A. L. Dial Jr.
M.E. Strobell
Harold Masursky
1978
<p><span class="TextRun SCXW190149089 BCX8" lang="EN-US" xml:lang="EN-US" data-contrast="auto"><span class="NormalTextRun SCXW190149089 BCX8">The </span><span class="NormalTextRun SCXW190149089 BCX8">Phoenicis</span> <span class="NormalTextRun SCXW190149089 BCX8">Lacus</span><span class="NormalTextRun SCXW190149089 BCX8"> quadrangle (named Lake of the </span><span class="NormalTextRun SCXW190149089 BCX8">Pheonix</span><span class="NormalTextRun SCXW190149089 BCX8"> by Schiaparelli, 1</span><span class="NormalTextRun SCXW190149089 BCX8">877) includes some of the largest geologic features recognized on the terrestrial planets. </span><span class="NormalTextRun SCXW190149089 BCX8">Arsia</span><span class="NormalTextRun SCXW190149089 BCX8"> and Pavonis Montes, (“South Spot” and “Middle Spot”</span><span class="NormalTextRun SCXW190149089 BCX8"> of Mariner 9) rise 18 and 17 km, respectively, above the surrounding plateau</span><span class="NormalTextRun SCXW190149089 BCX8"> to an elevation of about 27 km above the 6.1 millibar base level. These mountains and </span><span class="NormalTextRun SCXW190149089 BCX8">the </span><span class="NormalTextRun SCXW190149089 BCX8">two large volcanoes </span><span class="NormalTextRun SCXW190149089 BCX8">Ascraeus</span><span class="NormalTextRun SCXW190149089 BCX8"> and Olympus Montes, located outside the quadrangle to the north, are also about 27 km in height</span><span class="NormalTextRun SCXW190149089 BCX8">,</span><span class="NormalTextRun SCXW190149089 BCX8"> about three times as high as any </span><span class="NormalTextRun SCXW190149089 BCX8">volcano on Earth. </span><span class="NormalTextRun SCXW190149089 BCX8">The summit caldera</span><span class="NormalTextRun SCXW190149089 BCX8"> of </span><span class="NormalTextRun SCXW190149089 BCX8">Arsia</span><span class="NormalTextRun SCXW190149089 BCX8"> Mons. </span><span class="NormalTextRun SCXW190149089 BCX8">m</span><span class="NormalTextRun SCXW190149089 BCX8">ore than 100 km in diameter, is the largest known. Syria and Sinai Plana are part of </span><span class="NormalTextRun SCXW190149089 BCX8">t</span><span class="NormalTextRun SCXW190149089 BCX8">he highest plat</span><span class="NormalTextRun SCXW190149089 BCX8">eau on Mars, the </span><span class="NormalTextRun SCXW190149089 BCX8">Tharsis</span><span class="NormalTextRun SCXW190149089 BCX8"> plateau; their relative elevation, 10 km</span><span class="NormalTextRun SCXW190149089 BCX8">, is twice that of the Tibetan Plateau, the highest plateau on Earth</span><span class="NormalTextRun SCXW190149089 BCX8">. Noctis </span><span class="SpellingError SCXW190149089 BCX8">Labyrinthus</span><span class="NormalTextRun SCXW190149089 BCX8">, the great system of </span><span class="NormalTextRun SCXW190149089 BCX8">fault</span><span class="NormalTextRun SCXW190149089 BCX8"> valleys</span><span class="NormalTextRun SCXW190149089 BCX8"> at the we</span><span class="NormalTextRun SCXW190149089 BCX8">st</span><span class="NormalTextRun SCXW190149089 BCX8"> end of </span><span class="NormalTextRun SCXW190149089 BCX8">Valles</span> <span class="SpellingError SCXW190149089 BCX8">Marineris</span><span class="NormalTextRun SCXW190149089 BCX8"> which is located </span><span class="NormalTextRun SCXW190149089 BCX8">o</span><span class="NormalTextRun SCXW190149089 BCX8">u</span><span class="NormalTextRun SCXW190149089 BCX8">tside the quadrangle to the east, displays a more clearly developed system of faults tha</span><span class="NormalTextRun SCXW190149089 BCX8">n</span><span class="NormalTextRun SCXW190149089 BCX8"> the largest continental fault system on Earth, the East African</span><span class="NormalTextRun SCXW190149089 BCX8"> rift valleys. The land slopes down to the northwest into </span><span class="NormalTextRun SCXW190149089 BCX8">Amazonis</span><span class="NormalTextRun SCXW190149089 BCX8"> Planitia</span><span class="NormalTextRun SCXW190149089 BCX8"> (fig. 1); the difference in elevation between </span><span class="NormalTextRun SCXW190149089 BCX8">the volcanic peaks and </span><span class="NormalTextRun SCXW190149089 BCX8">Amazonis</span><span class="NormalTextRun SCXW190149089 BCX8"> low plains is greater than the relief form the top of the Andes to the bottom of the Peruvian trench. Th</span><span class="NormalTextRun SCXW190149089 BCX8">is great</span><span class="NormalTextRun SCXW190149089 BCX8"> slope on Mars is </span><span class="AdvancedProofingIssue SCXW190149089 BCX8">similar to</span><span class="NormalTextRun SCXW190149089 BCX8"> the continental shelf and slope that marks the transition bet</span><span class="NormalTextRun SCXW190149089 BCX8">ween</span><span class="NormalTextRun SCXW190149089 BCX8"> the continents and ocean basin floors of the Ear</span><span class="NormalTextRun SCXW190149089 BCX8">th.</span></span><span class="EOP SCXW190149089 BCX8" data-ccp-props="{"201341983":0,"335559739":160,"335559740":259}"> </span></p>
application/pdf
10.3133/i896
en
U.S. Geological Survey
Geologic map of the Phoenicis Lacus Quadrangle of Mars
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