9. Statistically, impact trajectories most abundantly form an oblique 45 angle with the target surface. Gypsum is relatively soft (Hardness =2) and can be scratched easily with a fingernail. Measure and record the width of the Ius Chasma. Chemical sedimentary rocks are identified by identifying the mineral from which they are composed. : Impact cratering. 18. The faster the incoming impactor, the larger the crater. Small craters often are simple bowl-shaped depressions. How the atoms and molecules are arranged and the strength of the bonding between the atoms result in different physical properties for different minerals. First, the impactor rushes toward the surface. {u/
8`&_@ug,jbAM$[$oPocqM9K'5u"gY2;!1Nb$NfMc,cl9{=ZY6m#v]b1$m|"^K)Ks7q~B-=Cdl/)q&eHdiT) %Iwd`y\*/[Cr|R>/cRN]UyYIcF8`wiaV>bzw]'b+DZbV;zdge4e=00%9)q@B|~1QV, V=~ERZRm -Y Valleys on western Chryse Planitia near Viking 1 site. This planar character can be flat like a piece of slate or folded. How can craters be used to determine the age of a planet or moon? Even the crater-covered moon might be a chip off old Earths block, an enormous shard shot into orbit following a giant impact event. T U ; = B } ~ x z h_X B*
CJ ph h_X B* ph Craters produced by the collision of a meteorite with the Earth (or another planet or moon) are called impact craters. Reuyl is a crater in the Aeolis quadrangle of Mars, located at 9.8 south latitude and 193.2 west longitude. Fig. The crater has been extensively eroded, but is believed to originally have been as much as 300 kilometers (185 miles) across. 4. 12 0 obj
This depends on how large the crater is. Justify your answer? Limestone may or may not contain fossils. Simple craters are small bowl-shaped, smooth-walled craters (the maximum size limit depends on the planet). You will have to calculate an approximate image scale from the height of the peak in the foreground.) Geologic processes have not erased the craters with time. During an impact, buried material is ejected while outward pressure pushes the rock at the crater's edge upward, forming a rim. This, however, requires chemical equipment and apparatus that is unavailable in this lab. This will result in the formation of central uplifts and ring systems, and we may now refer to these as central-uplift or central-peak craters, peak-ring craters or multi-ring craters establishing the group of so-called complex impact craters or complex impact structures (Fig. The rule of thumb holds roughly true also for small-scale hypervelocity impact craters produced in the laboratory (Fig. 6) Consider the relationship between Ma'adim Vallis and Gusev, the 160 km diameter crater marked C. It has a raised rim around the edge, and nice, sharp features. Tswaing Crater. Scientists record the size and number of impact craters and how eroded they are to determine the ages and histories of different planetary surfaces. What process do you think formed Reuyl crater (marked B on Figure 5)? Justify your answer. Fig. Sand and dust particles carried by the wind form dunes and windstreaks. This crater is about 20 kilometers (12 miles) across and has a large central peak and terraces around its rim. Very large impact craters greater than 300 kilometers (185 miles) across are called impact basins. HYPERLINK "../Honors227/Images/10_3.jpg"Figure 3. What happens when an impactor hits? endobj
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L*]>;ppq Although Mars does not have plate tectonics like the Earth, there are many tectonic features that show its surface has been deformed. Context Image. January 2014; Quartzite is composed of quartz sand grains. Reuyl Crater is approximately 86 kilometers in diameter and was named after Dirk Reuyl, a Dutch-American physicist and astronomer (19061972) who made astronomical measurements of the diameter . endobj
What happens if a comet or a very low-density, loosely bound asteroid (like Mathilde asteroid, Fig. Do you think the surface of Olympus Mons is geologically old or young, compared to the surface of the Moon? endobj
11. Metamorphic Rock Identification ChartTEXTUREFOLIATIONCOMPOSITIONTYPEPARENT ROCKROCK NAMEFoliatedslatymicaRegionalMudstoneSlatephylliticquartz, mica, chloriteRegionalMudstonePhylliteschistosemica, quartzRegionalSlateSchistschistoseamphibole, plagioclaseRegionalBasalt or GabbroAmphibolitegneissic bandingfeldspar, mica, quartzRegionalSchistGneissNon-FoliatedcarbonContact or RegionalBituminous CoalAnthracite Coalquartz, rock fragmentsContact or RegionalConglomerateMetaconglomeratecalciteContact or RegionalLimestoneMarblequartzContact or RegionalSandstoneQuartzite
Mars Surface Introduction
In many ways Mars is similar to Earth. Measure and record the east-west and north-south diameters. The compression stage of crater formation involves that initial exchange of energy between the projectile and the impact area. endobj
