However, impacts still occur across our solar system, but at a reduced rate. Figs. What process do you think formed Reuyl crater (marked B on Figure 5)? 17. A projectile (like the small plastic sphere) produced the crater in a laboratory hypervelocity impact experiment. In either case, the conditions of a hypervelocity impact and propagation of shock waves are crucial for the formation of these geologically extraordinary structures. Fig. In concurrence with this result, the crater age . Non-foliated textures have minerals that are not aligned. Terraces are a common feature of many large craters---for another example, look at the crater Theophilus. Texture will still be used but in a different sense than for igneous rocks. Justify your answer. 14): The crater is not much larger than the projectile. Determine and record the diameter of the caldera structure (include the over all caldera structure in this measurement). Source: https://news.discovery.com/earth/how-are-craters-formed.html, Center for Planetary Exploration (CPEx) Opens at Stony Brook University. Sometimes, impact structures are distinguished from impact craters by their weak morphological signature compared with a true crater. Very large impact craters greater than 300 kilometers (185 miles) across are called impact basins. Calcite readily reacts with a small drop of HCl. Since tectonic plate movements has erased much of Earths crater record, the answers to the lingering questions about crater formation and timelines lie in the exquisitely preserved craters on the moon. We can also see an inverted channel system, possibly ponded toward the southwest. This image shows a simple crater on Mars that has no central peak or terraces around its edges. Impact cratering is the excavation of a planet's surface when it is struck by a meteoroid. The three stages of impact crater formation. endobj
8. An extensive blanket of ejecta covers the area around the rim. Lastly, pyroclastic texture is composed of volcanic fragments. These craters are, however, decidedly not impact structures. 11. Although temperatures below freezing and low atmospheric pressures do not allow liquid water on the surface of Mars today, erosion processes involving running water were important on Mars in the past. > h] bjbj!! Craters produced by the collision of a meteorite with the Earth (or another planet or moon) are called impact craters. Procedures and Questions: Part 5
Finally, let's examine Apollinaris Patera and surrounding region. The Crater Maker can then drop the rock, and the Measurer . Procedures and Lab Questions to be Turned In: Part 1
Olympus Mons is a shield volcano 600 km in diameter, towering 25 km above the surrounding plain. | Explain your answer. The monument contains 55 cones with lava flows and 14 fissures, many of which have spatter cones. . NN `GF9A`U l8_g1g}=""Px2q$O@Y8)Oq-9O{2NW?`9:uMuBiO2qd]{%= LX'K 5 0 obj
Quartz has a hardness of 7 and is very difficult to scratch, even with a good quality knife blade. %PDF-1.4
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The Vredefort impact crater, about 100 kilometers (60 miles) from Johannesburg, South Africa, was formed just a little over 2 billion years ago. Are the craters you observe older or younger than the valleys? 3 0 obj
This means that the minerals in the rock are all aligned with each other. Below you will find a chart which defines the physical properties and provides the means for determining the physical property of a mineral sample. %
The texture of an igneous rock does not refer to the roughness or smoothness of the surface. The crater is about 1.2 kilometers (a little more than 0.5 miles) across and 200 meters (650 feet) deep. Igneous rocks can be identified by the determination of the composition and texture of the rock. From the geological map (Tanaka et al., 2014) it is evident that Reuyl crater formed over a Noachian-Hesperian dichotomy boundary surface. M8 aR Measure and record the east-west and north-south diameters. And of course there's the lake itself. In an introductory level lab it is impossible for us to determine these two aspects of a mineral. Essentially, the minerals are randomly oriented. <>
This means that our own planet is one of the youngest in the Solar System. As a rule of thumb, older surfaces have been exposed to impacting bodies (meteoroids, asteroids, and comets) for a longer period of time than younger surfaces. Something we dont understand very well on the geological side (of crater formation) is, we still find it difficult to determine the trajectory of impacting objects for most impact craters, Kring said. Marble is composed of calcite and will readily react to a small drop of HCl. How does the mass of the projectile affect the cratering process? Fig. Light colors, including white, light gray, tan and pink, indicate a felsic composition. 7) will result. The greater the mass of the impactor, the greater the size of crater. And although these are abundant on the . Posted by: Soderman/NLSI Staff stream
