rock types and landscapes

Rock Types and Landscapes

¼ of the world’s population live in Karst areas (most of this ¼ is found in China)

Formed by Chemical weathering (from rainwater) and erosion

Limestone – Karst Areas – P 92

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Burren – a Karst area

Aran Islands – A Karst Area

Sligo, Leitrim, Fermanagh

Mammoth Caves, Kentucky

Northern Slovenia

Thailand/China – Tower Karst….

…..as seen in Avatar

Lack of rivers/lakes Presence of Swallow Holes – where water disappears

underground Presence of hollows – dolines Presence of underground water (in caves)

Characteristics of Karst Landscapes

Limestone is permeable (water can pass through) Well jointed (vertical “gaps”) Has bedding planes (horizontal “gaps” between layers) Easily chemically weathered

Formation of Karst

Surface Features - Pavement

Clints and Grikes (Gaps)

A Swallow Hole – where a river disappears underground

Dolines – collapsed caverns

Turlough – Disappearing lakes

Turlough – Disappearing lakes

Underground Features - Caves

Undeground Features - Caves

Many cave features are formed by Deposition Rainwater (slightly acidic from the CO2 in the air) dissolves

Calcium Carbonate in Limestone. The dissolved Calcium Carbonate (called Calcite) is deposited

in caves

Cave Features

Stalactites – hang on “tite”

Stalagmites, Pillars/Columns

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Important source of water – many springs in Limestone areas.

Ballygowan water – from limestone area in Limerick

Karst Landscapes - Value

Very important for tourism◦ Caves are tourist attractions (e.g. Ailwee Cave)◦ Unique landscape◦ Planning restrictions mean landscape is kept unspoilt – no

housing estates/McDonalds/Shopping centres allowed◦ Historic features

Karst Landscapes - Value

Unique Ecosystem…. Unusual plants and animals

Karst Landscapes - Value

Engineering difficulties◦ Caves may collapse◦ Industrial Development Restricted ◦ Problems with fresh water contamination due to permeable

nature of landscape – fertiliser, sewerage etc can easily contaminate drinking water supplies

◦ Agricultural development restricted – farming is difficult

Karst Landscapes – Problems

2006 Ordinary Level Question

2008 Higher Level Question