All language subtitles for ch 1 pt 3

We have looked at the theory of how the earth was formed.

Now we're going to discuss the theory of how

petroleum is made an accumulated.

In this lecture we are going to talk about types of rocks.

In the rock cycle we have three classifications of rock.

Igneous sedimentary and metamorphic.

We identify these rocks according to rock type.

Of course the you a he has all three classifications

but in this course we will focus on the sedimentary

rock because only in that rock oil is found.

We can further divide sedimentary rock into

additional types carbon it which is limestone and

silicate which is sandstone.

Carbon at rock.

Was formed by chemical composition when the layers

that were laid down to form sedimentary rock

contained remains of living things like shells and coral.

Here's an example of carpeted rock call limestone

and the uae.

Circuit.

Or sandstone was formed when the layers there were

laid down.

Contain silicon particles of varying sizes.

Around leeway you can see examples of sandstone in

the u.

A e most of the oil is found in limestone.

Here is an animation of the rock cycle.

We start with magma from erupting volcanoes that

comes to the surface calls or solidifies into

igneous rock that overtime forms mountains.

The igneous rocks in the mountains are exposed to the

wind and water.

Which begins to break down the rock.

This is called weathering.

Over geological time these particles are

transported by the same wind and water to another location.

This is called erosion.

Eventually these particles and pieces of rock

settle in a quiet place like the bottom of the ocean

where they accumulate into sedimentary layers.

As the layers increase the pressure and temperature

increases on the lower layers causing live with occasion.

A transformation from sedimentary particles into

sedimentary rock.

Little vacation can be formed by compaction which is

a physical process and by cementation which is a

chemical process.

A chemical change within the physical process.

Remember sedimentary rock can be transformed by

these three processes physically.

Or chemically or a combination of both.

Meanwhile as the plates at the margin continue to

move because they are dynamic.

Always moving.

Some of the sedimentary rock is pushed down by

convergent plate movement.

When this subduction which is when one played

pushing down under another occurs the rock is pushed

closer to the mantle.

All that friction of rock pushing and rubbing

against each other causes a lot of heat.

This he changes the minerals in two different shapes

and combinations creating metamorphic rock.

Then because some of this metamorphic rock is pushed

further down it gets so hot it melts forming new magma

and the rock cycle starts over.

Igneous is mostly crystallized are cool parts of magma.

Sedimentary is weathered and eroded igneous rock deposits.

That have formed layers been buried put under heat

and pressure and luther fide.

Physically chemically or both.

Finally metamorphic rock is formed when the played

margin movements causes rock to be pushed down.

And transformed.

As i said before in the oil industry we care mostly

about sedimentary rock because that is where the oil

is where we find the hydrocarbons.

The presence of hydrocarbons and sedimentary rock

is why we search for this type of rock.

But the oil industry is not the only one interested in

sedimentary rock.

It is in this rock that we find all our minerals we find

gypsum used in the building trades.

We find gold silver and copper used in all kinds of

manufacturing as well as jewelry.

The phosphates fuel the petrochemical industry.

In this rock we also find salts a mineral needed for us

to sustain life.

Therefore sedimentary rock is essential to us in our

way of life giving a tremendous economic value.

This is pretty impressive for iraq don't you think.

Here's a chart showing the composition of

sedimentary rock.

As you can see most of it is silt stone mud stone and shale.

These other to the to important ones are limestone

and sandstone.

These are the two that contain most of the oil where

the oil reservoir are found.

Sandstone is generally more important in the united

states mexico.

The gulf of mexico.

Anyway.

They have very little oil producing sandstone.

Now let's go back to the rock cycle for just a moment.

We saw the molten rock appear as magma.

That is then cooled into igneous rock.

It was exposed to weathering and overtime broke down

causing it to crack and separate.

Erosion next moves these cracked and separated

particles a way to some other place causing them to

get separated into smaller and smaller particles.

These particles eventually are deposited on the

bottom of the ocean into sedimentary layers.

As the sedimentary layers are live to fight they form

into sedimentary rock in two different ways.

Some are transformed by deposits which is a physical

change which we call deposition chemical change

which we call precipitation in the physical change.

Sedimentary layers are piled on top of other layers

until they are squeezed compacted and turned into iraq.

Within this physical change you can also get a

chemical change called cementation.

This is where grains in the rock mixed with water

causing them to bond or cement together.

Do not confuse this with precipitation which is also

a chemical change in precipitation change or

chemical change.

Particles are actually formed in carbon.

It's for example particles are formed when carbonic

acid plus calcium ions army mixed with ocean water.

Depending on temperature they solidify back into solids.

Precipitating out of solution and forming layers of

sedimentary rock.

Within physical change in sedimentary rock

formation i want to mention class stick deposition

which is a classification based on particle size.

