In Chapters 6 and 7, you learned how limestone rock is created, before being gradually worn down by chemical weathering. In this chapter, we will examine how carbonation of limestone creates a distinct landscape known as karst. Your knowledge of limestone formation and carbonation will make this chapter much easier to understand. The chapter is divided into two sections: the creation of surface karst features and the creation of underground karst features.
KEY WORDS
l Karst l Carbonation l Porous l Pervious l Dissolve l H2
CO3 l CaCO3
l Burren l Marble Arch
(carbonic acid) (limestone)
l Surface features l Underground features l Limestone pavement l Clints l Grikes l Swallow holes l Dry valleys l Caves/caverns l Dripstone features
l Evaporate l Calcite l Stalactites l Stalagmites l Youthful l Mature l Old
LEARNING OUTCOMES
What you MUST know l How limestone is weathered l Two surface features in detail l Two underground features in detail l How to correctly draw and label a diagram of surface and underground features
What you SHOULD know l The three stages of karst landscapes l How to identify karst features on an OS map
What is USEFUL to know l Additional surface and underground features
PATTERNS AND PROCESSES IN THE PHYSICAL ENVIRONMENT 141
