Geomorphology: Transportation and Deposition Processes

Hello everyone. Welcome to the Geoecologist. I'm Dr. Krishnanand and in today's session on the process geomorphology, we're going to learn about the fourth important type of denudation process that is about transportation and deposition together. So, we have not differentiated it into the fourth and the fifth category rather than just the fourth part. So, it can be also differentiated into the fourth type that is transportation and fifth type that is the depositional features, depositional landforms that we study as process part. So, in today's session, let's understand the details of this transportational and depositional denudational processes. But before we go ahead, don't forget to subscribe to our channel and please share the videos with others as well. So now... when we have already learned about the previous three denudational processes, that is basically what weathering, erosion and mass wasting. Today in the fourth part or the last part, we are going to study in this denudational processes, that is the transportation part and the deposition part. So in weathering, the material used to disintegrate at that place. In erosion, it used to transport from one place to the other. And in mass wasting, the gravity influence was there from one place to the other transportation. But if you see here, what happens along this erosion as well as mass wasting there is a transportation of material involved and at the base of the cliff also we saw that there is a deposition involved. So, the last part of this denudational process in geomorphology is the transportation process and the deposition process. So, today we are going to study about transportation and deposition and its various characteristics. So, first thing transportation is basically what once a particle is entrained that is now involved in the process. that is now put upward now it is taken away from that surface so it tends to move as long as the velocity of the medium is high enough to transport the particle horizontally so what happens suppose this is a surface now what happens if there is water or wind action and this particular area has lots of wind and water action and this material is now disintegrated into fragments and what happens water is now taking it away or wind is taking it away so what happens now we understand it all depends on the depends upon the velocity of this particular wind or water that is the capability of this wind and water to hold that material for as long as possible. That is what transportation is involved on the horizontal surface that we know. So this is what happens during the transportation or if there is a slope, it all depends upon that how is the angle of the slope. So that will lead to this transportation accordingly. So when we study transportation, we need to understand that within the medium transportation can occur in different ways. in four different ways. So now we are talking about what? We are talking about within that medium, not outside that medium. So medium was what? Water, air. So if it is water or air, that is the medium. So what are the processes? One is suspension. As we know, this entire particle that is being picked up is suspended in that water medium or maybe air medium. The second is, and also remember in suspension, there is no touching of the surface physically. So it is in the air. or in the water hanging that's why it is suspended right then saltation is there so saltation is what it is basically moving particles in connection to the surface and like this so it is jumping off the surface so small stones pebbles silt bounces along the riverbed so remember it is not suspended but it is bouncing and moving ahead this is called saltation and then what we have is traction so remember traction is what this rolling sliding shuffling action so this is what we say is traction. So these large boulders, pebbles and these rolled along this riverbed. So this is what we know as traction. So traction is along the surface rolling gradually and this jumping off from one place to the other is saltation and then what we know already is solution. So it is now dissolved. So if there are minerals which are dissolved in the water, so they are called solution. So suspension, saltation, traction, solution. So this is what we study as SSTS. right? So, SST, social studies remember? So, SSTs can be remembered in terms of transportation. These processes are important. So, suspension, saltation, traction and solution. So, that process that is suspension, solution, traction, all these processes, what are the main factors that are important here? So, particle weight. So, remember if this particle has too much of weight, it will not be carried for long. Then size. So, if it is larger in size. or it is smaller in size that will be important. Then shape also, it will lead to further movement that is saltation and traction will depend upon the Shape then surface configuration. So that is important that how is this length, width, height of the surface. So how this particular surface is there and is it smooth or it is hard or is it rough or it is stony. So that will all depend upon so that this movement can happen, transportation can happen and then medium time. So if it is air, water, glacier, what is the medium here. So that is important. So hence transportation depends on the appropriate balance of these factors. Now remember particle weight size, shape, configuration of the surface, then what medium is there. All these things carry important roles and these are important factors