The characteristic layering or bedding of sedimentary rocks.
The formation of separate layers (of temperature, plant, or animal life) in a lake or reservoir. Each layer has similar characteristics such as all water in the layer has the same temperature.
The laying down of soil and other material over a period of time that allows the identification of the context of each find by archaeologists.
Process of or result of separating a sample into several subsamples according to specified criteria such as age groups, socio-economic status, etc. Last, 1988
stratified sample is one divided into a number of smaller samples. For example, in a survey covering a city, a stratified sample would divide the city into a number of smaller areas or strata (of known population) and sample a specific number of households in each stratum.
The behavior of having mineral sediments embedded in sedimentary rock.
Process in which units with similar characteristics are divided into groups called strata before the sampling process begins. Each unit is assigned to one and only one stratum based on prior knowledge about the unit. Separate samples are then selected within each stratum.
The layered structure of sedimentary rock.
1. Applied to rocks: the presence of layers, or strata; typical of sedimentary rock. 2. Applied to water: division of the water column into layers of different temperature or salinity.
This term is used to describe the arrangement of a body of water into two or more layers of different densities. Water expands, as it is heated (see Thermal Expansion); therefore hot water has a lower density than cooler water. In a storage water heater the less dense hot water "floats" above the cold water. This is a very stable arrangement and very little mixing can occur without mechanical agitation.
the arrangement of a body of water into two or more horizontal layers of differing characteristics (often temperature)
Characteristic of a system with socioeconomic strata, sharp social divisions based on unequal access to wealth and power; see stratum.
division of a forest, or any ecosystem, into separate layers of vegetation that provide distinct niches for wildlife. See canopy, understory, and herbaceous vegetation.
The separation of a fluid into two or more layers of uniform, but different densities. surface waves –A wave traveling on the interface between the air and water, visible to us as changes in the free surface elevation. thermocline –The simplest definition is the area of maximum temperature change (gradient) in the water column. This definition can fail however depending on the vertical resolution of the temperature profile (the distance between samples). A better definition is the area of maximum temperature change over a length scale suitable for the layer depths (e.g. in Cayuga Lake gradients over a meter rather then a millimeter).
(STRAT·i·fi·CA·tion). The successive or superimposed layers, either natural or the result of human activity, making up the surface of the earth.
A structure produced by deposition of sediments in beds or layers (strata), laminae, lenses, wedges, and other essentially tabular units.
The formation, accumulation, or deposition of materials in layers, such as layers of fresh water overlying higher salinity water (salt water) in estuaries.
the separation of water masses into layers. Stratification keeps layers of water from mixing together and hinders the transport of dissolved gases and chemicals from one layer to another.
the act or process or arranging persons into classes or social strata
the condition of being arranged in social strata or classes within a group
forming or depositing in layers
layeres according to density; applies to fluids. Stable stratification occurs when density decreases continuously (but not necessarily uniformly) with distance fromt the Earth's center
The construction of a random sample, for practical purposes, by identifying groups within the population that tend to be relatively uniform and including strata, or groups, of the sample in numbers that proportionally represent their membership in the entire population.
The arrangement of sedimentary rocks in strata; bedding. It may be indicated by differences in texture, cementation, color, or composition.
This enables the water entering the storage tank to flow directly into the tank layer of the corresponding temperature.
the layers of civilization at a once-inhabited site discovered by archaeologists; numerous cities in the ancient Middle East were continually built on top of destroyed cities
Horizontal layering of water in a lake caused by temperature-related differences in density. A thermally stratified lake is generally divided into the epilimnion (uppermost, warm, mixed layer), metalimnion (middle layer of rapid change in temperature and density) and hypolimnion (lowest, cool, least mixed layer).
A structure produced with shaking tables by deposition of feed ores forming beds or layers with the action of water.
Pertaining to the formation of layers.
A sampling technique in which sampling is done separately for separate parts of the population. Stratification is often used to ensure that one has an adequate number of sampling units with relatively rare characteristics (e.g., stratification may be done on race/ethnic status if one wishes to make comparisons among racial/ethnic groups).
