Examinando por Autor "Garvin, J. B."

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Extraformational sediment recycling on Mars
(Geo Science World, 2020-10-06) Edgett, K. S.; Branham, S. G.; Bennett, A.; Edgard, L. A.; Edwards, C. S.; Fairén, A.; Fedo, C. M.; Fey, D. M.; Garvin, J. B.; Grotzinger, J. P.; Gupta, S.; Henderson, M. J.; House, C. H.; Mangold, N.; McLennan, S. M.; Newsom, H. E.; Rowland, S. K.; Siebach, K. L.; Thompson, L.; Van Bommel, S. J.; Wiens, R. C.; Williams, R. M. E.; Yingst, R. A.; European Research Council (ERC); 0000-0003-1206-1639; 0000-0001-6415-1332; 0000-0001-7197-5751; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Extraformational sediment recycling (old sedimentary rock to new sedimentary rock) is a fundamental aspect of Earth’s geological record; tectonism exposes sedimentary rock, whereupon it is weathered and eroded to form new sediment that later becomes lithified. On Mars, tectonism has been minor, but two decades of orbiter instrument–based studies show that some sedimentary rocks previously buried to depths of kilometers have been exposed, by erosion, at the surface. Four locations in Gale crater, explored using the National Aeronautics and Space Administration’s Curiosity rover, exhibit sedimentary lithoclasts in sedimentary rock: At Marias Pass, they are mudstone fragments in sandstone derived from strata below an erosional unconformity; at Bimbe, they are pebble-sized sandstone and, possibly, laminated, intraclast-bearing, chemical (calcium sulfate) sediment fragments in conglomerates; at Cooperstown, they are pebble-sized fragments of sandstone within coarse sandstone; at Dingo Gap, they are cobble-sized, stratified sandstone fragments in conglomerate derived from an immediately underlying sandstone. Mars orbiter images show lithified sediment fans at the termini of canyons that incise sedimentary rock in Gale crater; these, too, consist of recycled, extraformational sediment. The recycled sediments in Gale crater are compositionally immature, indicating the dominance of physical weathering processes during the second known cycle. The observations at Marias Pass indicate that sediment eroded and removed from craters such as Gale crater during the Martian Hesperian Period could have been recycled to form new rock elsewhere. Our results permit prediction that lithified deltaic sediments at the Perseverance (landing in 2021) and Rosalind Franklin (landing in 2023) rover field sites could contain extraformational recycled sediment.
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Initial results from the InSight mission on Mars
(Nature Research Journals, 2020-02-24) Banerdt, W. B.; Smrekar, S.; Banfield, D.; Giardini, D.; Golombek, M.; Johnson, C. L.; Lognonné, P.; Spiga, A.; Spohn, T.; Perrin, C.; Stähler, S.; Antonangeli, D.; Asmar, S.; Beghein, C.; Bowles, N.; Bozdag, E.; Chi, P.; Christensesn, U.; Clinton, J.; Collins, G. S.; Daubar, I.; Dehant, V.; Drilleau, M.; Fillingim, M.; Folkner, W.; García, R. F.; Garvin, J. B.; Grant, J.; Grott, M.; Grygorczuk, J.; Hudson, T.; Irving, J. C. E.; Kargl, G.; Kawamura, T.; Kedar, S.; King, S.; Knapmeyer Endrun, B.; Knapmeyer, M.; Lemmon, M. T.; Lorenz, R.; Maki, Justin N.; Margerin, L.; McLennan, S. M.; Michaut, C.; Mimoun, D.; Mittelholz, A.; Mocquet, A.; Morgan, P.; Mueller, N. T.; Murdoch, N.; Nagihara, S.; Newman, C. E.; Nimmo, F.; Panning, M.; Thomas Pike, W.; Plesa, A. C.; Rodríguez, Sébastien; Rodríguez Manfredi, J. A.; Russell, C. T.; Chmerr, N.; Siegler, M.; Stanley, S.; Stutzmann, E.; Teanby, N.; Tromp, J.; Van Driel, M.; Warner, N.; Weber, R.; Wieczorek, Mark A.; Agence Nationale de la Recherche (ANR); Swiss National Science Foundation (SNSF); Tromp, J. [0000-0002-2742-8299]; Rodríguez, S. [0000-0003-1219-0641]; Lognonné, P. [0000-0002-1014-920X]; Perrin, C. [0000-0002-7200-5682]; Murdoch, N. [0000-0002-9701-4075]; Knapmeyer, M. [0000-0003-0319-2514]; Rodríguez Manfredi, J. A. [0000-0003-0461-9815]; Spiga, A. [0000-0002-6776-6268]; Panning, M. P. [0000-0002-2041-3190]; García, R. [0000-0003-1460-6663]; Johnson, C. [0000-0001-6084-0149]; Stutzmann, E. [0000-0002-4348-7475]; Knapmeyer-Endrun, B. [0000-0003-3309-6785]; Schmerr, N. [0000-0002-3256-1262]; Irving, J. C. E. [0000-0002-0866-8246]; Morgan, P. [0000-0001-8714-4178]; Mueller, N. [0000-0001-9229-8921]; Pike, W. [0000-0002-7660-6231]; Kawamura, T. [0000-0001-5246-5561]; Clinton, J. [0000-0001-8626-2703]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
NASA’s InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) mission landed in Elysium Planitia on Mars on 26 November 2018. It aims to determine the interior structure, composition and thermal state of Mars, as well as constrain present-day seismicity and impact cratering rates. Such information is key to understanding the differentiation and subsequent thermal evolution of Mars, and thus the forces that shape the planet’s surface geology and volatile processes. Here we report an overview of the first ten months of geophysical observations by InSight. As of 30 September 2019, 174 seismic events have been recorded by the lander’s seismometer, including over 20 events of moment magnitude Mw = 3–4. The detections thus far are consistent with tectonic origins, with no impact-induced seismicity yet observed, and indicate a seismically active planet. An assessment of these detections suggests that the frequency of global seismic events below approximately Mw = 3 is similar to that of terrestrial intraplate seismic activity, but there are fewer larger quakes; no quakes exceeding Mw = 4 have been observed. The lander’s other instruments—two cameras, atmospheric pressure, temperature and wind sensors, a magnetometer and a radiometer—have yielded much more than the intended supporting data for seismometer noise characterization: magnetic field measurements indicate a local magnetic field that is ten-times stronger than orbital estimates and meteorological measurements reveal a more dynamic atmosphere than expected, hosting baroclinic and gravity waves and convective vortices. With the mission due to last for an entire Martian year or longer, these results will be built on by further measurements by the InSight lander.