that determines that how this transportation will be there. Will it be fast? Will it be swift? Will it be smooth or will it be very slow in nature? And what will be the characteristic? So these are the factors that will determine the entire process of transportation. Then the next part of transportation is that material picture. from one place is now being transported. So what happens after transportation? There is a point where this transported material is now dropped and it is deposited. So the next process in denudation is deposition and that is the last part. So deposition is a consequence of erosion that we know that is movement of material from one place to the other. But before erosion what happens? Weathering happens. So the erosional agents lose their velocity. Now remember if water is there or air is there, if its velocity is now decreasing. So what will happen? Its energy is not there to carry the material further. So, it loses on that energy as well. So, what happens? Gradually, this material that is carrying, it's now settling down. So, that is the process of sedimentation that happens or these materials are left here. So, in aeolian process, sand dunes are formed. In the fluvial process, delta is formed as we remember. So, in other words, deposition is not actually the work of any agent. So, remember, it's not about the agent largely. It's about the agent. about whatever agent is there if it has the velocity or the energy enough to carry. So it's more about that. So if it is having that level of energy or that level of particular velocity. So the coarser materials are getting deposited first. So remember because they are coarse, they are heavy, remember the shape configuration. So they will be deposited first. Then finer than that, then finer than that and gradually the most fine. So this is what happens. So what we see is this example of this. Fluvial erosion and deposition. So the first kind of deposition of course of material is called Haber area So remember the foothills of Himalayan region where you have Haber the first part of the slope where coarser green rocks are there coming down The slope then what we have is the Terai that is in the majorly plane of the foothills So that is less in coarseness then further what we have is the coarser alluvium which is called Bangar and then it is Khadar So what we have is BtBk Bk this is is the sequence from Bhabar, Terai, Bangar, Khadar. This is in terms of coarseness. This is in terms of deposition. That's how the entire alluvial planes have formed right from the foothills of Himalaya to the delta area. So that is how we can remember it. So by deposition, depressions get filled up. So remember if there are depressions on our surface, so what happens? The sediments come and deposit here. Remember the geosynclinal theory as well? So geosynclines are further given these sediments from the cratons around. it. So, this is what happens. So, the deposition process is basically filling up these particular depressions on the earth's surface throughout the geological history as we have seen. So, in deposition there is another important thing that we need to understand. It is something called null point hypothesis. So, remember what is this null point hypothesis and how it is linked to deposition. So, deposition occurs when the forces responsible for sediment transportation are no longer sufficient. Remember the velocity, the velocity of the the slope, the energy, these things are no longer sufficient now. So to overcome what? The forces of gravity and friction. So remember if something is being transported, the gravity is always there in action and this friction is always there in action. So what happens? If this friction and gravity is there, it will keep this movement downwards. It will always pull it down. So as long as this has a velocity to move down the slope, till then it's fine. But when it is not there, then automatically it will settle down. downwards. So that is what we say that it is creating a resistance to the motion. What is creating the resistance? The force of gravity and friction and this kind of hypothesis of this deposition is called null point hypothesis. Basically at that particular point, a threshold value till which it can be carried along the slope along the gradient. that point where there is a balance between these two forces that is called null point and after this point it cannot go further it will be deposited here. So that is what null point hypothesis states about this depositional factor that is part of the denudational process. So now when we talk about agents, so what are the agents of erosion as we know? The agents are running water, glaciers, wind, waves, groundwater. The same erosional agents are leading to this depositional agents as well. So what we see is that facilitation of this. this aggradational factor what we know as aggradation. So what happens from here there is a degradation happening. It is moving. This material is now weathered and it is moving and what is happening it was a depression. Now this material is filling up the depression. So this is gaining surface here now. So that is what we say is aggradation happening and factors are the same. Running water, glacier, wind, wave, ground water. These are the important factors here. So let's understand some of the examples of these depositional landforms. So by running water when we say fluvial we see this alluvial fans coming out at the base of this particular hill steep slope this is what we see alluvial fans cones this is one depositional process so alluvial fans then