Given such drastic, far-reaching outcomes of space rock impacts, Kring said that studying crater formation holds the answer to understand not only how life on Earth began but also how it could be wiped away again in a future, perhaps inevitable, K-T event. endobj
Slaty cleavage is composed of platy minerals that are too small to see. There is no other reasonable explanation for the occurrence of such a peculiar structure at the bottom of the glacial Lake Chiemsee. (Viking MDIM mosaic 211-5360)
1. Craters are roughly circular, excavated holes made by impact events. On relieving of pressure, there is an elastic rebound at the crater floor now hosting a layer of brecciated rocks. ), 1987, Glossary of Geology. endobj
A mystery concerning water on Mars is "Where did it go?" a depression formed by an impact (as of a meteorite). It is the oldest and largest impact crater recognized on Earth's surface. 8. The somewhat blurred contours are not surprising giventhe impact happened into water and a soft, water-saturated target rock. 17 0 obj
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eCD:2BRPm-974WY\. Procedures and Questions: Part 4
The Hesperia region in the southern hemisphere consists of cratered plains which have been modified by aeolian processes. 14. Impact cratering is the excavation of a planet's surface when it is struck by a meteoroid. 12. This suggests that the transient crater collapse in the modification stage is largely driven by gravity (gMoon ~ 1/6 gEarth). The origins of Uluru (and Kata Tjuta) date back about 500 million years, to around the same time the Australian continent was formed. 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. 2. HYPERLINK "../Honors227/Images/10_5.jpg"Figure 5. It is colder inside some craters near the lunar poles than it is on the surface of Pluto (25K, or -415F). by lava flows that obscured the older craters. 14 0 obj
As lower levels of the lava start to cool, they are also pulled . On this Wikipedia the language links are at the top of the page across from the article title. More about these experiments can be read on the Chiemgau impact website where a hypervelocity impact video may be downloaded. Kaali Crater Field. Elastic rebound and collapse cause the excavation trajectories to go into reverse in a way, and the rock masses tend to move upwards and centripetally thus, accompanied by large-scale downfaulting, largely backfilling the transient crater. Mafic rocks may contain light colored minerals as well. Complex craters are large craters with complicated features. Apart from the distinct role rarefactions waves play in the formation of the excavation flow field, they are especially relevant geologically. XX=S;K]3:V-j ,bxHeM?qaZ] R*Jf]x-Tfymoy{!TX&THH9C]NXg 1. The model crater developed a nice central peak as well as terraced margins. Earth Rocks Introduction
Minerals are defined as naturally occurring, inorganic, solids with a definite chemical composition and a regular, internal crystalline structure. (Viking mosaic P-17698)
9. Not a model for impact crater formation. Sand is clasts between 1/16 and 2 mm in size, and gravel is greater than 2 mm. Hailstones and even raindrops may produce on harder ground small craters as well (Fig. 8. Terms of Use, Copyright document.write(new Date().getFullYear()); What is the texture of the ejecta flow labeled A? At the edges of lunar maria, there are often damaged walls of craters formed before the maria. 21. Check Pages 101-150 of Planetary_Geology in the flip PDF version. How looks an impact crater that was produced by an oblique impact? The excavation stage ends on release from shock and when the displacements by excavation cavity formation and downwards/sideward compression reach an end. What are the different kinds of craters? Mars, like the Earth, has seasons. must an impactor be to produce a given size impact structure? 12. 11. The Vredefort impact crater, about 100 kilometers (60 miles) from Johannesburg, South Africa, was formed just a little over 2 billion years ago. 19). 5. 13) hits the earth? Anthracite coal is generally shiny in appearance and breaks with a conchoidal fracture (broken glass also shows this type of fracture). These fragments or clasts can be very fine (ash) or coarse (lapilli) or very coarse (bombs and blocks). The force of the impacts create circular structures with raised rimmed wall; spatters of mud and smaller circular secondary craters may be seen (Fig. b. Justify your answer. Beware that even though an igneous rock may have a felsic composition (light color), the rock can contain dark colored minerals. But the environmental effects of impact crater formation go far beyond forming benign basins. In what direction did the water flow? i~4?7Z"UJmiCwbes%7Vo}bf_iK4Ev, u4J_8(Vjj#W]^`:*I23SPPEX
