Which structures are common in younger karst topography? select all that apply. a. caves b. spires c. sinkholes d. sharp towers

Caves, sinkholes are the common structures in younger karst topography. Explanation:

Karst topography is the result of the "dissolution of soluble rocks" like gypsum, limestone, and dolomite. Karst is usually characterized by caves, rocky ground, sinkholes, underground rivers etc. This is due to excavation of underground water on massive limestone and few minerals. The size of Karst varies from microscopic to hundreds of square miles. The topography is found all over the Earth. These are the fresh water sources to large population of the world as it is available as spring waters, ground waters, acquifers.

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