THE UNIFIED SOIL CLASSIFICATION SYSTEM: WHAT YOU SHOULD KNOW BEFORE A CAREER AS A PROFESSIONAL GEOLOGIST

The Unified Soil Classification System (USCS) is a method of classifying soils fundamental to the environmental and engineering geology professions. Despite its importance to the profession, few undergraduate programs include courses about soils. Soil is classified in the USCS using laboratory tests and by visual examination. Visual examination is most common among professionals. Professional Geologists classify soils to differentiate: (1) grain sizes and the approximate percentages of boulders, cobbles, gravel, sand, silt, and clay; (2) the ease with which soil is shaped or molded; (3) moisture, color, and odor; (4) reaction with hydrochloric acid; and (5) consistency and structure. Importantly, the National Association of State Boards of Geology (ASBOG) Fundamentals of Geology (FG) and Practice of Geology (PG) licensing exams include the evaluation of sediments and soils and associated geomorphology, surficial processes, and Quaternary geology as a core competency. This core competency is one of eight domains established by ASBOG that collectively encompass the scientific and practical knowledge needed to become licensed. In this presentation, I will review the art of USCS, discuss soil stratigraphic correlations as they relate to depositional environments, and provide insight into this integral skillset applicable to Professional Geologists, and those seeking licensure, in soil-dominated environments.