Coal formation is a very controversial issue in the creation vs. evolution argument, and one that has been under debate for many years. Secular (or uniformitarian) geologists traditionally teach that coal is formed at the bottom of swamps over millions of years of uniform peat deposition. This theory, known as the autochthonous theory states that coal is formed by slow peat accumulation, and suggests that the vegetation grew in place in the swamps or bogs. In contrast, most creation geologists hold to the allochthonous theory, and argue that coal can form quickly when put into the proper environment. This theory states that the required vegetation was placed rapidly by flood conditions. 
The process of coal formation is typically broken down into 4 stages.
The first is the production of peat. Normally, plant matter that ends up in water will break down due to the presence of oxygen and carbon dioxide. However, when oxygen is not present, the material only partially breaks down. Whatever is left from this process is called peat. Peat has a soft, spongy texture. This peat must be dried before it can be individually burned for heat or energy; therefore it is not used for this purpose very often.
The second stage of the process is the formation of lignite. Lignite is formed when peat is put under a substantial amount of vertical pressure, such as the accumulation of sediments. This form of coal is generally only used if no other source of fuel is available.
Bituminous coal or soft coal is the third stage in formation. This type results from continued pressure. The primary difference between this type and the other two is that this is the first form in which no plant material remains. Bituminous coal is used greatly in industries as fuel.
Anthracite or hard coal is the final stage in coal formation. This type of coal has the texture of a rock and has some luster. This type results from high temperature and pressure. It burns with a small flame and with little smoke. 
Creation scientists has suggested new ways for coal to form. Evidence is beginning to show that temperature and pressure may not be as important to coal formation as was previously assumed.
The eruption at Mount St. Helens destroyed the surrounding forested and resulted in huge numbers of tree floating in the nearby Spirit Lake. These trees have been stagnant in Spirit Lake for the past 30 years. The abrasive forces from the wind and waves have removed the branches and bark from the trees. Scuba investigations have shown that a fairly thick layer of peat has formed on the floor of the lake. The same peat that evolutionary scientists claim take about 1000 years to form one inch formed within 30 years. This peat is very similar to other peat deposits in the Eastern United States. All that is required is that this peat be covered and heated and it will form into coal. This formation proves that not only can coal form quickly, it can also form in areas outside of swamps like the evolutionists claim.
Upon the eruption of Mt.St Helens, ash was blown into the air and began to accumulate in the lakes surrounding the area. Volcanic ash is very rich in carbon. As the trees that filled Spirit Lake sank to the bottom, ash continually washed over them. This combination of ash and trees has generated a peat bed very similar to many of the coal beds we find around the world. This compelling discovery suggests that the majority of our modern coal beds could have been formed through a combination of pyroclastic volcanic eruptions, erosion, flooding, and deposition. All of these factors would have come as a result of Noah's flood.
Fossils in Coal
Some of the most important evidence against the autochthonous theory is not how the coal forms, but what we find in it. It is very common to find plant fossils inside coal deposits. While many of these plants do have the ability to thrive in swampy climates, according to their anatomy, they prefer well drained soil. It also has been found that swamps have a greater accumulation of peat in cooler climates. Swamps that are exposed to the sun have smaller peat deposits due to evaporation. 
Another interesting thing about the fossils found in coal deposits is that we find marine fossils in coal. These marine fossils being found along with non marine plants suggests that the two were mixed during transport. An example of this is the small marine tubeworm Spirorbis. This worm is often time found attached to Carboniferous coals of Europe and North America. 
Dr. Andrew Snelling and John Mackay have done much research on the rapid formation of coal. Most of their work focuses on the use of the Newcastle coals as an analog for the formation of diluvian coal. The coal seams of interest were the Upper and Lower Pilot. They provide evidence that the trees ,that were later transformed into coal, found there were deposited quickly via deposited ash and mud flows. They then note that "the logs and coal seams at Swansea Heads and Quarries Head in the Newcastle area, and the Awaba marker bed above them are more readily and consistently explained by invoking a rapid and catastrophic allochthonous origin using the Mount St. Helens event as a model, rather than the buried peat swamp hypothesis."
Whitcomb and Morris on subject
- Coal is the end product of the metamorphism of tremendous quantities of plant remains under the action of temperature, pressure and time. Coal has been found throughout the geologic column and in all parts of the world, even in Antarctica. Many coal fields contain great numbers of coal-bearing strata, interbedded with strata of other materials, each coal seam having a thickness which may vary from a few inches to several feet. And each foot of coal must represent many feet—just how many, no one knows—of plant remains, so that the coal measures testify of the former existence of almost unimaginably massive accumulations of buried plants.
