Planet Earth (Earth & Environmental Science V1053y)

Example Proposal #3:

	Dinosaur Killing Meteor?

One of the interesting questions of the history of the
planet is what happened to the dinosaurs that inhabited the Earth
million of years ago. Dinosaurs used to be the dominant  life
form around two hundred twenty five million years ago. They
flourished for- a long time but became extinct around sixty five
million years ago. The reason for their extinction has been the
source of heated debate. Many hypotheses have been given for-
the extinction. Some theories have merit while others seem highly
improbable such as little green beings from Mars retrieving them.
Others propose that volcanoes, bad genes, meteors, global cooling,
global warming and many others wiped out the dinosaurs. 
I know, not one of these theories has been proven beyond a shadow
of a doubt. The only thing that is known for sure is that
dinosaurs were gone by around sixty five million years ago.

A friend of mine explained to me not to long ago that his
professor was convinced that a meteor had hit the earth and wiped
out the dinosaurs shortly thereafter. I must confess that I was
taken aback by this theory because I had never heard of it and
thought it was devised for the reading pleasure of Star Trek
junkies. After all, I am a history major with no real
understanding of geology. My friend was convinced by his teacher-
and in turn was trying to convince me. I decided to conduct my
own investigation to test this hypothesis for the sole reason
that since I have taken geology, this was the only subject that
evoked a passionate response from myself.

Before I began my research, I made a list of what kinds of
evidence I needed to see in order to give this hypothesis merit.
At first, I was clueless but the more I thought about it, the
more I realized that an asteroid impact would probably have the
same effects as nuclear detonations. The first thing that needed
to be found was ground zero, or more precisely, an impact crater.
This crater needed to be huge and deep in order for it to be
consistent with a large object hitting the Earth. The only
problem with this idea was that the planet's outer layer is
mainly water.  I figured that if a crater had not been found by
now, if a meteor had landed, it probably was on water or had hit
land later covered in water. I became despondent over this,
because I knew that seafloors are always changing through
subduction, the impact sight would never be found.

My next idea was the need for a worldwide layer of sediment
that could be telltale sign- of dust clouds that would have
covered the earth and blocked the sun. The dust would have surely
settled to the surface forming a layer in the geology: hopefully one
that could be discerned from others. This layer of soot would
have to be found in different parts of the world that this was 
something planet wide and not just in isolated areas.

The next thing tha thought of was the exploration of
meteor craters on the moon. I  know that the moon is a junkyard
for meteor craters. I figured that an analysis would be helpful.
I wondered if it were possible if a meteor had hit the moon 65
million years ago and the resulting impact had dire consequences 
for much life on Earth. I had no idea what could have caused it
but I theorized that it might have happened because of poisonous
 gases that entered the earth's atmosphere or possibly even change 
in the gravitational forces of the earth and moon that had effects 
on the large animals. Because crocodiles and other reptilians are 
aquatic and some survived, I boldly proposed that the water allowed 
crocodiles to survive while the dinosaurs died.  Also, I figured 
that a crater were found, things could be discovered that had not 
been previously known.  After all, from what I hear from science 
majors and professors, discoveries are usually made accidentally.

Another condition that needed to be satisfied were evidence
from dinosaur fossils. I felt that I could not be convinced
unless I saw direct effects upon the dinosaurs. My best guess as
what to look for were unusually high levels of carbon. This might
show high levels of carbon dioxide and low levels of oxygen.
maybe the dinosaurs suffocated. Another thing that could have
helped would be poison traces in the fossils. This part is
obvious. If enough fossils were found with poison, a 1ink could
be established. I would also try to test this theory by looking
at dinosaur teeth and try to determine what foods they ate and
whether they suffered from malnutrition. I do not see why this
cannot be done because it is possible to look at human teeth
remains and determine the person's diet. 

