Glaciokarst is a geological term that refers to a specific type of karst landscape that been influenced significantly by past glacial activity. [1]
Karst landscapes consist of distinctive surface and subsurface landforms. These landforms are a result from dissolution of soluble rocks like limestone, gypsum or dolomite by water. [2] In the case of glaciokarst, the karst landscape has been shaped by the action of glaciers due to glacial erosion, deposition or other processes that directly impact the soluble rocks in the area. This unique blend of processes results in a landscape that not only documents the deep history of glaciation but also exemplifies the resilience and adaptability of the Earth's geological systems. Examples of glaciokarst landscapes are found in the Western Alps or the Eastern Alps such has Tennengebirge, Dachstein Mountains and even the Altai Mountains.
Glaciokarst landscapes form through a interactions between ice and certain types of rock, like limestone, gypsum, or dolomite, that are able to dissolve in water. When vast glaciers move over the land, they shape it by carving valleys and other glacial features. As these glaciers melt, the water formed contains a mild acid that can dissolve these specific rocks, creating gaps and hidden spaces underground. Over time, the combination of glacial sculpting and rock dissolution produces distinct landforms such as sinkholes and caves within the regions affected by glaciers. This creates a unique landscape showcasing the combined effects of glacier movement and the gradual erosion of rock, offering a fascinating array of features for exploration and study.
An example of a formation of a glaciokarst is the glaciokarst of the Velež Mountain. This landscape showcase a karst terrain significantly affected by glacial processes during the Pleistocene period. This landscape includes valley glaciers and a plateau glacier, primarily located on the northern slopes. The northern slopes exhibit features shaped by glacial erosion, presenting cirques, pavements, and roches moutonnées covered with small-scale karst features. While in the lower regions of the Velež Mountain, formed significant moraine ridges, lateral moraines, breach-lobe moraines, and smaller recessional moraines, varying in composition and heights. The absence of valley discharge and the presence of indicators of glacial erosion hint at a pattern of vertical drainage of sub-glacial waters into the karst landscape. The outwash fans that filled some hollow areas displayed a change in the kind of dirt they carried, going from rough near the ice's edge to finer stuff as they moved away. This change shows how much glaciers shaped the mountain's land and water pathways.
Glaciokarst landscapes have an array of unique features resulting from the fusion of glacial and karstic processes. Typical features found in glaciokarst landscapes may include glacially carved valleys, sinkholes formed by the dissolution of bedrock, and ice-contact features. [3] Glaciokarsts encompass various classifications based on multiple criteria. [4] These classifications include distinctions regarding the presence of meltwater, the types of karstic rocks involved, proximity to the Equator, the relationship between glaciers and karst formations, the geographical location of the glaciokarsts, and the rate of glaciation. [5] Glaciokarsts are predominantly composed of limestone but can also form on marble, dolomite, and gypsum. Structurally, they are categorized into Alpine or continental types, and geosyncline or tabular types. They can exist in marine or terrestrial environments, each with varying levels of precipitation and ice cover impacting the karst formations. The interaction between the processes of glaciation and karstification can create intriguing geological formations and landscapes.