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Stonelayer
A stonelayer, or soil stonelayer, or stone line, is a three-dimensional subsurface layer, or soil horizon, dominated by coarse particles (>2mm), that generally follows (mimics) the surface topography (Sharpe 1938). A stonelayer occupies the basal horizon of two-layered soil biomantles (Paton et al. 1995; Schaetzl and Anderson 2005; Fey 2009; Wilkinson et al. 2009). A stonelayer may be one stone thick, and thus appear in a trench or pit as a "stone line," or it may be several stones thick and appear as a "stone zone" (Johnson 1989). The gravel components of stonelayers may be compositionally variable, and while many are lithic clasts, often of quartzose composition, others may be metallic nodules and concretions of iron and manganese oxides, human artifacts, snail and clam shells (in highly calcareous soils), precious and semi-precious stones, or some combination thereof (Aleva 1983, 1987; Johnson 2002). History Few topics in the annals of Earth science have generated more controver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Biomantle
The soil biomantle can be described and defined in several ways. Most simply, the soil biomantle is the organic-rich bioturbated upper part of the soil, including the topsoil where most biota live, reproduce, die, and become assimilated. The biomantle is thus the upper zone of soil that is predominantly a product of organic activity and the area where bioturbation is a dominant process. Soil bioturbation consists predominantly of three subsets: ''faunalturbation'' (animal burrowings), ''floralturbation'' (root growth, tree-uprootings), and ''fungiturbation'' (mycelia growth). All three processes promote soil parent material destratification, mixing, and often particle size sorting, leading with other processes to the formation of soil and its horizons. While the general term bioturbation refers mainly to these three mixing processes, unless otherwise specified it is commonly used as a synonym to faunalturbation (animal burrowings). One- and two-layered biomantles, soil stonelayers ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Horizon
A soil horizon is a layer parallel to the soil surface whose physical, chemical and biological characteristics differ from the layers above and beneath. Horizons are defined in many cases by obvious physical features, mainly colour and texture. These may be described both in absolute terms (particle size distribution for texture, for instance) and in terms relative to the surrounding material, i.e. 'coarser' or 'sandier' than the horizons above and below. The identified horizons are indicated with symbols, which are mostly used in a hierarchical way. Master horizons (main horizons) are indicated by capital letters. Suffixes, in form of lowercase letters and figures, further differentiate the master horizons. There are many different systems of horizon symbols in the world. No one system is more correct—as artificial constructs, their utility lies in their ability to accurately describe local conditions in a consistent manner. Due to the different definitions of the horizon symb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former term specifically to displaced soil. Soil consists of a solid phase of minerals and organic matter (the soil matrix), as well as a porous phase that holds gases (the soil atmosphere) and water (the soil solution). Accordingly, soil is a three-state system of solids, liquids, and gases. Soil is a product of several factors: the influence of climate, relief (elevation, orientation, and slope of terrain), organisms, and the soil's parent materials (original minerals) interacting over time. It continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness, soil ecologists regard soil as an ecosystem. Most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stone Line
A stone line (see also Stonelayer) is a three-dimensional subsurface layer, or ‘carpet,’ of stones evident as a ‘line of stones’ in natural exposures such as soils, road cuts, and trenches. Stone lines that are more than one stone thick have been called ‘stone zones’. Stone lines and stone zones are known to occur in soils, paleosols (buried soils), and in non-soil geologic-stratigraphic sequences. Where present in stratigraphic sequences, if the units were deposited by running water, the stones are usually imbricated (individual stones are lapped, or leaning, upon one another in the direction of water flow). This is strong evidence that such stone lines are geogenic. On the other hand, a stone line that is present in a soil or a paleosol is invariable non-imbricated and follows (mimics) the surface topography of the soil, or the paleosurface of a paleosol. This is strong evidence that such stone lines are pedogenic, and produced by soil forming processes. As it turns out ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil [[Soil Biomantle
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former term specifically to displaced soil. Soil consists of a solid phase of minerals and organic matter (the soil matrix), as well as a porous phase that holds gases (the soil atmosphere) and water (the soil solution). Accordingly, soil is a three-state system of solids, liquids, and gases. Soil is a product of several factors: the influence of climate, relief (elevation, orientation, and slope of terrain), organisms, and the soil's parent materials (original minerals) interacting over time. It continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness, soil ecologists regard soil as an ecosystem. Most so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marker Horizon
Marker horizons (also referred to as chronohorizons, key beds or marker beds) are stratigraphic units of the same age and of such distinctive composition and appearance, that, despite their presence in separate geographic locations, there is no doubt about their being of equivalent age (isochronous) and of common origin. Such clear markers facilitate the correlation of strata, and used in conjunction with fossil floral and faunal assemblages and paleomagnetism, permit the mapping of land masses and bodies of water throughout the history of the earth. They usually consist of a relatively thin layer of sedimentary rock that is readily recognized on the basis of either its distinct physical characteristics or fossil content and can be mapped over a very large geographic area.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, J.A., eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. As a result, a key bed is useful for correlati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