	Finally, the last piece of evidence and arguably the most
important would be from plant fossils of that time period.  I
would bring any plant remains to a botanist and try to determine
if plants had trouble photosynthesizing or if they died from lack
of sunlight. If some pattern could be established between this
and my other conditions, maybe we could solve the riddle of the
dinosaurs.

	To test my hypothesis, I have assembled the world's most
brilliant, yet open-minded scientists in the world. The first
order of business was to look for the crater.  We have found that
there are 130 documented craters on the Earth but none of them are
big enough for First Science Officer Spock's tricorder readings.
After a while our search becomes in vain and I sadly conclude
that the crater is under the ocean as I had predicted.  However,
the Alvarez team finds a crater at the Yucatan Peninsula in
Mexico that is over a hundred miles wide and underwater.
Suddenly, we have found new hope. The crater was there but this
was only step one.

	I began to analyze layers of sediments preserved in a
valley.  I was looking for a layer that would comprise of soot.
Before we had completed our first day, Mr. Alvarez had announced
his findings that negated the need for us to continue our
analysis.  He found a layer from 65 million years ago.  It
definitely was a small layer that consisted of dust.  Also, there
were high levels of iridium deposits in the layer. Iridium is a
substance that is rare to earth but commonly found on many
meteors.  This was very exciting but I needed to know if this was
a local event or a worldwide one.  After further analysis, iridium
had been found at the K-T boundary in other parts of the world.  I
now had good reason to believe that a meteor had hit the Earth.

	Another interesting development that I never had thought of
was what a meteor would do to rock formations and the evidence 
that it would leave behind.  A man named Bruce Bohor helped the
hypothesis by reporting that shocked quartz was found at crater
sites and around them.  Shocked quartz is the resultant of high
pressure befalling upon ordinary quartz.  It was clear now that a
meteor had indeed hit the Earth because of the iridium and now
the shock quartz.

	The next part of my quest required me to study dinosaur and
plant fossils.  Unfortunately, I was able to find very little
evidence that dinosaurs died directly from a meteor impact.
However, one interesting thing that someone told me was that.
scientists in Canada had found remains on a bluff that was named
Wasoon's Bluff.  The fossil record was clear in that large
dinosaurs were below the iridium line and smaller ones can only
be found above it.  In addition, high carbon levels has been
found in some remains but it is impossible to say why.  The last
part of my quest had to do with plant fossils.  Unfortunately,
this is where I lack any information.  In the books that I have
read I have not been able to find to much evidence or understand
what a lot of things meant. The only thing I have to say on the
subject is that I remember reading that plant life became
radically different after the K-T boundary.

My team and I conducted our experiment the best we could and
our test seems to support the idea of meteor impact that killed
the dinosaurs.  However, there are some things that still need
to be proven that will make this theory 100% positive.  First, there
was definitely a big explosion 65 million years ago that quite
possibly killed the dinosaurs.  However, the question in my
opinion remains open as to if the dinosaurs died because of it.
The fossil record is difficult to interpret. I have not heard
anything to disprove that the dinosaurs may have died before the
impact.  From the fossil record, speculation has given rise to the
possibility that dinosaurs population had diminished dramatically
before the meteor.  This leaves open a chance that the dinosaurs
were already dying when the last of them were killed by the
meteor.  Furthermore, the site in Canada is just one part of the
world.  I am dubious that one meteor could have killed all big
dinosaurs in a short time.  I can only surmise that their may have
been more than one meteor or a gargantuan meteor that split apart
upon entering the Earth's atmosphere.  To be satisfied, more digs
have to be done to establish the worldwide pattern.  Also, I do
not understand how small dinosaurs survived the impact.  It makes
no sense that they survived but never evolved again into 1arge
dinosaurs.  Unfortunately, I was not able to find any information
linking the moon with the Earth.  Maybe I am the first to think of
this concept even though it seems outlandish.  Last but not least,
I think am dubious because if this event did happen, I can only
surmise that it will happen again sooner or later and it is hard
for me to envision an humanless earth.


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