Organic and chemical sedimentary rocks form through different processes. Organic sedimentary rocks, like coal and limestone, form from the remains of living organisms that accumulate and are compressed over time. Chemical sedimentary rocks, like salt deposits and dolostone, form through chemical reactions and precipitation when conditions favor dissolved chemicals in water to solidify and settle as layers of sediment. Fossil fuels like coal, oil, and natural gas were formed from the remains of ancient organisms that lived hundreds of millions of years ago during the Carboniferous Period and became buried and compressed over long periods of time.

2. 

Organic or biological sedimentary rocks are formed by living organisms,
typically when the remains of living organisms build up and are
compacted by sediment. Coal, for example, is made from long-dead
vegetation crushed by thick layers of sediment and chemically altered
through heat and pressure. Most limestone deposits are made from the
shells of microscopic sea organisms. Coral reefs are a beautiful example
of organic sedimentary rocks made by creatures that are still living -corals that build their own homes from calcium carbonate.
Chemical sedimentary rocks, by contrast, form when conditions favor a
chemical reaction or process that causes chemicals dissolved in water
to precipitate, creating a layer of sediment. When water in a salty sea or
lake evaporates, for example, it may leave behind salt and gypsum
deposits. In calcium-rich waters, changes in temperature or acidity may
cause calcium carbonate to precipitate. Accumulation of calcium
carbonate deposits can lead to the formation of limestone. Sometimes
magnesium in water that enters the pores of a limestone rock can
replace the calcium in the rock, turning limestone into another chemical
sedimentary rock called dolostone.

3. The key difference between organic and chemical
sedimentary rocks is
 the process that forms them –
 and often their texture,
 composition and appearance bear mute witness to that
process.
 Geologists can determine whether a sedimentary rock is
organic or chemical by looking at its texture.
 Organic sedimentary rocks contain fossilized remains of
living creatures, since it is these remains that accumulated
to form the rock in the first place.
 Chalk deposits, for example, often contain microscopic
fossils. Salt deposits formed from evaporation, by contrast,
usually contain a mixture of salts, just as you would expect
in a rock that formed from the evaporation of a salty lake.


5. Fossil fuels are fuels formed by natural processes such as anaerobic
decomposition of buried dead organisms. The age of the organisms and their
resulting fossil fuels is typically millions of years, and sometimes exceeds 650
million years.[1] Fossil fuels contain high percentages of carbon and
include coal, petroleum, and natural gas.

7. 


There are three major forms of fossil fuels: coal, oil and natural gas. All
three were formed many hundreds of millions of years ago before the
time of the dinosaurs – hence the name fossil fuels. The age they were
formed is called the Carboniferous Period. It was part of the Paleozoic
Era. "Carboniferous" gets its name from carbon, the basic element in
coal and other fossil fuels.
The Carboniferous Period occurred from about 360 to 286 million years
ago. At the time, the land was covered with swamps filled with huge
trees, ferns and other large leafy plants, similar to the picture above. The
water and seas were filled with algae – the green stuff that forms on a
stagnant pool of water. Algae is actually millions of very small plants.
Some deposits of coal can be found during the time of the dinosaurs.
For example, thin carbon layers can be found during the late
Cretaceous Period (65 million years ago) – the time of Tyrannosaurus
Rex. But the main deposits of fossil fuels are from the Carboniferous
Period.

8. 

This process is called "coalification." During
coalification, peat undergoes several changes
as a result of bacterial decay, compaction,
heat, and time. Peat deposits are quite varied
and contain everything from pristine plant parts
(roots, bark, spores, etc.) to decayed plants,
decay products, and even charcoal if the peat
caught fire during accumulation. Peat deposits
typically form in a waterlogged environment
where plant debris accumulated; peat bogs
and peat swamps are examples. In such an
environment, the accumulation of plant debris
exceeds the rate of bacterial decay of the
debris. The bacterial decay rate is reduced
because the available oxygen in organic-rich
water is completely used up by the decaying
process. Anaerobic (without oxygen) decay is
much slower than aerobic decay.
For the peat to become coal, it must be buried
by sediment. Burial compacts the peat and,
consequently, much water is squeezed out
during the first stages of burial. Continued burial
and the addition of heat and time cause the
complex hydrocarbon compounds in the peat
to break down and alter in a variety of ways. The
gaseous alteration products (methane is one)
are typically expelled from the deposit, and the
deposit becomes more and more carbon-rich as
the other elements disperse. The stages of this
trend proceed from plant debris through peat,
lignite, sub-bituminous coal, bituminous coal,
anthracite coal, to graphite (a pure carbon
mineral).

9. 
Oil and natural gas are formed from the
remains of tiny aquatic animals and
plants. These organisms, once dead, would
have sunk to the bottom of the body of
water they were living in, been covered in
silt and mud, and then started to decay
anaerobic ally. As such, it is reasonable to
assume that the bodies of water that these
micro-organisms were living in were fairly
stagnant, as strong currents in water both
improve aeration and prevent the laying
down of very thick layers of organic
material in the one location.

10. In the graphic on the left, as the
diatoms died they fell to the sea
floor (1). Here they were buried
under sediment and other rock
(2). The rock squeezed the
diatoms and the energy in their
bodies could not escape. The
carbon eventually turned into oil
under great pressure and heat. As
the earth changed and moved
and folded, pockets where oil and
natural gas can be found were
formed (3).
Natural gas is lighter than air.
Natural gas is mostly made up of a
gas called methane. Methane is a
simple chemical compound that is
made up of carbon and
hydrogen atoms. It's chemical
formula is CH4 – one atom of
carbon along with four atoms
hydrogen. This gas is highly
flammable.

11. 







CHOCOLATE FUEL
USED DIAPERS- THE POOPY POTENTIAL
SAWDUST, WODD CHIPS, NUTS AS BIOFUELS
COW POWER-HIGH OCTANE GAS FOR
ELECTRICITY
LEFTOVER FAT AS SOURCE OF BIOFUEL
STYROFOAM CUPS AS A FUEL COMPONENT
ETHANOL
HYDROGEN