...million years ago. His theory of continental drift was met with skepticism in the scientific community. [pic] 1. Describe three forms of evidence Wegener used to support his ideas of continental drift. Wegener used landorms, climate, and fossils to support his theory of continental drift. He said that when it came to landforms all the continents seemed to fit like a “jigsaw puzzle”. Even went as as far to say the mountain ranges seemed to line up as well. Wegener said that the same fossils and rock from one continent would end up on a different continent. For instance a fossil found in Africa would also be found in South America. When it came to climate, Wegener said that some fossils did not match the climate. For instance, there a glacier scratches in South Africa. 2. Years later, the continental drift theory reemerged as plate tectonic theory, with two additional pieces of evidence. [pic] [pic] Refer to the images above. Discuss in detail the two pieces of additional evidence that supported Wegener’s theory, now known as the theory of plate tectonics. The first image shows the ages of the banded rocks on the mid-atlantic range. By looking at the image you can see the the middle (yellow streak) is the youngest while the rock on the outer edges are the oldest showing that the seafloor has ben spreading over time. The second image shows surface motion and how all the points on the same plate...
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...9/18/12 Oct 2nd first exam! Continental crust: felsic (has most silica), less dense Oceanic crust: mafic, more dense Deep in earth crust you’ll find Diorite. Closer to the surface of the continental crust you’ll find Granite. In earth Mantle: Peridotite, Garnet Peridotite, both are iron rich. Seismic Waves: P Wave: can travel through molten iron (outer core) S wave: cant travel through outer core Outer Core: liquid, iron and nickel Inner Core: solid, iron and nickel -Increase in P-wave velocity and increase in density -Keep in mind: Moho Drifting Continents and Spreading Seas Plate Tectonics: Unifying theory of geology developed in 1960’s, outer layer of Earth’s crust (lithosphere, lito = rock)consists of separate plates that move around. Explains locations of: earthquakes, volcanoes, mountain belts Antonio Snider-Pelleginer: says its all together (the plate) Alfred Wegener(1880-1930): first proposed the Hypothesis of Continetal drift: The Origin of the Continents and Oceans (1915) **What evidence supported Wegener’s continental drift hypothesis?** 1. Obvious fit of continents 2. Evidence for the distribution of glaciers a. Glaciation (260-280 Ma) Striations: direction, till deposits: perimeter. If continents were connected, one large ice cap explains these observations. Climate belts from ancient environments seem to match across continents. 3. Distribution of fossils a. Each continent has unique assemblage...
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...They were found at the same time as well. This shows North America and Europe might’ve been connected at one point in time. This does make sense with the theory because the two continents do fit together like a puzzle piece. V. Effects From Pangaea to the World Today Believe it or not, Pangaea actually effected the world today. The reconfiguration of the continents caused: sea level changes, oceanic and atmospheric changes, and global warming. During the Mesozoic Era oceanic ridges were formed. Before the breakups occurred, the mantle was warming up. This energy was spread across the surface of the Earth as heat energy and this caused ocean warming. The sea level then rose because of the expansion of water. In addition, ice sheets melted because of the atmospheric warning. The effect of the sheets melting would’ve taken weight off of the continents and a sea-level change. When Pangaea began to break-up various seaways opened and closed. In 3 Ma when the North and South America continents joined, the equatorial currents that passed from the Atlantic to the Pacific stopped. This drove more...
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...University of Phoenix Material Effects of the Motions of Tectonic Plates Worksheet From Visualizing Earth Science, by Merali, Z., and Skinner, B. J, 2009, Hoboken, NJ: Wiley. Copyright 2009 by Wiley. Adapted with permission. Part 1 This diagram was similar to one Alfred Wegener drew to show the distribution of continents 300 million years ago. His theory of continental drift was met with skepticism in the scientific community. 1. Describe three forms of evidence Wegener used to support his ideas of continental drift. • Continental Margins (Visually land masses fit together like a puzzle) • Rock layers (similarity on the coast lines as well in a different continent • Fossil evidence (How some animals were identical on the other side of the world, and how tropical plants were found in Arctic regions. 2. Years later, the continental drift theory reemerged as plate tectonic theory, with two additional pieces of evidence. Refer to the images above. Discuss in detail the two pieces of additional evidence that supported Wegener’s theory, now known as the theory of plate tectonics. • One additional piece of evidence was the mapping of the ocean sea floor. When all these investigations about the ocean sea floor were given to scientist, a new light in the composition of the rocks and their distribution was discovered. Wegener's ideas started now to make sense for most geologists, the saddest part is that at this time Wegener was already dead so he could...
