CaCo3 limestone

Carbonation ( chemical weathering) Semer water, Yorkshire Dales Carbonic acid in rainwater dissolves limestone.

CaCo3 + H20 + CO2 Ca(HCO3)2 Limestone + carbonic Acid Calcium bicarbonate

                                                                              

Limestone Pavement                                                                                                                                                                                                                                Limestone Pavements are slabs of rock (clints), separated vertical cracks (grikes). Grikes have developed by weathering and enhanced solution along joints.

Shake Holes A shakehole is a depression in the limestone landscape. They are formed where surface water washes boulder clay down into cracks or fissures in the limestone under the boulder clay.

Resurgent Spring When a stream disappears in a karst area, it works its way down… ….to a level of impermeable rock and reappears as a spring.

During the last ice age huge ice sheets scraped away the soil-covered spurs in many valleys and steep cliffs of bare rock were exposed. Scree slopes of broken rock form below them. Scars

Bedding Planes Malham Cove, Yorkshire Dales The bedding planes are the horizontal layers formed as the rocks were compressed under deposits formed above, about 300 million years ago.

Gorge Trow Gill, Ingleborough. During the meltwater phase of the last ice age, underground streams eroded vast caverns as huge volumes of water travelled through the limestone. Gorge Trow Gill, Ingleborough. Sometimes the roofs of these caverns can collapse.

Dry Valleys During the last ice age the limestone was frozen to great depths. When the ice melted it carved out valleys over the frozen rock. When surface water is able to infiltrate down through the rocks and the dry valleys were left with no surface water.

During the ice age large boulders were carried within the ice sheet During the ice age large boulders were carried within the ice sheet. When the ice melted these boulders were left sitting on the surface. Erratics They are called erratics because they are totally different from the bed rock of the area

Swallow Holes or Sink Holes (smaller). Gaping Gill, Yorkshire Dales. This is where water falls 110m below the ground. It is the UK’s highest underground, unbroken waterfall. Swallow Holes or Sink Holes (smaller). A stream travelling over an impermeable rock will very quickly disappear when it has to travel over limestone. This what pot-holers climb down.