further in the flood plains what do we see there are lots of deposition in the flood plains which are called natural levees that is along the river sides what we understand as these alluvial deposits not just along these particular margins of river so these are sinuous terraces that we understand but these are alluvial deposits which are like this particular embankments which are natural in nature that are called natural levees then what we have is meanders so remember when this particular serpentine movement is there this is called meander and there is something called oxbow lake which is part of the earlier meander which has been now left as the river changed its course so this kind of lake is called oxbow lake these are the features related to all those fluvial deposition in largely the plain areas that is important here Further examples are the deltas. So what we see here is the deposition of these finer sediments here, these silt because it can no longer be carried further. So the river has now broken into different distributaries and these materials are now deposited here. So this delta formation is important here. Then the depositional landforms made by the glaciers as we know is glacial tail, outwash plains and they have these debris and stratified deposits here. So let's learn through these diagrams about moraines as well. So these are another important depositional features as we know they are lateral moraines, medial moraines, end moraines. In detail we are going to learn about the entire glacial landforms. There we are going to discuss about it. So remember the terminology here. These are the depositional features. So if it is in the lateral that is sides it is called lateral moraine. If it is in between it is medial and if it is at the end of this glacier it is end moraines. So these are important here ground moraine, terminal moraine, outwash planes. So this is something brought by by the glacial deposition then further what we have is there is a glacial retreat and then the material that was brought by the glacier has now deposited itself so if it is deposited in this particular fashion what we see here is it is called came and if it is elongated further this heavier elongated material along the flow of the glacier earlier glacier was known as esker so esker are these elongated features and these smaller features are called came so came and eskers are important here Apart from that in glacial areas, we also find these kind of small mounds deposited which are called basket of egg topography. It looks like a basket having several eggs kept. So this kind of topography is basically the deposition of those materials brought by the glacial action earlier way. So that is what we understand as the drumlinoid topography or the blisters. This is called drumlins that is basket of egg topography part of the depositional landforms by the glaciers. Again the depositional landforms made by wind. we already know sand dunes. So what you see here is the crescent shape which is called barken, half crescent or semi crescent is sieve and wind direction along then you have parabolic, then you have transverse, then you have the longitudinal dunes. So transverse dunes and longitudinal dunes various kinds of dunes that we studied. So in detail again we are going to discuss that when we discuss the landforms but today we discussed about a depositional features made by these important agents. So that's where we studied this depositional landforms as well. And at the Another important depositional feature is this lowest deposits as we know this yellow river Hongho in China is called yellow river because of this lowest deposits here, small fine silt sediments. So that is what is important as a depositional feature brought by the Aeolian factor that is wind factor. Now coming to the wave factor. So what you see is different kinds of depositions right from this particular dunes in the beaches to these back shore deposits to these particular areas. So all these deposits are there in the beach area. So beaches and dunes what we see is part of the wave depositions. So, these are another depositions in the denudational process that we study. what we see is this sandbars and these sandbars are now deposited in different shapes here in the bay area and they are known by different names so sandpit, baymouth bar, barrier island, then you have tomolo so that is important in detail we are going to discuss when we discuss the coastal landforms. so the last part of this depositional landforms is when the action of ground water is there so what we have is these pileothems so caves stalagmites stalactites pillars so remember this stalagmite has G it basically means coming out of the ground these depositions that is moving upward from the ground that is called stalagmite and if it is coming from C that is ceiling then it is called stalactite. So, never confuse between the stalactites. So, C and G you have to remember C is for ceiling coming downwards deposition and G is coming upward from the ground and then pillars when these C and G meet. So, this is what is pillars and together these features are called speleothems. So, these are the depositions brought by the underground water action. So, now when we have understood about the transportation and deposition as denoted. processes, various landforms associated to it. So, now it's time that in coming lectures we learn about the theories related to landforms. So, stay tuned. We are going to learn about various theories related to Davis, Penck, Elsie King and others. So, stay tuned. All the best wishes.