Different crystalline structures, or how the atoms and molecules are arranged, result in different minerals. Ds8d9B nNPS,*_y\v`/>wou__]ewPcLkUU$~z-S|lj O/#lr 9]_nc5u$9a4GVKwsaG|4ot6%?F3Xa:K1r=1\Sw Three processes help Earth keep its surface crater free. The Earth used to look just like that.. As lower levels of the lava start to cool, they are also pulled . Where were really going to get the answers the gold standards of answers is when we go back to the moon, Kring said. The general story of an impact follows a pretty predictable process. Code of Conduct Which is larger, and by how much? Keep track of the craters you measured. The crater is 2 kilometers (about 1 mile) wide. 4). This icy bedrock is potentially unstable, and some impact craters may relax or fade away to unrecognition due to water ice's volatility and weak but strongly temperature dependent rheology. The impact velocity was 1250 m/s, and the target (flour) sound /seismic velocity is estimated to have been about 100 m/s. Note the remarkable difference to the crater-projectile ratio in Fig. Anthracite coal is similar to bituminous coal. But Earth has several things the moon doesnt an atmosphere and liquid water that cause erosion. Tenoumer Crater. You will have to calculate an approximate image scale from the height of the peak in the foreground.) Larger, more forceful impact events will form complex craters in which the rock at the center of the crater rebounds from the downward pressure of the shock wave and uplifts into a mound-like formation. However, there are exceptions. The four major geologic processes (gradation, impact cratering, tectonism, and volcanism) each produce distinct landforms. Platy minerals tend to dominate. b.The process that I think formed apollinaris patera is Volcanism, this is because of its characteristics, such as the radial flow patterns, and basal scarp, a craters, large flow trending to the south, and the less complex caldera.. c.The process that I think formed Reuyl crater, is an Impact, the reason for this is by the ejecta pattern and central peak. Photo Policy The crater has been extensively eroded, but is believed to originally have been as much as 300 kilometers (185 miles) across. A stone-into-mud crater demonstrates the difference between it and a hypervelocity crater (Fig. Lake Toba in Sumatra, the largest volcanic structure on Earth, is an example of an enormous caldera that has filled with water over time. The diameter of the each miniature craters is 5 10 mm. Schistose foliation is composed of larger minerals that are visible to the unaided eye. must an impactor be to produce a given size impact structure? The GIF below shows the formation sequence of the model (a YouTube . In this way, all rock particles behind the expanding shock front are captured by both the compressive shock and the tensile rarefaction, and both combine into a vector of acceleration. The now existing bowl-shaped structure surrounded by an uplifted rim and a blanket of ejected material is termed the transient crater obviously indicating a continuation of the impact cratering process arriving in the modification stage. Suggest some ways in which the scarp around Olympus Mons might have formed. 03.04.10. The compression stage of crater formation involves that initial exchange of energy between the projectile and the impact area. endobj
16. Degraded craters -- Craters that have become eroded due to weathering, lava flows, impacting, or downslope movement of material. Justify your answer. Few, if any, crystals will be visible. The polar caps shrink during local summer and grow during local winter. I noticed the young crater has an odd shape, non-circular, almost diamond-shaped. Transcript (121 KB) Overview : Impact cratering is, arguably, the most important and fundamental geological process in the Solar System. The faster the incoming impactor, the larger the crater. Note: This is a large Adobe Acrobat PDF file: "craters_activity.pdf" (8.5 Mb), so you may want to download to your computer. Slaty cleavage is composed of platy minerals that are too small to see. 16. Earth and the other planets are constantly bombarded by tiny debris from space, much of which burns up in the atmosphere. The excavation stage of impact cratering. The keys to this definition are the chemical composition and the crystalline structure. Determination of this information is not easily accomplished in this lab. When first we see images of the famous one-kilometer (0.75-mile) bowl-shaped Barringer meteorite crater in Arizona (Fig. The crater was created instantly when a 50m, 150,000-ton meteor slammed into the desert about 50,000 years ago. <>>>