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...Continental Drift A German geologist and meteorologist named Alfred Wegener introduced a theory in 1915 that the Earth’s crust is slowly drifting using fossil records as his supporting evidence. Wegeners idea was Earth was one big continent 200 million years ago, he called it Pangaea, which means “All earth”. Albert Wegener published a book about this theory in 1915 called, On the Origin of Continents and Oceans. An Austrian geologist named Eduard Seuss was the first to find that there had once been a land bridge that connecting South America, Africa, India, Australia, and Antarctica, he named the large piece of land Gondwanaland, the southern part of the huge continent Pangaea after it broke up during the Jurassic period. Seuss’s theory is supported by the fossil plants that are found throughout India, South America, southern Africa, Australia, and Antarctica. Fossils of the first marine reptiles known as Mesosaurus that are even older than dinosaurs were found in South America and South Africa. With the discovery of the fossil in two different locations across water and the study of sedimentation and fossil plant in these southern continents led a South African scientist named Alexander duToit to supporting the idea that at one point all of the continents were once together and have drifted apart like Albert Wegener theorized. In 1960, a theory was made explaining the movement of the Earth’s plates and explains the causes of volcanoes, oceanic trenches, mountain...
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...those of the Santa Catarina system in Brazil”(University of California Museum of Paleontology, 2004-2010). His theory was not accepted at first, it took decades for other scientists to see what he had originally tried to explain when publishing his theory in 1915. The reason his theory was not taken seriously is because there was no explanation for how the continents would move. Because the continents do not fit from shore line to shore line we have to look below the sea level and see where they fit best. The shore line do not stop at the water’s edge they slope into the water, this is called the continental shelf. Down about 100 meters there is a shelf break called the continental slope this is where the true edges of the continents can be found. “In Wegener’s time, the technique of radiometric dating was just being developed, so it was not easy to determine the exact age of a rock” (Murck, B. W., Skinner, B. J., & Mackenzie, D, 2006). Now we know that there are many similarities between the continents on both sides of the ocean. In 1929, Arthur Holmes agreed with Wegener, Holmes theorized that the source of continental drift could be the molten mantle beneath the earth's crust experiences thermal convection and that the movement of these...
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...water came from. According to the text, some water were in the materials that formed Earth. That water was released as steam from volcanoes. The text also states that more water could have came from outside sources such as comets and meteorites. Discuss the origin of the salinity of seawater and how the ocean maintains salinity. Chemical weathering of rock and volcanic eruptions are some of the sources that are involved in the salinity of seawater. Evaporation of surface water and freezing of seawater makes seawater saltier. While rain, snow, and river water make it less salty. 2 Part 2 Surface currents obtain their energy from the wind blowing over the surface waters. The currents do not exactly follow the wind direction because of an apparent force known as the Coriolis force. Using Figure 12.11 from the text, briefly explain surface currents of the world ocean and how the Coriolis force affects this movement in the Northern and Southern Hemispheres. Surface currents of the world are the cold western boundary currents, the North Atlantic drift, and the Circumpolar current. The Cold western boundary currents are in the Northern Hemisphere, where there are continental boundaries in high latitudes. The cold equatorward currents flow along the east side of the continents. There they meet...
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...Structure and composition of the Earth The overall composition of the Earth is very similar to that of meteorites, and because of this, it is thought that the Earth originally formed from Planetesimals composed largely of metallic iron and silicates. What makes Earth unique? Soon after the Earth formed, unique processes occurred - division into metallic core, silicate mantle and crust - which, along with surface water, made it different from the other planets in our Solar System. The formation of the early mantle was important as it consisted primarily of ferromagnesium silicate minerals, some of which contained water as an essential component (e.g. amphibole group minerals). Water-bearing magmas (molten rock) from deep in the lower mantle then rose towards the surface (being liquid, they were lighter than the surrounding solid rock) and emerged as volcanic eruptions. The Earth's atmosphere and hydrosphere developed from the degassing (loss of gaseous elements such as carbon, hydrogen and oxygen) of the early-formed core and mantle during this volcanic activity. In the present, abundant gases are still released from the Earth during volcanic eruptions and these are mainly composed of water (77%), carbon dioxide (12%), sulfur dioxide (7%), and nitrogen (3%), with minor amounts of hydrogen, carbon monoxide, sulfur, chlorine and argon. The Earth can be divided into two main parts. Atmosphere: measured from the surface of the Earth upwards to 150 km (anything above this...
