Crushed Stone and Sand and Gravel Aggregates

Construction aggregate is the leading industrial mineral produced in Illinois in terms of value. While most people are familiar with the use of other natural resources such as fuels, metallic minerals, and gems, few are aware of the importance of aggregates. Crushed stone (limestone and dolomite) along with sand and gravel aggregates are used in a wide variety of industries including construction, glass and steel making, paper manufacturing, and environmental remediation. Without crushed stone and sand and gravel there would be no construction aggregates or concrete to build and maintain our homes, schools, and roadways and the basic infrastructure of our society; no agricultural lime to condition soil and control acidity in farmlands; and no scrubber stone to reduce the emissions of pollutants such as sulfur oxide (main cause of acid rain) or mercury from power plants and incinerators.

The need and use of these materials are enormous. Much of our infrastructure including the transportation network, sanitation systems, and general construction is to a large part built with construction aggregates. Nearly 400 tons of aggregate (crushed stone and sand and gravel) are needed to construct an average modern home, and over 38,000 tons are needed to build a mile of interstate highway. An aging transportation infrastructure and booming development, especially in urban and suburban regions, continue to increase the demand for locally available, inexpensive, high-quality aggregate, while new environmental regulations provide a need for high-purity limestone used to clean stack gases from power plants and waste incinerators.

The increased demand for construction aggregates has resulted in a growing need for up-to-date geologic information to ensure the continued availability of high-quality, low-cost construction material throughout the state. According to the Illinois Department of Transportation, a significant number of bridges need repair or replacement, while much of the interstate highway system, and many state and secondary highways and roads, need repairs requiring aggregates. With the depletion of reserves in existing quarries and pits, urban developments on existing reserves, and opposition to opening new mines, the state will be faced with enormous challenges as to how and where it can economically acquire the materials needed for building and rehabilitating its aging infrastructure.

The Industrial Minerals and Resource Economics Section continues the long tradition of conducting research and service related to the geology of construction aggregate and other industrial mineral resources in the state. These efforts have helped ensure that mineral resources in general and construction materials in particular are available locally and inexpensively and provide a basis for conserving resources before they are made inaccessible by development. Intense competition for land and mineral resources has increased the need for current, detailed geologic information ahead of pressing land-use decisions. Geologic research and mapping, the core focus of the ISGS mission, will ensure a balanced approach to land-use planning in order to protect natural resources and the environment now and in the future.

Updated 05/18/2011 SLD