These temperatures are enough to more or less completely vaporize the impactor and a volume of the target rocks roughly comparable to the volume of the impactor, resulting in a giant expanding impact vapor plume. What are the different kinds of craters? Texture of sedimentary rocks in this lab will be taken to indicate origin or type of sediment found in the rock. For instance, the famous Chicxulub crater in Yucatan, Mexico, is thought to be the site of the meteor impact that instigated the K-T event, which wiped out the dinosaurs in a mass extinction that affected much of life on Earth. 1). Press, Oxford, 1989. - Lunar and Planetary Institute Arid climate and a lack of vegetation in the vicinity of Meteor Crater make it an excellent comparison site for similar-sized impact craters on Mars, Ramsey said. Justify your answer. The shock wave fractures the rock and excavates a large cavity (much larger than the impactor). Larger craters can have terraces, central peaks, and multiple rings. The Chicxulub crater in the Yucatan peninsula, Mexico, is not visible at the surface of the seafloor. d. Maadim Vallis is the channel in the southeast part of the photograph, marked C. Which of the four processes do you think formed Maadim Vallis? More about the doublet crater. Details from the Ascraeus channel (red), meandering across the surface of Mars. Hesperia Planum, showing bright windstreaks associated with some of the craters. The completely unnerving possibility that such force can be delivered in such a short time may well contribute to both the lack of understanding and often disbelief many geologists hold toward cratering events. The Moon lacks water, an atmosphere, and tectonic activity, three forces that erode Earth's surface and erase all but the most recent impacts. Before focusing on this important question, we have first to clarify the meaning of the term meteorite impact crater or impact structure. Continue doing this with harder or softer minerals from the kit until the hardness is determined.LusterCharacter of the light reflected by a mineral.Look at the sample to determine if the mineral is metallic in appearance (looks like a chunk of metal) or non-metallic (doesn't look like a chunk of metal).MagnetismElectromagnetic force generated by an object or electrical field.Use a magnet to determine if the magnet is attracted to the sample.Reaction to HClChemical interaction of hydrochloric acid and calcium carbonate (CaCO3).Place one small drop of HCl on a sample a watch for a reaction - effervesces (bubbles).Specific GravityRatio of the mass of a mineral to the mass of an equal volume of water.Generally not determined in an introductory lab. Craters can be used to determine the relative ages of Martian surface materials; in general, older surfaces have craters which are more numerous, larger, and more degraded than those on young surfaces. Intermediate compositions have an intermediate color, often gray or consisting of equal parts of dark and light mineral. Topography from echo sounder measurements. Describe the appearance and orientation of the windstreaks. In fact, the differences between craters provide a lot of information about how the craters formed, when they formed, and why. Based on the number and morphology of craters, is this a relatively old or young region of Mars? Image courtesy of V. L. Sharpton through the Lunar and Planetary Institute. Moreover, the principles of superposition and cross-cutting relations indicate that a feature which at least partly covers another feature is the younger. What process do you think formed Apollinaris Patera? Ma'adim Vallis (labeled C) is the channel in the southeastern part of the image. Igneous Rock Identification ChartCOMPOSITION
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TEXTURE\\\\\\\FelsicIntermediateMaficUltramaficPegmatiticGranite PegmatiteDiorite PegmatiteGabbro PegmatitePhaneriticGraniteDioriteGabbroDuniteAphaniticRhyoliteAndesiteBasaltPorphyriticRhyoliteAndesiteBasaltGlassyObsidianBasaltic GlassVesicularPumiceScoriaPyroclasticVolcanic Tuff