As you can see in the animation the energy of the water

flow carry sand and sale grains pebbles rocks all

various sizes.

And deposits them on the bottom as the energy decreases.

As the water slows down the heavier particles are

dropped off first with the smaller ones being

carried a little further until all or eventually

dropped and deposited creating plastic deposition.

In this river delta you see these streams and rivers

carrying san sealed and rocks to the ocean.

As these particles get deposited in two layers and

are buried.

Pressure and temperature turned them into

sedimentary rock.

As these particles get deposited into layers and are

buried pressure and temperature turned them into

sedimentary rock.

So let's review in making sedimentary rock you can

have either sandstone or carbon.

Usually when sandstone is converted to sedimentary

rock there is a physical process called deposition.

Further within this deposition you get a chemical

change called see meant asian.

Limestone or carbon and sedimentary rock is formed

by chemical change.

This is called precipitation.

Now using data collected on the ocean floor.

Underneath the earth and at the earth's surface

geologists build maps surface and underground.

They map out the kinds of structures that are present.

They are looking for the formations layers of rock

extending overbroad area.

What kinds of formations are they looking for when

they are looking for or.

Are a couple of basic ones.

On this map the formations are identified.

Let's look at the depositional processes and

environments in more detail.

The first or carbon it's hear you find the dunes.

If you find an ancient don't you will probably say

that the weather there was dry at the time.

It was deposited.

Meandering and braided rivers or river beds can be

identified by the size of the boulders or the rocks

that were deposited by moving water.

If we find big rocks we say the water had high energy.

That the water move fast.

If we find a lot of mixed small ones we say that it was a

big wide river moving slowly.

Here we have an alluvium fan.

Alluvium.

Fans are fan shaped deposits of water transported

material and typically form at the base of a steep slope.

Coarse grained especially at their mouth.

They tend to be relatively fine grained at their edges.

Delta's or river planes are criss crossed with

rivers and streams of slow moving water.

Are large plants like trees and animals flourished.

If you find very small silk particles you will

probably be looking at a lake bottom.

At one time these lakes were underwater.

Something altered the source of this accumulated

water causing it to evaporate.

In these ancient deltas you can find minerals and

hydrocarbons like coal.

In fact if you were a coal mining engineer you would

look for ancient deltas.

Here we have beaches what is interesting about

beaches is that they have been bombarded by steady

waves so the sand grains are almost always the same size.

We call that well sorted deposition.

They are all uniform and size because they have been

ground down by the energy of the wave action over a

long period of time.

When the water subsides and the waves stop the sand on

the beach gets buried compacted or let the fight into

sandstone on.

This is a good reservoir iraq.

Shallow water carbonate platforms like reefs are

very important formations where we can find oil

especially here in the u a e.

Here is an example of a reef.

It is made up of coral an oceanic animals and plants.

After these plants and animals died there remains

were buried and settled into sedimentary layers

luther fight and became sedimentary carbon at rock.

They are formed in tropical or sub.

Tropical shallow oceans were life was plentiful.

This rock also makes very good reservoirs.

Exploration geologist always get very excited when

they find refill formations because these

formations could contain another large oil field.

There are three types of refill.

Platforms are formations where we can find oil.

The first is at the reefs platform edge made of strong

shelves and like banks with high wave energy.

These can form into long reefs that extend along the

ocean sure.

Sometimes they also break off fall into deep water

and are buried.

The second carbonate platform.

Is found the edge of lagoons.

Lagoons are salt water inlets protected from big waves.

The plants and animals their which are different

from the ocean also die and are buried building.

Riffle formations in the mud and shells found the

third type of platform is formed by carbon slopes

made from grains from reefs and banks.

In mud and car minute mudflows.

Here's another reef oceanic plants and animals

animals like clams and other shellfish grow and die.

They're creating reefs from their crushed shells.

They grow out of the water.

Eventually silt and san accumulate allowing trees

and other land plants and animals to grow until these

refs become little islands.

Sop cars are abundant throughout the western region

of the u a e.

They are also important formations for petroleum geologists.

Soccer's are formed when water accumulates on salt

flats and then evaporates.

This leaves a wide layer of sulfates made up of and

hydrate and gypsum.

When these sulfates evaporate out you get three

layers of material and hydride gypsum marsh.

Gypsum crystals.

It is these three layers that define his up go.

What is interesting about a soccer is these hard

layers are imponderable to aisle and form a seal or trap.

Many times we find oil trapped under sub cause again

geologist look for underground suppose.

As we described earlier weathering and erosion

cause sediment to be transported to the oceans.

There at places this sediment builds up at the oceans

edge where it creates a continental shelf.

Eventually the weight of the sediment chefs causing

landslides that form submarine fans.

Fine or sediments are found on the outer fan edge.