Discovering the Earth’s Layers
If you’ve ever been curious about the geological composition beneath your feet, a newly released geologic map of the contiguous United States offers an unprecedented opportunity to explore this hidden history.
The Creation of the Map
Geologic maps provide insights into the features of an area’s geology, highlighting various types of rocks and sediments, their age, and their distribution. They serve multiple purposes, not only aiding geologists in verifying the age of rock formations but also assisting in the assessment of geological resources such as minerals, as well as understanding natural hazards like earthquakes.
The importance of detailed geologic maps cannot be overstated. The U.S. Geological Survey (USGS) has made significant strides in this regard with its latest offering, The Cooperative National Geologic Map, which is touted as the most detailed map of the lower 48 states to date.
Collaboration and Innovation
The name ‘Cooperative’ aptly reflects the collaborative effort behind this project, which integrated over 100 preexisting geologic maps from both the USGS and various state geological surveys. Despite the extensive data collection traditionally taking many years, innovative automation techniques enabled the team to complete the map and its user interface in just three years.
“Ongoing mapping efforts continually make new discoveries, but past national maps took decades to create while our new method allows us to update our national map faster than ever possible before,”
said Sam Johnstone, a research geologist at the USGS and lead developer of the mapping project.
Exploring Geological Data
This new map empowers users to identify specific locations within the mainland U.S. and delve into the geological data that characterizes them, tracing information about the layers of rock beneath the surface, including formations dating back to the Precambrian era—spanning from 4.5 billion to 541 million years ago, prior to the emergence of life.
Public Accessibility
While geologic maps are invaluable to professionals, this particular map was also designed for public use, welcoming anyone interested in uncovering more about the geological history of the nation, including the age of the rock that lies under their own homes.
“This map provides complete, analysis-ready geologic data for the nation, in a format that is easy to expand going forward,”
stated Joseph Colgan, a USGS research geologist and project leader.
“By providing this map online, we aim to enhance educational engagement and foster a greater public appreciation of geology.”
