A “lick” is a geographic feature defined by a localized, natural deposit of mineral salts that wildlife consumes to supplement its diet. This site is distinct from major landforms, representing a small but concentrated area of soil, rock, or water with elevated mineral content. The presence of these deposits is an important resource that shapes local ecology and has a long history of interaction with human and animal populations.
Defining the Mineral Lick
A mineral lick, often termed a salt lick, is a place where animals intentionally ingest soil, rock, or water to obtain essential nutrients. The term “lick” is derived directly from the behavior of animals seeking out and consuming the deposits. These sites are typically exposed areas of earth, sometimes appearing as muddy seeps, damp depressions, or sections of mineral-rich rock.
The primary elements concentrated in these deposits are biometals like sodium, calcium, and magnesium, which are often deficient in a herbivore’s plant-based diet. Other significant elements include phosphorus, iron, and trace elements such as zinc and selenium.
The Geological Process of Formation
The creation of a mineral lick is primarily a hydrogeological process involving the movement and concentration of water-soluble minerals. Groundwater flows through the earth, dissolving mineral salts from the surrounding bedrock in a process known as leaching. This mineral-laden water is then brought to the surface through natural springs or areas of persistent seepage.
As the water evaporates upon reaching the surface, it leaves behind a precipitate of concentrated mineral salts in the soil or on the rock face. Certain geological structures, such as areas influenced by ancient volcanic ash deposits, are particularly prone to forming licks with high mineral diversity. The deposits can be classified as hydromorphic, associated with mineral water springs, or lithomorphic, which are exposures of specific mineralized rocks.
Ecological Significance for Wildlife
Mineral licks are a significant component of terrestrial ecosystems, providing necessary elements for the growth and health of many species. Herbivores such as deer, elk, moose, and mountain goats are frequent visitors, relying on the licks to offset nutritional imbalances. Sodium is a particularly sought-after element, as it is often scarce in the vegetation that makes up their diet.
Usage of licks often peaks during the spring and early summer seasons. This timing corresponds with periods of high physiological demand, such as gestation, lactation, and the rapid growth of antlers in male ungulates. The consumption of minerals, especially sodium and magnesium, also helps animals counteract the effects of high potassium levels found in new spring forage.
Historical Context and Regional Usage
These mineral deposits have connected humans and animals for millennia, influencing settlement and hunting patterns. The congregation of game animals at licks made them natural hunting grounds for early human populations and predators. The animal trails leading to these sites were often adopted by early human travelers, in some cases eventually becoming established roads.
A notable historical example is Big Bone Lick in Kentucky, a salt spring that attracted Ice Age megafauna like mammoths and mastodons. This site gained international attention in the 18th century, becoming a subject of paleontological inquiry.