coal formed millions of years ago from the remains of what?

Question

about plants

Answer 1

. Coal is formed by heat and pressure over millions of years on vegetation deposited in ancient shallow swamps . It varies in density, porosity, hardness, and reflectivity.

Answer 2

The life-forms on Earth are what is called 'carbon-based'. Plant life, animal life, all has some carbon in it. We have a scientifically anomalous atmosphere, called a 'carbon-reducing' atmosphere (Google that, if you like), where oxygen is present in large amounts.

Oxygen is actually very, very poisonous, and burns extremely enthusiastically, taking everything around with it, and leaving behind nothing but carbon. The only reason we don't burst into flames is that Nitrogen is the predominant element, in free air.

Apply heat to vegetation, animal remains, or even soil, and you get carbon.

Around the perimeter of the Pacific Ocean, in particular, there are places called 'subduction zones'. In these places, the Earth's crust is drawn down into the magma layer below. (The tectonic instability of the 'Pacific Rim' comes from this specific fact. Earthquakes, cyclones, tsunamis, are all driven by this collossal geological recycling system).

The heat is sufficient to both liquefy everything that is pulled in, and also burn it, at the same time, separating it into component elements. The pressure, from the weight of the crust of the earth floating on top, and more from the gravity from the Earth's core, and amount of time the element carbon spends, in the magma layer, determines its hardness, brittleness, purity, and so forth. (This goes for all elements, and applies to all mined stones and metals).

Anywhere we have coal mines now, there were probably vast, inhabited forests, dead, decayed, and finally, swallowed up in an hyper-ancient oceanic subduction zone. Most of the Earth which is now land, once, geological aeons ago, used to be ocean floor.

The British Isles certainly were, with all our limestone, which is basically calcium deposits. (Think shells -- billions of years of compressed shells from microscopic forminifera -- and you have the White Cliffs of Dover).

There are three kinds of coal human beings use most, for industrial purposes:

Bituminous coal: soft, powdery, (very explosive as a powder) a bit oily -- this is the stuff people used to have delivered to their homes, to burn in their hearths, and kitchens, as little as 100 years ago. Now also used in everything from insecticides to dandruff-shampoos.

Anthracite: much harder, denser, even sharp-edged coal, burned by industry now, and ground into powder for explosives. Easy to transport, and grinds up without leaving grease, so has huge industrial uses.

Diamond: pure compressed carbon is clear, and the hardest mineral on Earth. Impure diamond is used for medical instruments -- as a dust it will file anything -- and cutting tools of all shapes and sizes.

Gem-quality diamonds are not particularly rare, but they are held back from the market, by an industry cartel, to drive the prices up. Now, gem-quality diamonds are a black-market currency, funding arms trade from the West to Africa, in particular.

Answer 3

Coal is formed from plant remains that have been compacted, hardened, chemically altered, and metamorphosed by heat and pressure over geologic time.

Answer 4

tropical rainforests where the trees and plants fell into marsh and bogs, they did not rot. Layers and layers built up over time.

Climate changed and they were covered over by sediment or silt, from the sea. Compressed and squeezed, eventually compacting into coal, pockets of gas we trapped in the layers of rock, this is natural gas.

Answer 5

Trees

Answer 6

Coal Formation starts with accumulation of organic matter (bits of dead plants) in a low oxygen setting such as a peat bog. The organic matter accumulates and forms a bed of peat. The peat bed gets buried by other sediments and under heat and pressure begins to transform to a low grade coal - a Lignite. More heat and pressure further metamorphose the lignite into Bituminous coal. Even more heat and pressure metamorphose the bituminous coal into a nice hard shiny Anthracite.

Coal is usually classified into three grades: Lignite, brown coal; Bituminous coal, soft coal; and Anthracite, hard coal. Anthracite is dense, nice and hard, and shiny.

The first step in the formation of coal is the accumulation of plant debris in low oxygen conditions, such as in bogs or swamps.
Peat exposed to heat and pressure from burial beneath other sediments becomes compressed and chemicaly changes into low grade coals such as this lignite, and under further heat and pressure is converted to higher grade coals. The pressure from overlying sediments that bury a peat bed will compact the coal. Peats transform to low grade lignites when they are compressed to about 20% of their original thickness. Lignite typicaly transforms to bituminous coal as it is compressed further and heated to between 100 and 200°C. This drives much of the water and other volitiles from the coal. Longer exposure to elevated temperature will further drive volatiles from the coal, and drive chemical reactions that produce anthracite. Anthracite coals are typicaly compressed to 5-10% of the orginal thickness of the peat bed, and contain less than 10% water and other volatiles.

Coal is often found in beds a meter or more in thickness that are widespread in extent. These are often mined to extract the coal for use as a fossil fuel.

Coal varies considerably, not only in the extent to which it has been metamorphosed, but in the other materials it contains. For example, some coal deposits, such as those of Cretaceous and Tertiary of the western interior of the US, trapped sediment from volcanic ashfalls. Coal can contain not just concentrated plant debris, but also sediments brought in by water, airborne ash falls, elements adsorbed to the carbon of the coal from groundwater, and minerals that form in fractures and spaces in the coal as groundwater flows through it during coalification. Coal seams are typicaly highly variable in composition due to variation in these inputs over short distances.

Answer 7

Carboniferous trees over millions of years.

Answer 8

mainly trees - sometimes coal contains fossils of leaves

Answer 9

Woods

Th

Answer 10

fossils...hence the term, fossil fuels

fossils from carbon based plants etc..