8 research outputs found

    The Multi-Stage History of Mt. Sharp

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    The Curiosity rover is exploring Gale crater and Mt. Sharp, Gale's 5km high central mound. We are investigating the history of alteration and erosion of Mt. Sharp using orbital imagery, spectroscopy and rover observations. Our results suggest a significant time gap between emplacement of the upper and lower sections of the mound. Crater counts show that the lower mound was formed soon after Gale itself, and that it contains distinct units ranging in altitude from approximately 4,500 to 1,800 m. Spectral data suggest that many units contain phyllosilicates. We found that these claybearing rocks occur in distinct layers concentrated below 2,900 m. Parts of the lower mound exhibit a transition from clays to sulfates with increasing altitude. The lower mound shows evidence of flowing water, including canyons and inverted channels. Wind erosion produced kmscale yardangs and scalloped cliffs. Our mapping shows that many yardangs in the lower mound are claybearing, with a predominant orientation of around NS. Curiosity's groundlevel images show myriad finescale, mainly horizontal layers in the lower mound. The rover has found stream beds and conglomerates, indicating that water once flowed on the crater floor. Drilling near the deepest point in Gale produced abundant clay, providing additional evidence of aqueous alteration. Upper mound units range in altitude from 2,100 m to +500 m, and mantle the lower mound above an angular unconformity. Most upper mound units are composed of layers. The formation age of the upper mound is unknown, since few craters are preserved. Claybearing layers are detectable in several locations, mainly at altitudes near 2,000 m. There is no evidence of water flow, but wind erosion has scalloped the surfaces and edges of layers, and finescale yardangs are common. Correlations between yardangs and clay spectra are apparent only in the lowermost units of the upper mound. Yardang orientations vary, and include NS, NWSE, and NESW. Upper mound units resemble the planetwide Medusae Fossae formation, dated as Hesperian and argued to be composed of ignimbrites. Medusae Fossae layers are easily eroded by wind, and our mapping demonstrates their resemblance to upper mound finescale yardangs. The history of Mt. Sharp started with deposition and lithification of sediments shortly after crater formation. Some lower mound layers were partially altered to clays and sulfates, and water formed streams and canyons. Wind erosion of the lower mound produced largescale yardangs, particularly in clayrich layers, oriented generally NS. Upper mound units were emplaced following a considerable period of wind erosion. The absence of water flow on the upper mound suggests that these units were emplaced after atmospheric loss rendered water unstable at the surface. The shift in dominant wind direction, as indicated by yardang orientations, also argues for a time gap between erosion of the lower and upper mound. These observations are consistent with upper mound units being related to the Hesperian Medusae Fossae formation. During 2014 Curiosity is expected to reach the foot of Mt. Sharp and ascend through the clayrich layers, into the sulfaterich layers, and possibly past the interface with the upper mound. This will be a unique opportunity to field check geologic models on the surface of Mars

    The Gale Crater Mound in a Regional Geologic Setting: Comparison Study of Wind Erosion in Gale Crater and Within a 1000 KM Radius

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    Gale is a Late Noachian/Early Hesperian impact crater located on the dichotomy boundary separating the southern highlands and the northern lowlands of Mars. NASA's Curiosity Rover is currently exploring Gale, searching for evidence of habitability early in Mars history. With an approximate diameter of 155 km, and a approx. 5 km central mound informally titled Mt. Sharp, Gale represents a region of geologic interest due to the abundance of knowledge that can be derived, through its sedimentary deposits, pertaining to the environmental evolution of Mars. This study was undertaken to compare wind erosional features in Gale Crater and within sediments in a 1000 km radial area. The ultimate objective of this comparison was to determine if or how Gale relates to the surrounding region

    The Formation and Erosion History of Mt. Sharp

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    The Curiosity rover is exploring 155 km diameter Gale crater and Mt. Sharp, Gale's 5 km high central mound (Fig. 1). This study addresses the formation and erosion history of Mt. Sharp. Gale lies on the topographic dichotomy between the southern highlands and the northern plains - a drop of over 2 km [1,2]. Altitude differences between the north and south rim reflect this regional slope, as do altitude differences between the deep annulus north of Mt. Sharp and the southern crater floor. Orbiter and rover images demonstrate that most exposed areas on Mt. Sharp consist of thin, sub-parallel units interpreted as sedimentary layers [3]. Gale is typical of the 50 large martian craters that have been totally or partially filled with such layers [4,5]. In many craters these sediments have been deeply eroded. Central Peak and Peak Ring: The highest point on Mt. Sharp, near the crater's center, is interpreted as a central peak [6]. The peak has a massive lower portion and a thin, smooth capping deposit (Fig. 2). Gale's size is transitional between martian craters with single central peaks and craters with peak rings approximately half the crater's diameter [2,6]. The boundaries of Mt. Sharp, as well as an arc of hills to the southeast of the mountain, closely match a circle approximately 80 km in diameter (Fig. 3). This morphology suggests that the Gale impact may have formed both a central peak and a partial peak ring, which is covered by the sediments of Mt. Sharp in the north and possibly exposed in the arc of eroded hills in the southeast quadrant (Figs. 3,4)

    The Complex, Multi-Stage History of Mt. Sharp

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    The Curiosity rover is exploring 155 km diameter Gale crater and Mt. Sharp, Gale's 5 km high central mound. This study addresses the formation and erosion history of Mt. Shar

    Exploring the experiences of being an ethnic minority student within undergraduate nurse education: A qualitative study

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    © 2019 The Author(s). Background: Students studying in a country where another language is spoken face multiple challenges including their ability to fully integrate with peers and academic pressures in trying to obtain an undergraduate nursing degree. The aim of the study was to explore the lived experiences of students, from varying cultural and ethnic backgrounds, undertaking an undergraduate nursing degree. Methods: The study adopted a qualitative design and eight individual semi-structured interviews were conducted. The interviews were analysed using manifest content analysis according to Graneheim and Lundman. Results: Students reported feelings of isolation and the lack of opportunities to integrate with native students within academia and practice. The need for personal support was a crucial factor that was independent of gender and students reported challenges related to both language and culture during the programme. Conclusions: Suggestions arising from this study includes appropriate support systems within academia and practice. It is imperative that universities and practice settings promote and integrate cultural awareness within academia and practice in meeting the needs of students and providing culturally appropriate nursing care, thereby providing opportunities for all students to become competent and professional practitioners

    Chemistry, Physical Chemistry, and Uses of Molecular Fluorocarbon−Hydrocarbon Diblocks, Triblocks, and Related Compounds—Unique “Apolar” Components for Self-Assembled Colloid and Interface Engineering

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