The diagram illustrates the process of coastal erosion and how it results in the discovery of fossils.
According to the diagram, the coastal erosion happened because of high tides hitting a cliff. Before the occurrence of the high tides and the erosion itself, the cliff stood out at a greater distance and tides were low which means the waves barely touched the cliff. On the other hand, during high tides, the waves would hit the cliff wall. Gradually, the power of these waves become stronger, hitting the cliff harder. This results in damage for lower parts of the cliff and causes the cliff to pull back. The stones from the lower part of the cliff fall into the sea and expose an area in the cliff where the fossils are buried. At the same time, the upper part of the cliff has minimal support. This causes the cliff to fall down, causing coastal erosion and creates a danger zone.
Therefore, if an erosion did not happen, the fossils would still remain buried and will not be discovered. 
The diagram illustrates the process of coastal  
erosion
 and how it results in the discovery of fossils.
According to the diagram, the coastal  
erosion
 happened  
because
 of high  
tides
 hitting a  
cliff
.  
Before
 the occurrence of the high  
tides
 and the  
erosion
 itself, the  
cliff
 stood out at a greater distance and  
tides
 were low which means the waves  
barely
 touched the  
cliff
.  
On the other hand
, during high  
tides
, the waves would hit the  
cliff
 wall.  
Gradually
, the power of these waves become stronger, hitting the  
cliff
 harder. This results in damage for lower parts of the  
cliff
 and causes the  
cliff
 to pull back. The stones from the lower part of the  
cliff
 fall into the sea and expose an area in the  
cliff
 where the fossils  
are buried
. At the same time, the upper part of the  
cliff
 has minimal support. This causes the  
cliff
 to fall down, causing coastal  
erosion
 and creates a  
danger
 zone. 
Therefore
, if an  
erosion
 did not happen, the fossils would  
still
 remain buried and will not  
be discovered
.