Marine Fossils, In this PowerPointmarine, we will talk about fossils underwater and how it is related to all science subjects which are biology, and chemistry. physics, and computer science.
2. The remains of past living things
are known as fossils.
The oldest animals in the ocean
are living fossils e.g., Extant
taxon they resemble fossils from
hundreds of millions of years,
they're among the rare survivors
Fossils provide a glimpse of
ancient marine life.
3. Due to the underwater
environment , the bones have
been completely undistributed ,
making locations crucial for
future studies
Shells from marine creatures like
clams , snails , or corals are the
most prevalent fossils
5. How does a
fossil form ?
A fossil is the preserved remains or traces of a dead organism.
The process by which a fossil is formed is called fossilisation.
It’s very rare for living things to become fossilised. Usually after
most animals die their bodies just rot away and nothing is left
behind. However, under certain special conditions, a fossil can
form.
After an animal dies, the soft parts of its
body decompose leaving the hard parts, like the skeleton,
behind.This becomes buried by small particles of rock
called sediment.
As more layers of sediment build up on top, the sediment
around the skeleton begins to compact and turn to rock.
The bones then start to be dissolved by water seeping through
the rock. Minerals in the water replace the bone, leaving a rock
replica of the original bone called a fossil.
6. Fossils give us information about how animals and plants lived in
the past. Once people began to recognize that some fossils looked
like living animals and plants, they gradually began to understand
their evolution.They realized they were the ancestors of today's
plants and animals.
Scientist have two ways to identify which creature does this fossil
belong to.
First way is that we can take the DNA of the fossil and know it’s
type. Some times the fossils represent animals that no longer
exists so we use their DNA as their specification, but some times
the DNA is dead and we can’t find it. So we go to the second
way.
The second way is that we can recognize it by using it’s shape.
Some are easy to recognize and identify ,but some others are hard
to identify their
type.
By studying the fossil record we can tell how long life has existed
on Earth, and how different plants and animals are related to each
other. Often, we can work out how and where they lived and use
this information to find out about ancient environments.
7.
8. During fossilisation, the bone tissue is
modified by various chemical changes
Bone mineral can be decomposed by
ionic substitution, dissolution and
recrystallisation processes
9. A crystal lattice's ability to replace
one or more types of ions with others
of a similar size and charge (for
example, in the olivine series, Fe2+
and Mg2+ can swap places).
Bone undergoes changes at all
scales, from the atomic to the macro.
At the atomic level, the bioapatite
lattice's elements and ions can take
the place of other phases found in
the diagenetic environment. Every
location in the crystal lattice is
susceptible to change. Iron, trace
elements like strontium, uranium,
and/or rare earth elements(REE)
frequently take the place of calcium.
10. Any original biogenic signature
can be replaced with
one reflecting the current
environment by substituting
carbonate ions obtained during
life for carbonate ions obtained
from the environment. which
may be helpful for reconstructing
the paleoenvironment.
• The hydroxide site in the lattice is
frequently replaced by fluoride
and/or chloride
• Under the current diagenetic
conditions, the new mineral phase
must be thermodynamically more
stable than the original bioapatite.
carbonates
union
bonds soluble
form
Union with
external ions
Insoluble
carbonate
salts
11. The amount of fossilisation changes as
collagen is lost. Fluids can now
interact with a larger surface area of
exposed crystallites in bone and move
through it more easily.
Through permineralization, minerals
may precipitate to fill voids or pore
spaces and recrystallization may take
place.
These changes are getting close to
macroscale level change.These
include the use of secondary minerals
like calcite, siderite, and gypsum to
fill pore spaces and cancellous bone.
12.
13. Many palaeontologists use the C-
14 method to determine the age
of fossils.This method is one of
the most accurate.
There is a constant rate of decay
known as a half-life for each
radioactive isotope. Scientists can
determine the age of a fossil by
knowing the rate at which these
isotopes decay.
However, it has a half-life of 5730
years, it is unsuitable for dating
fossils older than 75,000 years.
therefore, potassium-40 is used as
it has a half-life of 1.2 billion years
and is quite abundant in fossils
and surrounding rocks.
14. Only one carbon atom in a trillion
in the atmosphere of Earth is C-14,
and most of it comes from the
Cosmic Ray Action of Nitrogen (N-
14).
C-14 will eventually break down
back into nitrogen after it has
formed.You can measure the
amount of C-14 in dead plants or
animals if you already know how
much C-14 is in living tissue.
By understanding the decay rate of
C-14, which corresponds to a half-
life of 5,370 years, researchers can
ascertain the age of this fossil.
15. Knowing the amount of C-14 from dead tissue is certainly not
easy. Moreover, the production of C-14 in the atmosphere is not
always constant.
Therefore, scientists use the half-life of carbon-14 which is 5,370
years as an ideal benchmark, for those who want to study the last
50,000 years of Earth’s history.
16.
17. Fossils have long been considered
the domain of sedimentary rocks,
but new research demonstrates
that they can be preserved during
the high pressure and
temperature conditions that
produce metamorphic rocks.
18. What happens to
fossils during
compression?
The reason for this is that physical
compression of the rock often leads to
distortion of the fossil.The best fossils
of leaves are found preserved in fine
layers of sediment that have been
compressed in a direction
perpendicular to the plane of the
deposited sediment.
19. The sediment surrounding the
skeleton thickens and begins to
turn to stone.The skeleton
continues to be buried as
sediment is added to the surface
of the sea floor.As the sea floor
sinks, pressure increases in the
lower layers of sediment and it
turns it into hard rock.The
skeleton dissolves and a mould is
formed.
20.
21. The laser probe is raised above
the surface of the item by
specialised software.Two sensor
cameras constantly capture the
shifting length and shape of the
laser line in three dimensions
(XYZ) as it sweeps along the
surface of the item while the laser
probe emits a line of laser light
onto the surface.
22. Also, to include there’s many apps that identify rocks
for example rock identifies minerals pro mineral
scanners. Is an app programmed to identify rocks by
taking a picture of it by your phone find mineral
locations then learning about huge mineral database
23. resources
Fossilization - an overview | ScienceDirectTopics
How to Determine the Age of Fossils with the C-14 Method by
Scientists - NewsyToday (newsy-today.com)
RadioactiveAge Determination - an overview | ScienceDirect
Topics
Potassium 40 - an overview | ScienceDirectTopics
The Learning Zone:What is a fossil? (ox.ac.uk)
https://artsandculture.google.com/entity/compression-
fossil/m08ldr2
https://www.nature.com/articles/ngeo.2007.27
https://www.laserdesign.com/what-is-3d-scanning