So, we have not differentiated it into the fourth and the fifth category rather than just the fourth part. So, it can be also differentiated into the fourth type that is transportation and fifth type that is the depositional features, depositional landforms that we study as process part. So, in today's session, let's understand the details of this transportational and depositional denudational processes. But before we go ahead, don't forget to subscribe to our channel and please share the videos with others as well. So now...

when we have already learned about the previous three denudational processes, that is basically what weathering, erosion and mass wasting. Today in the fourth part or the last part, we are going to study in this denudational processes, that is the transportation part and the deposition part. So in weathering, the material used to disintegrate at that place.

In erosion, it used to transport from one place to the other. And in mass wasting, the gravity influence was there from one place to the other transportation. But if you see here, what happens along this erosion as well as mass wasting there is a transportation of material involved and at the base of the cliff also we saw that there is a deposition involved. So, the last part of this denudational process in geomorphology is the transportation process and the deposition process. So, today we are going to study about transportation and deposition and its various characteristics.

So, first thing transportation is basically what once a particle is entrained that is now involved in the process. that is now put upward now it is taken away from that surface so it tends to move as long as the velocity of the medium is high enough to transport the particle horizontally so what happens suppose this is a surface now what happens if there is water or wind action and this particular area has lots of wind and water action and this material is now disintegrated into fragments and what happens water is now taking it away or wind is taking it away so what happens now we understand it all depends on the depends upon the velocity of this particular wind or water that is the capability of this wind and water to hold that material for as long as possible. That is what transportation is involved on the horizontal surface that we know. So this is what happens during the transportation or if there is a slope, it all depends upon that how is the angle of the slope. So that will lead to this transportation accordingly.

So when we study transportation, we need to understand that within the medium transportation can occur in different ways. in four different ways. So now we are talking about what? We are talking about within that medium, not outside that medium. So medium was what?

Water, air. So if it is water or air, that is the medium. So what are the processes? One is suspension.

As we know, this entire particle that is being picked up is suspended in that water medium or maybe air medium. The second is, and also remember in suspension, there is no touching of the surface physically. So it is in the air. or in the water hanging that's why it is suspended right then saltation is there so saltation is what it is basically moving particles in connection to the surface and like this so it is jumping off the surface so small stones pebbles silt bounces along the riverbed so remember it is not suspended but it is bouncing and moving ahead this is called saltation and then what we have is traction so remember traction is what this rolling sliding shuffling action so this is what we say is traction.

So these large boulders, pebbles and these rolled along this riverbed. So this is what we know as traction. So traction is along the surface rolling gradually and this jumping off from one place to the other is saltation and then what we know already is solution.

So it is now dissolved. So if there are minerals which are dissolved in the water, so they are called solution. So suspension, saltation, traction, solution. So this is what we study as SSTS.

right? So, SST, social studies remember? So, SSTs can be remembered in terms of transportation.

These processes are important. So, suspension, saltation, traction and solution. So, that process that is suspension, solution, traction, all these processes, what are the main factors that are important here?

So, particle weight. So, remember if this particle has too much of weight, it will not be carried for long. Then size. So, if it is larger in size.

or it is smaller in size that will be important. Then shape also, it will lead to further movement that is saltation and traction will depend upon the Shape then surface configuration. So that is important that how is this length, width, height of the surface. So how this particular surface is there and is it smooth or it is hard or is it rough or it is stony.

So that will all depend upon so that this movement can happen, transportation can happen and then medium time. So if it is air, water, glacier, what is the medium here. So that is important. So hence transportation depends on the appropriate balance of these factors.

Now remember particle weight size, shape, configuration of the surface, then what medium is there. All these things carry important roles and these are important factors that determines that how this transportation will be there. Will it be fast?

Will it be swift? Will it be smooth or will it be very slow in nature? And what will be the characteristic? So these are the factors that will determine the entire process of transportation. Then the next part of transportation is that material picture.

from one place is now being transported. So what happens after transportation? There is a point where this transported material is now dropped and it is deposited.

