View of geologists pointing to fault in a trench dug across one of the ruptures from the 2014 South Napa earthquake. From front to rear: Alexandra Pickering, Suzanne Hecker, Aaron Page (all USGS). Trench located approximately 3 miles NW of downtown Napa, CA.
What is a "Quaternary" fault?
A Quaternary fault is one that has been recognized at the surface and that has moved in the past 1,600,000 years (1.6 million years). That places fault movement within the Quaternary Period, which covers the last 2.6 million years.
Related
What is a fault and what are the different types?
What is the relationship between faults and earthquakes? What happens to a fault when an earthquake occurs?
Where can I find a fault map of the United States? Is one available in GIS format?
How do I find the nearest fault to a property or specific location?
How do I find fault or hazard maps for California?
Why are there no faults in the Great Valley of central California?
Why are there so many earthquakes and faults in the Western United States?
Why are there so many faults in the Quaternary Faults Database with the same name?

View of geologists pointing to fault in a trench dug across one of the ruptures from the 2014 South Napa earthquake. From front to rear: Alexandra Pickering, Suzanne Hecker, Aaron Page (all USGS). Trench located approximately 3 miles NW of downtown Napa, CA.
Peter Haeussler prepares to measure the offset of a crevasse on the Canwell Glacier.
Peter Haeussler prepares to measure the offset of a crevasse on the Canwell Glacier.
View southeast along the Totschunda fault.
View southeast along the Totschunda fault.
Divisions of geologic time—Major chronostratigraphic and geochronologic units
UCERF3: A new earthquake forecast for California's complex fault system
20 cool facts about the New Madrid Seismic Zone-Commemorating the bicentennial of the New Madrid earthquake sequence, December 1811-February 1812 [poster]
Where's the San Andreas fault? A guidebook to tracing the fault on public lands in the San Francisco Bay region
Quaternary fault and fold database of the United States
Preliminary map showing known and suspected active faults in Colorado
Preliminary map showing known and suspected active faults in Idaho
Preliminary map showing known and suspected active faults in Wyoming
Preliminary map showing known and suspected active faults in western Montana
Related
What is a fault and what are the different types?
What is the relationship between faults and earthquakes? What happens to a fault when an earthquake occurs?
Where can I find a fault map of the United States? Is one available in GIS format?
How do I find the nearest fault to a property or specific location?
How do I find fault or hazard maps for California?
Why are there no faults in the Great Valley of central California?
Why are there so many earthquakes and faults in the Western United States?
Why are there so many faults in the Quaternary Faults Database with the same name?

View of geologists pointing to fault in a trench dug across one of the ruptures from the 2014 South Napa earthquake. From front to rear: Alexandra Pickering, Suzanne Hecker, Aaron Page (all USGS). Trench located approximately 3 miles NW of downtown Napa, CA.
View of geologists pointing to fault in a trench dug across one of the ruptures from the 2014 South Napa earthquake. From front to rear: Alexandra Pickering, Suzanne Hecker, Aaron Page (all USGS). Trench located approximately 3 miles NW of downtown Napa, CA.
Peter Haeussler prepares to measure the offset of a crevasse on the Canwell Glacier.
Peter Haeussler prepares to measure the offset of a crevasse on the Canwell Glacier.
View southeast along the Totschunda fault.
View southeast along the Totschunda fault.