- Coal geologists have long been divided into two camps, those favoring the autochthonous (growth-in-place) theory of coal origin and those favoring the allochthonous (transportation and deposition) theory [which is consistent with the Noahic Flood]. Consistent uniformitarianism, of course, tends to favor the former and attempts to picture the coal-forming [growth in place theory] process in terms of modern peat deposits forming under swamplands, such as in the Dismal Swamp of Virginia. The great thickness of the coal beds is accounted for on this theory by assuming a continuous subsidence [= a subsiding: a sinking of vegetation to the 'bottom'] of the land more or less keeping up with the slow accumulation of plant remains. The interbedded strata of non-carbonaceous deposits [= inorganic material] are [again] explained by [assuming] alternating marine transgressions [i.e., periodic local flooding] and resulting periods of sediment deposition. A wide variety of types of these intervening sediments have been noted and attempts made to explain them in terms of 'cyclothems' or recurring cycles of deposition of different kinds of materials corresponding to the different stages of marine transgression and regression...
- If the autochthonous theory of coal bed is correct, it is testimony to quite a marvelous sequence of circumstances. One or two or three coal seams formed by alternate stages of swamp growth, peat accumulation, marine transgression and emergence, etc., might be believable, but the assertion that this cycle was repeated scores of times in the same spot, over a period of perhaps millions of years, is not so easy to accept...
- This theory, which is purportedly uniformitarian in essence, is actually anything but that, as there is no modern parallel for any of its major features. The peat-bog theory constitutes a very weak attempt to identify a modern parallel, but it will hardly suffice...
- ...there is no actual evidence that peat is now being transformed into coal anywhere in the world...
- As a matter of fact, except for uniformist preconceptions, it would seem that the actual physical evidence of the coal beds strongly favors the theory that the plant accumulations had been washed into place. The coal seams are almost universally found in stratified deposits. The non-carbonaceous sediments intervening between the coal seams are always said to have been water-borne and deposited. The great thickness of some seams and the great numbers of seams in a given locality also constitute prima facie evidence of rapid and cyclic currents carrying and depositing heavy burdens of organic material...
- Space precludes further discussion or the question of coal formation, although many more evidences could be marshalled in favor of the allochthonous theory, such as the frequent splitting of coal seams into two or more independent seams, the many fossil trunks that have been found extending through two or more seams, the 'coal balls' of matted and exceptionally well-preserved fossils, the great boulders often found in coal beds, the frequent grading of coal seams into stratified layers of shale or other sedimentary rock, etc....
- Regardless of the exact manner in which coal was formed, it is quite certain that there is nothing corresponding to it taking place in the world today. This is one of the most important of all types of geologic formations and one on which much of our supposed geologic history been based. Nevertheless, the fundamental axiom of uniformity, that the present is the key to the past, completely fails to account for the phenomena.
Researchers have shown that plant matter can be turned into coal in a matter of hours.
|“||"A rather startling and serendipitous discovery resulted...These observations suggest that in their formation, high rank coals...were probably subjected to high temperature at some stage in their history. A possible mechanism for formation of these high rank coals could have been a short time, rapid heating event." [Six Hours], George R. Hill (Dean of College of Mines & Mineral Industries at the University of Utah), Chemical Technology, May, 1972, pp. 292-296.||”|
- Upright Trees in Coal
- Coal: How Did It Originate? by Harold Coffin
- Snelling, A.A., and J.B. Mackay, Evidence of catastrophic deposition of coals and sediments of the Newcastle coal measures, Proceedings of the 19th Symposium on Advances in the Study of the Sydney Basin, Department of Geology, University of Newcastle, New South Wales, pp. 110-113, 1985.
- Snelling, A.A., and J.B. Mackay, The role of volcanism in the rapid formation of coal seams: The Walloon Coal Measures of Queensland and New South Wales - A case study, Proceedings of the 1985 International Conference on Coal Science, Pergamon Press, Sydney, p. 641, 1985.
- Coal, volcanism and Noah's Flood by Dr Andrew Snelling and John Mackay
- Mackay, J.B., and A.A. Snelling, The 1980 Mount St Helens eruption: The role of volcanism in the formation of coal beds ( A modern analogue of ancient coal measure formation), Proceedings of the 18th Symposium on Advances in the Study of the Sydney Basin, Department of Geology, University of Newcastle, New South Wales, pp. 95-97, 1984.
- ICR The Origin of Coal by Stuart E. Nevins, M.S., Acts & Facts Nov 1, 1976.
- Miners Museum 4 Steps of Coal Formation
- ICR Mt.St.Helens and Catastrophism
- Coal, volcanism and Noah’s Flood by Dr Andrew Snelling and John Mackay, Journal of Creation 1(1):11–29, April 1984.
- The Genesis Flood by John C. Whitcomb and Henry M. Morris. 1994, pp. 162-166.