Composition of igneous rocks is properly identified by determination of the rocks chemical composition. Galileo Image (PIA00405), produced by the United States Geological Survey, courtesy of NASA. Pretty much any tiny dent made on the Moon's surface is going to stay there. What happens to the transient crater? 9. 19.) Statistically, impact trajectories most abundantly form an oblique 45 angle with the target surface. Impact basins are very large impact structures that are more than 300 kilometers (185 miles) in diameter. Albite has a chemical composition of NaAlSi3O8, while anorthite's chemical compositon is CaAl2Si2O8. Felsic compositions are rich in silica (SiO2). <>
The image to the left is a very simple, bowl shaped crater on the Moon and is typical of small craters that have formed relatively recently. Measure and record the width of the Ius Chasma. Geologic processes have not erased the craters with time. The impactor is shattered into small pieces and may melt or vaporize. and more. 6) Consider the relationship between Ma'adim Vallis and Gusev, the 160 km diameter crater marked C. Craters most often are circular. First, the impactor rushes toward the surface. Procedures and Questions: Part 3
Now we examine some Valleys west of Chryse Planitia. Some water probably seeped into the ground and is frozen there today as ice, and some likely escaped into space over time. Such outbursts can be violent enough that once the eruption is . ( ) + 2 3 i r M N g h p q r s t FZ@g(.T*+cv|JfhPR. eA@QBeDT_g[HDJX9D |! ~.5Svs)-b[E9it 9u{-rJ:Lcl F9"8 t(L)Npg:zS}"V|9)4ahyQ!rYkMd8{AY$
eCD:2BRPm-974WY\. The somewhat blurred contours are not surprising giventhe impact happened into water and a soft, water-saturated target rock. In the case of small transient craters, modifications are moderate. Very similar, but still different, therefore two different minerals. 3 strongly resemble meteorite impact craters exhibiting a central uplift like the Tycho impact crater on Earths moon (Fig. Determination of the actual chemical composition and crytalline structure of a mineral is difficult without the proper equipment. The circular shape is due to material flying out in all directions as a result of the explosion upon impact, not a result of the impactor having a circular shape (almost no impactors are spherical). in Reuyl crater located along the dichotomy boundary (west of Apollinaris Mons ). 13. Astronomy Gift Shop: http://www.astronomydvd.com/shop.aspx How were the Moon's craters and maria formed? Fig. Stresses can be caused by subsurface uplift or by the addition of mass (such as lava flows) that weigh down an area. You can help Wikipedia by expanding it. Craters come in two flavors: those that arent caused by asteroids or comets, impact craters, are formed by powerful volcanic explosions. Correspondingly, a zone of rock melt follows the vaporized zone, and when shock energy is further lowered rocks will only be heavily damaged (fractured, brecciated) with decreasing intensity. When an impactor strikes the solid surface of a planet, a shock wave spreads out from the site of the impact. The meter scale indicates water depth. In the upper part, the flow field enables the rock masses to escape as ejecta from the growing excavation cavity. This is clearly different from normal, endogenetic geological processes such as volcanism, earthquakes, tsunamis or other tectonic events. Reuyl, an early Hesperian crater, provides evidence for diverse fluvial events; Alluvial fans, channels, orthogonally superposed deposits, fan deposits with incised channels, and large deposits suggest fluvial activity; Two sinuous ridges associated with the alluvial fan on the crater floor are the oldest features of fluvial origin Name _____ COSMORPHOLOGY - May 2009 Geologic landforms Purpose: By studying aerial photographs you will learn to identify different kinds of geologic features based on their different morphologies and learn the processes involved in their formation. <>
How can you tell? Pegmatitic texture is composed of very large crystals (larger than 2-3 cm). 11 0 obj
These are not commonly tested for in an introductory lab. The so-called Meteor Crater in Arizona previously held the record for largest impact crater less than 100,000 years old; it's about 49,000 to 50,000 years old and measures 0.75 miles (1.2 km) in . Such outbursts can be violent enough that once the eruption is over, the volcano collapses in on its empty vacant magma chamber and forms a caldera, or volcanic crater. Through a combination of these principles, the relative ages of geologic features can be determined, and a sequence of geologic events developed. 1}bRX12AMAWQe'=u"tP]]!|SdX"uk3&~m?B?_OuG+ s6S
