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- Partially reduced plant or wood
material, containing approximately 60 percent carbon and 30 percent oxygen. An
intermediate material in process of coal formation.
Source: Leet, L. Don. 1982.
Physical Geology, 6th Edition. Englewood Cliffs, NJ: Prentice-Hall
- There are two types of peat, low moor (Flachmoor) and high moor (Hochmoor)
peat. Low moor peat is the most common starting material in coal genesis.
It therefore constitutes a caustobiolith of low diagenetic degree. Peat is
formed in marshes and swamps from the dead, and partly decomposed remains
of the marsh vegetation. Stagnant ground water is necessary for peat
formation to protect the residual plant material from decay. Peat has a
yellowish brown to brownish black color, is generally of the fibrous
consistency, and can be either plastic or friable; in its natural state it
can be cut; further, it has a very high moisture content (above 75%,
generally above 90%). It can be distinguished from brown coal by the fact
that the greater part of its moisture content can be squeezed out by
pressure (e.g., in the hand). Peat also contains more plant material in a
reasonably good state of preservation than brown coal. Individual plant
elements, such as roots, stems, leaves, and seeds, can commonly be seen in
it with the unaided eye. Failing that, treatment of peat with dilute
alkali will make visible many of these plant tissues. Further, peat is
richer in cellulose than brown coal (reaction with Fehling's solution).
Unlike brown coal, peat still contains cellulose, protected by lignin or
cutin, which gives a reaction with chlorzinc iodide. Correspondingly, peat
shows under the microscope tissues that have not undergone either
lignification, suberinization, or cutinization; this is not the case in
brown coal. The reflectance of peat is low (about 0.3%). Microscopic
examination is best undertaken with transmitted light. IHCP
Source:
Dictionary of Mining, Mineral, and Related Terms
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