KEY TERMS

• EROSION = the wearing away of rock, involving movement
• deposition = when the ice carrying the material melts, the material if deposited (dropped) on the valley floor
• transportation = glacier moves material over large distance
• plucking = happens when meltwater at the base, back and the side of the glacier freezes onto the rock, when the glacier moves forward it plucks the rock out.

  2 signs of plucking are :

  1. jugged rocks
  2. scree (loose rocks on the mountainside)
• abrasion = bits of rocks stuck in the ice grind against the bedrock below the glacier, wearing it away.

  sign of abrasion :

  striations (marks on the bedrock)
• Pleistocene = the epoch (an event or a time that begins a new period or development) from 2.6 million yrs ago- 11,700 yrs ago (includes the ice age)
• holocene = current epoch (an event or a time that begins a new period or development) began 11 700 yrs ago
• quaternary period = current period, contains both the Pleistocene and the holocene
• u - shaped valley/glacial trough = eroded by glaciers
• v - shaped valley = erosion by rivers/lakes
• striation = a series of long, straight, parallel lines or grooves scratched onto a bedrock surface by rock fragments lodged in the base of a moving glacier
• moraine = deposit of unsorted material left behind when a glacier melts
• corrie/cwm/cirque = They form when the glacier deepens an existing hollow through freeze-thaw, As the ice moves down the mountain does so in a circular motion which further deepens the hollow, leaving a lip at the end.

  
• corrie lake/tarn = Due to less erosion at the front of the glacier a corrie lip is formed. After the glacier has melted a lake forms in the hollow.

  
• arete = is a knife-edge ridge. It is formed when two neighbouring corries or u shaped valleys run back to back. As each glacier erodes either side of the ridge, the edge becomes steeper and the ridge becomes narrower

  
• pyrimidal peak = formed where three or more corries and arêtes meet. 
• till = all material deposited by a glacier
• rotational slip = Movement of the ice out of the corrie in a circular motion
• moraine = material left behind by a moving glacier.
• outwash = material carried away from a glacier by meltwater and deposited beyond the moraine.
• erratic = A glacial erratic is a glacially deposited rock differing from the type of rock native to the area in which it rests

  
• contour lines =  a line drawn on a topographic map to indicate ground elevation or depression (pressure)
• sedimentary rock = formed from pre-existing rocks or pieces of once-living organisms. 

  e.g. sandstone and limestone
• igneous rocks = form when hot, molten rock crystallizes and solidifies

  e.g. granite and basalt
• metamorphic rock = started out as some other type of rock, but have been substantially changed from their original igneous, sedimentary, or earlier metamorphic form. 

  e.g. schist and marble
• relief/topography = the term used for the differences in height from place to place on the land's surface 
• tectonice = relating to the structure of the surface of the earth and the way it is formed, changed, and moved by forces inside it: the motion of the earth's tectonic plates