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...about Earth’s interior, including meteorites, volcanic rock inclusions from the mantle, and laboratory experiments; however, we gain the most insight about Earth’s interior from the study of the behavior of seismic waves. 2. How do we know that the Earth’s interior is layered? We know that Earth’s interior is layered because seismic waves (S and P waves) refract and reflect at layer boundaries. Earth’s changing magnetic field also provides evidence of a layered Earth, because it indicates that some portion of Earth’s interior is composed of liquid metal, since fluid motions within this molten layer are thought to generate Earth’s magnetic field. 3. How do we know that the outer core is liquid? S-waves shadow zones (the lack of direct S wave energy arriving to regions located on the opposite side of the Earth from the earthquake focus) are the best evidence that the outer core is liquid. 4. How do we know that the mantle is solid? Where does Earth’s magnetic field originate? A solid mantle is indicated by the fact that S waves (which can only pass through solid material) can pass through the mantle. 5. Has Earth’s magnetic field always been oriented toward the present-day North Pole? Explain. No, studies of seafloor rocks and continental volcanic rocks indicate that Earth’s magnetic field reverses itself at random intervals. During periods of reversed magnetic polarity, the magnetic field is oriented opposite to its orientation during periods of normal polarity...
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...Evidence which supports the statement Volcanic events are typically events which occur as a direct result of a volcano, where debris and molten rock are both extruded and intruded during an eruption. The plate tectonic theory was developed by Alfred Wegener in 1912, however initially his theory of how the plates all ‘fit together’ was ignored as there was simply not enough evidence. After technology had significantly advanced later in the 20th Century, the theory was developed further by several scientists. This theory suggests that the crust is split into a number of plates, all of which float on molten mantle rock and are constantly moving on the Earth’s surface. We are also now aware that there are two types of plate, oceanic and continental and it is the movement of these two plates that can cause both volcanic and seismic events. However these events are not the only pieces of evidence that prove the plate tectonic theory is valid; there are many other factors which include sea-floor spreading and fossil distribution. Pyroclastic materials and molten magma escape the mantle and emerge above the Earth’s crust through volcanos. All of Earth’s active volcanos are distributed in clusters around the pacific ocean, southern Europe, the east coast of Africa and through the Atlantic Ocean. These specific locations are all as a result of the nearby constructive and destructive tectonic plate boundaries, this is known as ‘The Ring of Fire’. It is named so because of the large...
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...Study Guide: Midterm Exam Concentrate your studies in the following areas. Questions for the Midterm Exam will come principally from this material. Lutgens and Tarbuck Textbook: Minerals (Chapter 1) * Know the definition of a mineral. a solid inorganic substance of natural occurrence * Know the basic definition of a rock. the solid mineral material forming part of the surface of the earth and other similar planets, exposed on the surface or underlying the soil or oceans * Know how atoms of the same element are related. Atoms of the same element must have the same number of protons which is the atomic number. What do they have in common? They all have protons * Know definitions for the following terms: valence electrons, an electron of an atom, located in the outermost shell (valence shell) of the atom, that can be transferred to or shared with another atom. An electron in one of the outer shells of an atom that can participate in forming chemical bonds with other atoms nucleus, the central and most important part of an object, movement, or group, forming the basis for its activity and growth. atom, the basic unit of a chemical element element, ion, and chemical compound. * Know the difference between ionic and covalent bonds. Ionic compounds contain a metal cation bonded to a nonmetal anion. This means that the first element in the compound's name and formula is to the left of the zig-zag line on the periodic table above. Covalent compounds contain NO...
