1) The document discusses the bi-directional formation of fossil fuels from organic matter deposited in sediments over time. As sediments are buried and subjected to heat and pressure, organic compounds undergo diagenesis and form kerogen. 2) Fossil fuels like oil and gas are derived from tiny marine organisms like algae and phytoplankton that lived in oceans, while coal forms from land plants. The main producers of organic matter are planktonic organisms like phytoplankton and zooplankton. 3) Coal contains longer hydrocarbon chains and is solid, while petroleum contains shorter chains and is liquid. Natural gas has the shortest chains and is in vapor form.

1. ADDIS ABABA UNIVERSITY
College of Natural and Computational Sciences
School of Earth Sciences
Petroleum and Coal Geology Stream
Assignment -4
Compiled by: Yohannes Dessalegn
Id. No.: GSR/3615/13
Submitted to: Balemwal Atnafu (PhD)
Due date: 15/03/2021G.c
Addis Ababa, Ethiopia.
March 2021.
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2. 3/31/2021 1:46 PM
Welcome
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3. “Today’s oil is yesterday’s plankton.”
Presentation outlines
vBi-directional formation of fossil fuels
qDegree of diagenesis
qThe material form
qHydrocarbon chain length
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4. F Bi-directional formation of fossil fuels
most
mainly
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5. v The depth of burial at which most fluid petroleum
hydrocarbons are generated ranges from about a thousand
meters to a few thousand meters with a certain oil
window. As the sediments are buried and subjected to
increased temperatures and pressures, those organic
matter undergo a complex chemical changes. The
compounds resulting from diagenesis are lumped
together under the term kerogen, which are lipid rich.
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6. B. The material form
Coal is formed from land-based plants in bogs and coastal swamps,
while oil and gas are derived from tiny marine organisms, such as
algae and phytoplankton.
Petroleum(crude oil and natural gas) in its forms is derived almost
entirely from organic matter left over from death and decay of plant
and animal microorganisms, mostly marine, and deposited along with
sediments. The great bulk of organic matter is produced in the oceans
by single celled microscopic organisms of various kinds.
The microorganisms that are the most important producers of organic
matter are planktonic(they float in waters of the oceans).
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7. • The greater part are autotrophic (they produce their own
food, mainly by photosynthesis) and thus should be
considered as plants. They are termed phytoplankton. The
main kinds are diatoms, algae of various kinds, and
nannoplankton (extremely small). planktonic
animals(zooplankton) feed on smaller phytoplankton.
Foraminifera are the most important kind of zooplankton.
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8. C. Hydrocarbon chain length
Coal is made of longer chain hydrocarbons while petroleum
is made of short chain hydrocarbons. Hence, coal is solid, oil
is liquid and natural gas is vapor.
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