Lithological modeling

Granitic morphological system

Granite is an igneous rock mainly made of quartz, mica, and feldspar. It rises to the surface because of the tectonic movements. This modeling is a consequence of how it is made and how it behaves. It leads to different landforms:

• Dome: The granite rises and it erodes dome shaped.

• Spheroidal weathering: these granitic structures are caused by the erosion of the dome. It provokes cracks that divide the block into smaller ones which appear organized stacked up

• Balanced rock: the rock breaks and starts rounding collapsing the structure, so the stones on the top, are in balance over the rest of the rock.

• Pinnacle: rock structure tower shaped.

• Flat stone: big, smooth, plain and long rock formed because of the breaking down of granites.

• Inselberg: some of them also have a granitic origin.

• Tafoni: Also formed in granitic-origin rocks thanks to different chemical processes.

• Tor: Water breaks the granitic rock down when it goes through the cracks that appear on it.

Karst morphological system

Geological formation shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rock. The name comes from the Karts region in Slovenia. In Spain, karst landscapes can be seen in Cuenca, Antequera…

  External Karst

•  Limestone pavements

•  Pit cave: vertical well that appears on carbonate rocks (water erosion).

• Upwelling: Water comes out the galleries through these areas.

•  Sinkhole or doline: Circular depression because of the dissolution of the top part. It can also be formed by a cave collapsing due to materials weight.

• Polje: Bigger hollow that has a plain bottom.

• Uvala:  Collection of multiple smaller individual sinkholes.

• Tormo: Vertical carbonate rock reliefs formed because of the dissolution of the rock bottom part.

• Torcal (tower karst): stone stacked up.

Internal Karst

Water seeps into the caves and floods the galleries as a consequence of the rise or fall of the water level. When it reaches the phreatic zone, the water accumulates and starts to run horizontally.

• Stalactites and stalagmites: type of rock formations that hangs from the ceiling of caves (the first ones) or rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings.

• Pit cave: vertical well which leads into deep caves and galleries.

• Column: union of a stalactite and a stalagmite.

• Travertine: Form of limestone originated when water evaporates and the bicarbonate precipitates.

Coastal Morphological Systems

This type of modeling doesn´t rely on the clime. It depends on other factors such as the waves, the tides and the currents.

1. Agents: Water is the main agent. It can´t produce erosion unless it carries different materials.
2. Processes: Intense chemical weathering (thanks to the presence of water) and biological weathering (for instance: limpets, a type of mollusk, stick to rocks and erode them). The erosion caused by the waves forms:

• Cliff: Sea shores with steep slopes. Water undermines the bottom part of the rock, so it loses balance and breaks. Gravity acts and the materials fall down forming an abrasion platform.

•  Arc: It is formed when the waves crash against a land rise and change their course, heading towards an area on the walls that they will erode.
• 
  

• 
  
• 
  
• Stack: Formed by the extreme erosion of an arc. It is a vertical column of rock in the sea near a coast.
• 
  

• 
  
• 
  
• Caves: they are formed because of the constant crash of the waves against a certain point on the rock.

   Landforms caused by transport and sedimentation:

•   Beach: Places where the materials brought to the coast by the waves are sedimented. It is divided into three different parts:
• 
  

                    -  Foreshore: It´s the closest area to the sea and it floods with the high tide.

                    -  Berm: mound that separates the foreshore and the backshore.

                    -  Backshore: Furthest area from the sea, with some vegetation.

                    - Dunes: Originated by the action of the wind on the deposited materials.

• Bays and coves: These areas are more protected from the waves than beaches. They have a bigger curvature than beaches.
• 
  

• 
  
•   Sandspit: It´s a type of bar or beach parallel to the coast formed by the accumulation of materials because of the process of longshore drift. This process consists of the transport of sediments by waves along the coast at an specific angle in relation to the shore line, but they go back parallel to it, in the direction of the maximum slope. Sandspits create lagoons.

• 
  
•  Marsh: Type of wetland (flat area saturated with seawater).
• 
  

• 
  
• Tombolo: Islet attached to the coast by a sand bar.

• 
  
• Coral reef: Underwater structures made from calcium carbonate secreted by corals. Corals grow in warm very oxygenated and clean seas.