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...1. Introduction Rural development is South Africa’s priority to achieving the millennium development goals (MDGs). The millennium development goals aim at cutting poverty by 50% by the year 2015. In South Africa about 40% of the country’s population resides in rural areas and they directly or indirectly depend on the land that they live in. Agriculture plays a significant role in the country’s economy, contributing in 2000 about 2.9% of GDP, 10% of formal employment and 10% of the total value of exports. Agriculture as a percentage of GDP has decreased over past four decades, currently contributing around 2%. This implies that the economy is maturing, moving towards the secondary and tertiary sectors. However, farming remains vitally important to the economy with 638 000 people formally employed (Statistics SA, 2012 Q2) – although it’s estimated that around 8,5-million people are directly or indirectly dependent on agriculture for their employment and income. However, global climate change will affect the government’s efforts to alleviate poverty and fast-track development in rural areas. Definition of terms Global warming: refers to the increased temperature of Earth's surface, including land, water and near-surface air. Climate change: means a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods (UNFCCC)...
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...the focus and epicenter of an earthquake. Which is located at the source of the earthquake? Which is located on the surface of the earth directly above the source? --Focus=Earthquakes tend to occur along preexisting faults where internal stresses have caused the crustal rocks to rupture or break into two or more units. The location where slippage begins is called the hypocenter, or focus. --Epicenter=The point on Earth’s surface directly above the hypocenter * Understand the concept of elastic rebound. What is it? How are earthquakes produced via elastic rebound? * --Elastic rebound=At some point, the stress along the fault overcomes the frictional resistance, and slip initiates. Slippage allows the deformed ( bent) rock to “ snap back” to its original, stress- free, shape; a series of earthquake waves radiate as it slides. Reid termed the “ spring-ing back” elastic rebound because the rock behaves elastically, much like a stretched rubber band does when it is released. * Know the three basic types of seismic waves (i.e., P waves, S waves, and surface waves). What is the particle motion in each type of wave (e.g., particles move parallel to the direction of travel in P waves)? Which type of wave travels the fastest? Which type of wave is the slowest? Which type of wave arrives first at a seismic station? Which type of wave is the last to arrive at a seismic station? Which type of wave causes the most...
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...long intervals of time. Remember that small changes over millions of years are the framework for evolving complexity from simplicity. Summary of concepts and idea An initial step in covering this material is an understanding of the different types of cells (prokaryotic, eukaryotic animal and plant), their differences, and their place in the phylogeny of life. 1. Information from pre-class reading, Bioflix animations and briefly summarized in class discusses the fundamental components of the prokaryotic and eukaryotic cells. You need to know the differences and understand the basic functions of the cellular components as cells as they are the fundamental units of life. 2. The 3 domain tree of life is a modern version of how we believe life to have arisen from a common ancestor(s) through branch points very early in the life history of the Earth into Bacteria (3.8 BYA) and Archea (3.7 BYA)- the prokaryotes. Single celled Eukaryotes may have appeared between 2.1-2.8 BYA and branched more recently from the Archea than from the...
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...the differences between water and alcohol 1. you could try burning. alcohol is extremely flammable, whereas water will put out a fire 2. alcohol has a smell, water does not. 3. alcohol will evaporate quickly, water will just sit. 4. pH test, water will be neutral, alcohol will be acidic. 5. you could dye one of them with food coloring and mix them. the alcohol will be the one on the top, because alcohol is less dense than water. 2. Water: molecular mass of 18.015, density of 1 g/cm³ at 4°C, refractive index of 1.3330, solid form less dense than the liquid form, amphoteric properties, boiling point of 100°C at atmospheric pressure, not flammable. Alcohol: molecular mass of 46.07, density of 0.789 g/cm³, refractive index of 1.36242, solid denser than the liquid, slightly more acidic than water, boiling point of 78°C at atmospheric pressure, highly flammable Water (along with life) is what sets our planet apart from our neighbors and it is the topic of this chapter. The hydrosphere is the watery part of the Earth, but this is a little misleading since it gives the impression that there is one place where water occurs. Instead, water is everywhere, or nearly so. Water is present in the atmosphere, in the form of vapor, liquid, and solid. It is tied up in rocks, locked away in the crystal lattices of minerals that make up rocks; it occurs in the innumerable small pore spaces of rocks, from the surface to depths greater than 5 km. Water is also tied up in living...
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