was continually used until the Early Pleonastic which is found in strata 18, 17, and 16. The site was abandoned sometime between 1500 BC-800 BC because in stratum 16 there is Early Pleonastic pottery then in stratum 14 there is Late Chiastic pottery. Stratum 14 has Late Chiastic pottery, indicating the site has a population again. However, the stratum is clearly a hole that cuts through strata 15, 16, 17, and 18. In the stratum, burnt animal bones, seeds, broken pottery, and broken groundstones are found, possibly indicating nomadic people travelling through. The C-14 dates on the seeds are 720 ± 30 BC and

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,

Our third stop was along the interstate, right between two formations of Washita Valley. The formation on the north of us was represented by Pennsylvanian Collings Ranch Conglomerate (around 350 million years old), which is shown with blue color on the map and the formation on the south of us was represented by Ordovician Kindblade Limestone (around 450mil years old), shown by the pink color on the map. There is a huge time gap between these two formations. The Collings Ranch Conglomerate is outstandingly exposed along Interstate 35 near the top of Arbuckle Mountains. It was formed during late Pennsylvanian and is slightly younger than Devil’s Kitchen Conglomerate. Large size of grains, conglomerate boulders and cobbles, indicate high energy

1. The geology of Ontario is divided into three layers of rock. The first layer, Precambrian Canadian Shield rocks, is composed of mainly igneous and metamorphic rocks from the Precambrian Eon. This layer is the eldest at approximately 3-0.8x109 years old and is therefore the bottom-most layer (L). Although this layer is largely found in the Canadian Shield region of Ontario, glacial erratics from the Precambrian layer can be found at the Don Valley Brickyard (L). In the GTA, younger sediments and rocks cover the Precambrian rock layer (L). The second layer is Paleozoic rock, composed of sedimentary rocks
. It was deposited 600-400 million years

These techniques led to the discovery of the boundary between the two eras. A single thin layer of clay found within predominantly limestone rocks established this. By comparing the marine life found in, above, and below the clay, the marine life, like the dinosaurs, had been terribly affected by the extinction event. The percentage of life in the upper layers was dramatically lower than that in the lower. This was far more compelling than what was suggested by dinosaur’s fossils.