Lithology sense of displacement across the zone. In igneous rocks, small-scale structures are mostly observed in lavas such as pahoehoe versus ʻAʻā basaltic flows, and pillows showing eruption within a body of water or beneath ice. Unconsolidated surficial materials may also be given a lithology. This is defined by grain size and composition, and is often attached to an interpretation of how the unit formed. Surficial lithologies can be given to lacustrine, coastal, fluvial, aeolian, glacial, and recent volcanic deposits, among others. Examples of surficial lithology classifications used by the US Geological Survey are, "Glacial Till, Loamy", "Saline Lake Sediment", and
Substance use disorder Substance use disorder A substance use disorder (SUD), also known as a drug use disorder, is a medical condition in which the use of one or more substances leads to a clinically significant impairment or distress. Substance use disorders are characterized by an array of mental, physical, and behavioral symptoms that may cause problems related to loss of control, strain to one's interpersonal life, hazardous use, tolerance, and withdrawal. Drug classes that are involved in SUD include alcohol, opioids, stimulants, tobacco, hallucinogens, phencyclidine, inhalants, and sedatives. Worldwide 275 million people were estimated to have used an illicit drug in 2016.