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"+.m Valleys on western Chryse Planitia near Viking 1 site. The extreme environmental shifts caused a mass extinction of 75% of Earth's species, including the dinosaurs. On relieving of pressure, there is an elastic rebound at the crater floor now hosting a layer of brecciated rocks. 5) Ma'adim Vallis is the channel in the southeast part of the photograph, marked D. What processes do you think formed Ma'adim Vallis? Kathleen Mark: Meteorite Craters. Reuyl is a crater in the Aeolis quadrangle of Mars, located at 9.8 south latitude and 193.2 west longitude. The crater has been extensively eroded, but is believed to originally have been as much as 300 kilometers (185 miles) across. and J.A. Individual craters are degraded or destroyed over time by erosional processes and further cratering. <>/XObject<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 17 0 R/Group<>/Tabs/S/StructParents 1>>
The composition of clastic sedimentary rocks is divided into three types - clay/silt, sand and gravel. On this Wikipedia the language links are at the top of the page across from the article title. Image from the Viking Orbiter, courtesy of the Lunar and Planetary Institute. Fig. (not recommended in an introductory lab - you don't know who has handled or licked the sample before you).Other PropertiesFluorescence, RadioactivityRequires special equipment such as a UV lamp and geiger counter. As mentioned above, the composition of most igneous rocks can be identified using this system, formally known as the Color Index. Foliated textures show a distinct planar character. 2. Small craters often are simple bowl-shaped depressions. The image shows ring-like structures that extend to about 280 kilometers (175 miles) from the center. }v)He|/7rw9>{W9qM~Zs.|9q7_9'o2p3kie V;\UXF}w1l`p!U,9#H{wx 0 ~
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13) hits the earth? For the following, you will use the knowledge from previous questions to identify Martian landforms and describe the geologic processes that created them. 2) we may think it somehow formed from an identical mechanism. What are some of Earth's famous impact craters? Tswaing Crater. This new crater candidate with fluvial morphological units preserved on the floor lead to understand the nature of fluvial processes . <>
b. 3. Fig. a depression formed by an impact (as of a meteorite). Ma'adim Vallis is the channel in the southeast part of the photograph, marked C. Which of the four processes do you think formed Ma'adim Vallis? 9 0 obj
HYPERLINK "../Honors227/Images/10_3.jpg"Figure 3. 13). Based on your observations, what is the probable order of occurrence of A, B, C, and D in Figure 5 (i.e., which came first, second, third, last)? The Measurer should measure from the ground to how high the rock is, and ask the Recorder to write down that height under the heading "Meteor 1, Trial 1". Computer simulations show that the modification process may already begin before standstill of the excavation leading to large-scale countermovement of rock masses. On propagating roughly hemispherically into the underground target rocks, shock wave energy diminishes and so does pressure and temperature. 15 0 obj
Reuyl Crater Central Peak, as seen by HiRISE. When an asteroidal or cometary object strikes a planetary surface, it is traveling typically at several tens of kilometres per secondmany times the speed of sound.A collision at such extreme speeds is called a hypervelocity impact. The larger size gives the foliation a slighly shiny appearance. 288 pp, The University of Arizona Press, Tucson, 1986. Justify your answer. Nrdlinger Ries. Describe the breakage as either irregular or conchoidal (has the appearance of broken glass)HardnessResistance to scratching or abrasion.Use minerals of known hardness from the Mohs Hardness Kits. This especially concerned also the vaporization of the impactor by shock-induced temperatures and, at that time, let the mining engineers helpless when they did not encounter the expected 50 m-diameter iron meteorite beneath the floor of the Barringer (Meteorite) crater. This, however, requires chemical equipment and apparatus that is unavailable in this lab. 20. Phyllitic foliation is composed of platy minerals that are slightly larger than those found in slaty cleavage, but generally are still too small to see with the unaided eye. These crater chains are formed when a comet, normally torn apart by tides, has many of its fragments collide into the planet or moon at nearly the same time. Chemical sedimentary rocks are