Some geologic faults that appear strong and stable, slip and slide like weak faults. Now geologists have provided laboratory evidence showing why some faults that "should not" slip are weaker than ...

Southeastern Pennsylvania, including York County, contains some remarkable geologic history. From rocks representing a fractured supercontinent 550 million years ago to sediment accumulating in a ...

The Earth's crust may have something in common with a lot of people: It tends to be lazy, at least when it comes to moving along certain types of seismic faults, new research says. Using a special ...

The United States has a habit of showcasing its geology. Long before cities and highways showed up, forces beneath the ...

Over the last several weeks, earthquakes have rocked parts of the United States from Alaska to Wednesday morning's quake in Tennessee. The most recent quake registered as a magnitude 4.4, just ...