Introduction Geologic materials are used extensively for roads, building, and decoration. Two important forms of rock used in the construction industry are aggregate and dimension stone. Aggregate is sand, gravel, or crushed rock and is used in loose form on roads, between rail road ties, as filler in asphalt and concrete, or decoratively when cemented to walls with some sort of mortar. For decorative purposes, aggregate should be attractive. Concrete aggregate should durable, free of chert and volcanic glass, and low in clay.
Dimension stone is uncrushed rock that has been cut into specified sizes for use in construction.
This field trip will help you discover these uses and reinforce your ability to identify rocks and use the identification to make informed decisions when you are building a home, commercial building, or road. To complete this exercise you will need to go down-town and observe the uses of various rocks. You don't need any equipment other than your eyes, but a hand lens or magnifying glass might be useful. Building names are in approximate order for a walk that starts near Willson and Main and moves east with some excursions onto Babcock and Mendenhall. The last sites are on the MSU Campus.