identified by identifying the mineral from which they are composed. Impact craters allow scientists to study a planet's geological historyeven when the records are buried beneath the surface. Typically, materials from space hit Earth at about 20 kilometers (slightly more than 12 miles) per second. Gosses Bluff (Tnorala) Pingualuit Crater. Craters of the Moon is a large lava flow field with cinder cones, spatter cones, lava tubes, volcanic bombs and tree molds. These act together to break apart and wear down the ground. In the following, these three stages are illustrated and described in a somewhat simplified manner. It has some of the clearest water in the world, and the bottom lies nearly 2,000 feet below the surface, making it the deepest lake in the United States.You can gaze down on it from lookouts along the Rim Drive, part of the 500-mile-long Volcanic Legacy Scenic Byway.Or you can peer into its depths during a boat tour to Wizard Island (formed by a more . stream
Large crustal blocks were merging together to create the . Explain why you believe this is so. Fig. What influences the size and shape of a crater? 9). These are impact craters, each of which was formed when an asteroid or comet collided with the Moon's surface. How can craters be used to determine the age of a planet or moon? More about these experiments can be read on the Chiemgau impact website where a hypervelocity impact video may be downloaded. A comparable process is observed with the peculiar shock-deformed Buntsandstein conglomerates in Spain and is in more detail explainedHERE. If windstreaks are dust deposits formed downwind from the craters, what wind direction is indicated here? The size and shape of the crater and the amount of material excavated depends on factors such as the velocity and mass of the impacting body and the geology of the surface. Name _____ COSMORPHOLOGY - May 2009 Geologic landforms Purpose: By studying aerial photographs you will learn to identify different kinds of geologic features based on their different morphologies and learn the processes involved in their formation. Similar to some river systems on Earth, these Martian channels have a branching pattern. 20. Although Mars does not have plate tectonics like the Earth, there are many tectonic features that show its surface has been deformed. 7. April 8, 2015. . HYPERLINK "../Honors227/Images/10_4.jpg"Figure 4. Location: 24S, 245W. <>
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Do you think the surface of Olympus Mons is geologically old or young, compared to the surface of the Moon? Give evidence for your answer. The edges of these larger craters also may slump, creating terraces that step down into the crater. Tychos diameter is 85 km. It is true meteorites crashing as stones from the sky at free-fall velocity may in fact produce small craters in the ground similar to mud and hailstone craters. Explain why you believe the way you do. Multi-ring basin Mona Lisa on Venus. | 1). Therefore, crisp craters with upraised rims and steep sides are young, while less distinct and eroded craters with partial rims are probably older. -+eh5
L*]>;ppq 19. Sometimes the force of the impact is great enough to melt some of the local rock. On impact of a cosmic body, shock waves start from the contact point and propagate into both the underground target rocks and into the impactor. It is located along the north border of the Snake River Plain in Idaho. 245 pp, Oxford Univ. There is no other reasonable explanation for the occurrence of such a peculiar structure at the bottom of the glacial Lake Chiemsee. <>
Further identification of non-foliated rocks is dependent on the composition of the minerals or components in the rock. endstream
Barringer Crater (Meteor Crater) in Arizona, United States, is a simple crater created when a 50-meter-wide (160-foot-wide) iron-rich meteroid struck Earth's surface about 50,000 years ago a very recent event to a geologist. The contact and compression stage of impact cratering. 10. What process do you think formed Reuyl crater (marked B on Figure 11.5)? 19). Therefore, older surfaces have more impact craters. 2 0 obj
Wow, that's massive. Study area : Reuyl crater (9.6S, 166.9E) diam e-ter and depth is ~84 km and ~2.6 km respectively (Fig.1 a). Simple Craters . Partner, Earth and Space Science News for Educators. Which of the four geologic processes do you think formed this channel? (Viking MDIM Volume 4)
13. Copernicus is a large crater (93 kilometers or 60 miles wide) on the Moon. Oblong craters can be created by impacts striking the surface at a very low angle.