So the next process in denudation is deposition and that is the last part. So deposition is a consequence of erosion that we know that is movement of material from one place to the other. But before erosion what happens?

Weathering happens. So the erosional agents lose their velocity. Now remember if water is there or air is there, if its velocity is now decreasing.

So what will happen? Its energy is not there to carry the material further. So, it loses on that energy as well.

So, what happens? Gradually, this material that is carrying, it's now settling down. So, that is the process of sedimentation that happens or these materials are left here. So, in aeolian process, sand dunes are formed.

In the fluvial process, delta is formed as we remember. So, in other words, deposition is not actually the work of any agent. So, remember, it's not about the agent largely.

It's about the agent. about whatever agent is there if it has the velocity or the energy enough to carry. So it's more about that.

So if it is having that level of energy or that level of particular velocity. So the coarser materials are getting deposited first. So remember because they are coarse, they are heavy, remember the shape configuration. So they will be deposited first. Then finer than that, then finer than that and gradually the most fine.

So this is what happens. So what we see is this example of this. Fluvial erosion and deposition. So the first kind of deposition of course of material is called Haber area So remember the foothills of Himalayan region where you have Haber the first part of the slope where coarser green rocks are there coming down The slope then what we have is the Terai that is in the majorly plane of the foothills So that is less in coarseness then further what we have is the coarser alluvium which is called Bangar and then it is Khadar So what we have is BtBk Bk this is is the sequence from Bhabar, Terai, Bangar, Khadar.

This is in terms of coarseness. This is in terms of deposition. That's how the entire alluvial planes have formed right from the foothills of Himalaya to the delta area.

So that is how we can remember it. So by deposition, depressions get filled up. So remember if there are depressions on our surface, so what happens? The sediments come and deposit here.

Remember the geosynclinal theory as well? So geosynclines are further given these sediments from the cratons around. it.

So, this is what happens. So, the deposition process is basically filling up these particular depressions on the earth's surface throughout the geological history as we have seen. So, in deposition there is another important thing that we need to understand.

It is something called null point hypothesis. So, remember what is this null point hypothesis and how it is linked to deposition. So, deposition occurs when the forces responsible for sediment transportation are no longer sufficient. Remember the velocity, the velocity of the the slope, the energy, these things are no longer sufficient now.

So to overcome what? The forces of gravity and friction. So remember if something is being transported, the gravity is always there in action and this friction is always there in action. So what happens?

If this friction and gravity is there, it will keep this movement downwards. It will always pull it down. So as long as this has a velocity to move down the slope, till then it's fine. But when it is not there, then automatically it will settle down. downwards.

So that is what we say that it is creating a resistance to the motion. What is creating the resistance? The force of gravity and friction and this kind of hypothesis of this deposition is called null point hypothesis. Basically at that particular point, a threshold value till which it can be carried along the slope along the gradient.

that point where there is a balance between these two forces that is called null point and after this point it cannot go further it will be deposited here. So that is what null point hypothesis states about this depositional factor that is part of the denudational process. So now when we talk about agents, so what are the agents of erosion as we know? The agents are running water, glaciers, wind, waves, groundwater.

The same erosional agents are leading to this depositional agents as well. So what we see is that facilitation of this. this aggradational factor what we know as aggradation.

So what happens from here there is a degradation happening. It is moving. This material is now weathered and it is moving and what is happening it was a depression.

Now this material is filling up the depression. So this is gaining surface here now. So that is what we say is aggradation happening and factors are the same. Running water, glacier, wind, wave, ground water.

