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The soil ecosystem
Published in Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz, Agroecology, 2023
Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz
As a whole, the layer of unconsolidated material between the soil surface and the solid bedrock of the earth below is called the regolith. The most basic element of the regolith is its mineral component, made up of soil particles formed from the breakdown of rocks or parent material. At any particular location, these soil particles may have been derived from the bedrock below, or they may have been transported from elsewhere. Where a soil’s mineral particles have been formed in place from the bedrock below, the soil is a residual soil. Where the mineral particles have been carried from some other location by wind, water, gravity, or ice, the soil is a transported soil.
Trees and Natural Fibers
Published in Antonio Paesano, Handbook of Sustainable Polymers for Additive Manufacturing, 2022
Prosina (2020) proposed algae as an ingenious approach for establishing long-term habitation on the Moon and Mars, by employing a printed mixture of regolith-filled algae to build habitable structures on those celestial bodies without resorting to mining and sifting. Regolith is a layer of loose, heterogeneous superficial deposits (dust, soil, broken rock, and likes) that covers solid rock on Earth, Moon, and Mars. The algae will be grown on-site in laboratory, and regolith will be harvested on-site. Algae present the following advantages: they lend themselves to be processed into TPs, can be converted into many everyday consumables including clothing, are rich in proteins, and can be transformed into food (dietary supplements and “superfoods”). The author discussed benefits, utilization, processing of algae, required infrastructure, and associated challenges.
Apollo in outline
Published in Jonathan Allday, Apollo in Perspective, 2019
On Earth, regolith is formed from the weathering of rocks. Physical weathering happens when water in the rocks freezes and expands to cause cracks. Chemical weathering comes about when rock minerals dissolve in water or acid. Biological weathering takes place when growing plant roots open up cracks in the rock. All of these are impossible on the Moon due to the lack of atmosphere, water and wind.
Quantifying weathering intensity using chemical proxies: a weathering index AFB
Published in Australian Journal of Earth Sciences, 2023
The overall thickness and zoned structure of the residual regolith are the result of the dynamic interplay of climatic and geological factors such as topography, drainage, tectonics, structure, and parent rock lithology (Elias, 2006). Although the order of vertical zones remains universal worldwide (Bardossy & Aleva, 1990), the number and thickness of specific zones, which is an expression of vertical gradient of the weathering intensity, can vary greatly from site to site. For example, for the ultramafic-hosted Ni laterite deposits, the most structured, clay silicate type profile mostly forms from clinopyroxene-bearing serpentinised peridotites under poor drainage conditions (Freyssinet et al., 2005; Gleeson et al., 2003). This low-gradient weathering profile typically consists of saprock, lower saprolite (Figure 8), which passes upwards into smectite-rich upper saprolite, transition/clay zone and limonite capped by hematitic duricrust.
Terrain-aware traverse planning for a Mars sample return rover
Published in Advanced Robotics, 2021
Other related research proposed to deploy a spectrometer to gather information used in path planning to update local terrain information. The first step is a mapping of geological units (hypothesis), and as the rover gains information about the terrain it can update its route using Bayesian inference [31]. However, a spectrometer is usually time consuming to deploy (about three hours [32]) and could be computationally demanding. A different instrument, easier to implement and deploy, could potentially alleviate this difficulty (e.g. cone penetrometer or shear vane [33]). Instruments have already been utilized to study the geotechnical properties of the regolith, as demonstrated by the Lunakhod rovers and the Apollo missions [34]. Experiments sent to the Moon to retrieve properties of the regolith [35] include a cone penetrometer (to measure bulk density and angle of internal friction [34]) and a cone vane penetrometer (a cone penetrometer with shear vanes) to take measurements of the bearing capacity of the Lunar soil [34]. Similar instruments to what was flown to the Moon have been proposed for future planetary missions to support extensive geotechnical studies [36], such as a percussive dynamic cone penetrometer [35], a low-velocity penetrometer [37] or a Geovane [33]. On Mars, the wheels of the Spirit and Opportunity rovers were used to derive cohesion and angle of internal friction of various soils in an attempt to gain more geotechnical knowledge of the Martian regolith [38].
Gold distribution and lithogeochemical discrimination of residual regolith and transported overburden, Minotaur gold deposit, Lake Lefroy, Western Australia
Published in Australian Journal of Earth Sciences, 2019
The residual regolith is divided into saprock, saprolite and plasmic zone (residual clay). The upper-most regolith units (typically found in a ‘complete’ regolith profile in the Yilgarn as noted by Anand & Paine, 2002), including a lateritic duricrust are not observed at Minotaur nor typically found in the Lake Lefroy region (Britt & Gray, 2007; Woolrich, 1994). Contacts are typically gradational, but generally display distinct colour and textural changes that mark the transition into different zones. The presence of a well-developed saprolite in some areas of the pit corresponds to the presence of shear zones, suggesting a role of structures in facilitating water movement and promoting chemical weathering. Other areas of the pit display comparatively less developed saprolite.