`p-1sU?"_F4I=?^i(.i]V These are not commonly tested for in an introductory lab. Shock waves behave like other waves: they can interfere and they may be reflected and refracted. Essentially, the Moon's surface has not been modified since early in its history, so most of its craters are still visible. Typically bowl-shaped craters. 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? The Chicxulub crater in the Yucatan peninsula, Mexico, is not visible at the surface of the seafloor. And again, one might suspect a process similar to rock tossed into mud. Find more similar flip PDFs like Planetary_Geology. 4. This can be easily confused with a crystal face and is the most difficult properties for students to master.ColorVisible light spectrum radiation reflected from a mineral.Look at the sample and determine its color - white, black, green, clear, etc.Crystal FormGeometric shape of a crystal or mineral.Examine and describe the geometric shape of the mineral - cubic, hexagonal, etc. Sometimes, impact structures are distinguished from impact craters by their weak morphological signature compared with a true crater. 11 0 obj
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The dark basins can be seen by the naked eye. . During the excavation phase, the massive shock wave causes the projectile to simultaneously melt and vaporize, spewing plumes of searing hot rock vapor miles high into the atmosphere. Although the resulting depression may bear some resemblance to the hole that results from throwing a pebble into a sandbox, the . 17. 3 0 obj
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The modification stage of impact cratering. The ejecta blanket has lobes, which may indicate wet material was ejected, suggesting that subsurface water or melted ice was mixed into the debris. The Moon does not. The GIF below shows the formation sequence of the model (a YouTube . Approximately 80% of Earth's surface is less than 200 million years old, while over 99% of the Moon's surface is more than 3 billion years old. The more mass it has the bigger the impact. e. Determine and record the diameter of Apollinaris Patera? When an impactor strikes the solid surface of a planet, a shock wave spreads out from the site of the impact. Spreading outwards from the point of contact, compressive shock waves are permanently reflected from the free target surface as tensile rarefaction waves of comparable intensities and, like the shock waves, are propagated downwards. Craters are the most common surface features on many solid planets and moonsMercury and our Moon are covered with craters. Around its base is a steep cliff as high as 6 km. And so far, the crater formation process has only lasted a few seconds. Fig. Large impact basins are also found on other planets, including Mars and Mercury. In impact research, the subdivision of the crater-forming process into three main stages has generally been accepted. This lab is an adaptation of an adaptation by Richard Harwood based upon the original NASA resource: A Teacher's Guide with Activities in Physical and Earth Sciences for Planetary Geology,: National Aeronautics and Space Administration, 1998, EG-1998-03-109, p. 238. Planetary_Geology was published by lavit shetty on 2021-11-18. A peak ring crater (Clearwater West, Canada, 32 km diameter). (Viking MDIM Volume 4)
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Students, staff, and faculty at Stony Brook University are hard at work gathering data on the history of Mars. Fortunately, these two aspects determine a mineral's physical properties. 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". Mercury and the Moon are covered with impact craters; their surfaces are very old. For the following, you will use the knowledge from previous questions to identify Martian landforms and describe the geologic processes that created them. Sedimentary rock identification is primarily based on composition. For the roughly 200 established terrestrial impact structures neither a comet nor a rubble pile asteroid could definitely be shown to have been the impactor. How can you tell? What is the diameter of the large crater towards the bottom of the image? stream
A geologic process. Coquina is composed almost entirely of shell or fossil fragments. The number of very large craters in the southern highlands implies a substantial age for the surface. Material Type: Lab; Class: Sci Thought/Processes I; Subject: Honors Program; University: George Mason University; Term: Unknown 1989; Fig. Mineral Physical Properties ChartPHYSICALPROPERTYDefinition*Testing MethodCleavageBreakage of a mineral along planes of weakness in the crystral structure.Examine the mineral for areas where the mineral is broken. 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. Are not commonly tested for in an introductory lab broken glass also shows this type of fracture.! Displacements by excavation cavity formation and downwards/sideward compression reach an end that the transient crater collapse in flip... 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