These are the important factors here. So let's understand some of the examples of these depositional landforms. So by running water when we say fluvial we see this alluvial fans coming out at the base of this particular hill steep slope this is what we see alluvial fans cones this is one depositional process so alluvial fans then further in the flood plains what do we see there are lots of deposition in the flood plains which are called natural levees that is along the river sides what we understand as these alluvial deposits not just along these particular margins of river so these are sinuous terraces that we understand but these are alluvial deposits which are like this particular embankments which are natural in nature that are called natural levees then what we have is meanders so remember when this particular serpentine movement is there this is called meander and there is something called oxbow lake which is part of the earlier meander which has been now left as the river changed its course so this kind of lake is called oxbow lake these are the features related to all those fluvial deposition in largely the plain areas that is important here Further examples are the deltas. So what we see here is the deposition of these finer sediments here, these silt because it can no longer be carried further. So the river has now broken into different distributaries and these materials are now deposited here.

So this delta formation is important here. Then the depositional landforms made by the glaciers as we know is glacial tail, outwash plains and they have these debris and stratified deposits here. So let's learn through these diagrams about moraines as well. So these are another important depositional features as we know they are lateral moraines, medial moraines, end moraines. In detail we are going to learn about the entire glacial landforms.

There we are going to discuss about it. So remember the terminology here. These are the depositional features. So if it is in the lateral that is sides it is called lateral moraine. If it is in between it is medial and if it is at the end of this glacier it is end moraines.

So these are important here ground moraine, terminal moraine, outwash planes. So this is something brought by by the glacial deposition then further what we have is there is a glacial retreat and then the material that was brought by the glacier has now deposited itself so if it is deposited in this particular fashion what we see here is it is called came and if it is elongated further this heavier elongated material along the flow of the glacier earlier glacier was known as esker so esker are these elongated features and these smaller features are called came so came and eskers are important here Apart from that in glacial areas, we also find these kind of small mounds deposited which are called basket of egg topography. It looks like a basket having several eggs kept. So this kind of topography is basically the deposition of those materials brought by the glacial action earlier way. So that is what we understand as the drumlinoid topography or the blisters.

This is called drumlins that is basket of egg topography part of the depositional landforms by the glaciers. Again the depositional landforms made by wind. we already know sand dunes. So what you see here is the crescent shape which is called barken, half crescent or semi crescent is sieve and wind direction along then you have parabolic, then you have transverse, then you have the longitudinal dunes.

So transverse dunes and longitudinal dunes various kinds of dunes that we studied. So in detail again we are going to discuss that when we discuss the landforms but today we discussed about a depositional features made by these important agents. So that's where we studied this depositional landforms as well.

And at the Another important depositional feature is this lowest deposits as we know this yellow river Hongho in China is called yellow river because of this lowest deposits here, small fine silt sediments. So that is what is important as a depositional feature brought by the Aeolian factor that is wind factor. Now coming to the wave factor. So what you see is different kinds of depositions right from this particular dunes in the beaches to these back shore deposits to these particular areas. So all these deposits are there in the beach area.

So beaches and dunes what we see is part of the wave depositions. So, these are another depositions in the denudational process that we study. what we see is this sandbars and these sandbars are now deposited in different shapes here in the bay area and they are known by different names so sandpit, baymouth bar, barrier island, then you have tomolo so that is important in detail we are going to discuss when we discuss the coastal landforms.

so the last part of this depositional landforms is when the action of ground water is there so what we have is these pileothems so caves stalagmites stalactites pillars so remember this stalagmite has G it basically means coming out of the ground these depositions that is moving upward from the ground that is called stalagmite and if it is coming from C that is ceiling then it is called stalactite. So, never confuse between the stalactites. So, C and G you have to remember C is for ceiling coming downwards deposition and G is coming upward from the ground and then pillars when these C and G meet.

So, this is what is pillars and together these features are called speleothems. So, these are the depositions brought by the underground water action. So, now when we have understood about the transportation and deposition as denoted. processes, various landforms associated to it.

So, now it's time that in coming lectures we learn about the theories related to landforms. So, stay tuned. We are going to learn about various theories related to Davis, Penck, Elsie King and others. So, stay tuned.

All the best wishes.

Transcript for:Geomorphology: Transportation and Deposition Processes

Transcript for:
Geomorphology: Transportation and Deposition Processes