Physical layering of the water column resulting from density differences caused by salinity or temperature variation.
The division of the audience into sub-groups, called strata, by criteria such as company size, job junction, industry sector, etc.
when the water in a dam or weir pool forms layers that do not readily mix with each other.
the tendency of competing trees and shrubs in a developing stand to separate into different layers. The stratification of a stand can provide distinct niches for wildlife. See canopy, understory, and herbaceous vegetation.
In benthos, the presence of different infaunal species at distinct respective horizons below the sediment-water interface.
The division of the population into sub-populations, which are then sampled independently.
The condition where a fluid appears in layers.
A layered structure of sedimentary rocks in which the individual layers can be traced a considerable distance. The layers can be caused by many differences which include materials of different composition, color, grain size or orientation.
separation of a study cohort into subgroups or strata according to specific characteristics such as age, gender, etc., so that these differences which might affect the outcome of the study, can be taken into account.
The division of water in lakes and ponds into layers with different temperatures and oxygen content. Oxygen content declines with depth, while the uppermost layer is warmest in summer and coolest in winter.
(a) The operation of storing seeds in, and often in alternate layers with a moist medium such as sand or peat, in order to maintain viability or overcome dormancy Ecol.). The disposition of vegetation in superposed storeys Stat.). Subdivision of a population into strata or blocks or sampling unit as a preliminary to sampling. Each stratum should be more homogeneous in respect of the variable being measured than the population as a whole. ( BCFT.).
(lake) - (3) in a lake, the presence of two or more horizontal layers of water of differing characteristics, such as density.
A system which structures unequal access of the society's members to opportunities, wealth, power. Caste and class are two ways societies can be stratified. In addition to class in our own society, gender and ethnicity are important means of stratification.
Layering (see hypolimnion, metalimnion, or epilimnion).
characters of sedimentary rocks being a succession of horizontal or inclined stratas.
Distinct layers of water in a dam or weir pool, formed when there is little movement to cause intermixing-usually in summer when deeper layers of water become cold and deoxygenated. These changes may, in turn, induce other water quality changes.
A physical and chemical process that results in the formation of distinct layers of water within a lake or reservoir (i.e., epilimnion, metalimnion, and hypolimnion).
The separation of a sample population into non-overlapping groups based on a habitat or population characteristic that can be divided into multiple levels. Groups are homogeneous within, but distinct from, other strata.
The layering of water due to differences in density. Water's greatest density occurs at 39 Deg.F (4 Deg.C). As water warms during the summer, it remains near the surface while colder water remains near the bottom. Wind mixing determines the thickness of the warm surface water layer (epilimnion), which usually extends to a depth of about 20 feet. The narrow transition zone between the epilimnion and cold bottom water (hypolimnion) is called the metalimnion or thermocline.
With time, the liquid portion of a battery (the electrolyte) will separate into layers. The sulfuric acid will go to the bottom, and the water to the top. If allowed to sit in this condition the battery will be ruined. Equalization will bubble and mix the electrolyte eliminating this problem.
Layers of deposits that provide archaeologists with one of the major tools or clues for interpreting archaeological sites (stratigraphy). Over time, debris and soil accumulate in layers. Color, texture, and contents may change with each layer. Archaeologists try to explain how each layer was added--if it occurred naturally, deliberately (garbage), or from the collapse of structures--and they record it in detailed drawings so others can follow.
The layered arrangement of sediments, sedimentary rocks, or extrusive igneous rocks.
The existence or formation of distinct layers or laminae in a body of water identified by differences in thermal or salinity characteristics (e.g., densities) or by oxygen or nutrient content.
refers to the layering of material; examples include the layering of sediments; and the layering of freshwater over saltwater.
the formation of strata; deposition or recurrence in strata; bedding. [AHDOS
In archaeology, especially in the course of excavation, stratification is a paramount and base concept. It is largely based on the Law of Superposition. When archaeological finds are below the surface of the ground (as is most commonly the case), the identification of the context of each find is vital to enable the archaeologist to draw conclusions about the site and the nature and date of its occupation.
