Karst Topography

KarstKarst TopographyTopography

KarstKarst TopographyTopographyA form of landform denudation based almost A form of landform denudation based almost exclusively on carbonation (chemical exclusively on carbonation (chemical weathering)weathering)

Chemical weathering of joints and fractures can create Chemical weathering of joints and fractures can create huge subsurface cavitieshuge subsurface cavities

Requirements for formation [Note connection Requirements for formation [Note connection to hydrologic cycle]to hydrologic cycle]

WaterWaterLimestone must be at least 80% calcium carbonate Limestone must be at least 80% calcium carbonate (CaCO(CaCO33))Limestone must have a complex network of joints for Limestone must have a complex network of joints for water to pass throughwater to pass throughA zone of aeration (allows for water to flow)A zone of aeration (allows for water to flow)

Vegetation cover providing different acidsVegetation cover providing different acids

Features of Features of KarstKarst landscapeslandscapesSinkholesSinkholesCaves and CavernsCaves and Caverns

Poor surface drainagePoor surface drainageDisappearing surface streamsDisappearing surface streamsUnderground riversUnderground rivers

SinkholesSinkholesDepressions in the Depressions in the landscape landscape Formed by water Formed by water draining through a draining through a jointjointDolineDoline: A sinkhole : A sinkhole that intersects the that intersects the water table, water table, forming a small lakeforming a small lakeCollapse Sinkhole: Collapse Sinkhole: sinkhole breaks sinkhole breaks through roof of through roof of underlying cavernunderlying cavern

Devil’s Sinkhole

Caves and CavernsCaves and CavernsCaverns typically form near the water Caverns typically form near the water table, such that fluctuations in the level of table, such that fluctuations in the level of the water table alternately inundate and the water table alternately inundate and drain themdrain them

PhreaticPhreatic zonezone

Lowering of the water table (or uplift) later Lowering of the water table (or uplift) later keeps them drainedkeeps them drainedDripstone: stalactites, stalagmites, Dripstone: stalactites, stalagmites, columnscolumns

ColumnColumn

StalactiteStalactite

StalagmiteStalagmite