Do the names of geologic units match between adjacent maps?
Nomenclature describing geologic units evolves over time. Bedrock formations named by geologists 50 or 100 years ago may now have entirely different names. The actual rock described, however, has not changed — only the name has changed (Figure 9). This often occurs when geologists work in widely separated parts of the state, each naming the rocks in their local area. Over time, the extent of mapping expanded until study areas became adjacent. At this point, it was often recognized that each geologist was calling the same rock by a different name. Recent small-scale compilation maps have attempted to standardize formation nomenclature, but many out-of-date names still exist on older maps. So in reading the map be aware of this possibility and carefully read the rock descriptions in each map explanation.
