The Long Point–Eureka Heights fault system is a system of

geologic fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

s in

Houston, Texas Houston ( ) is the List of cities in Texas by population, most populous city in the U.S. state of Texas and in the Southern United States. Located in Southeast Texas near Galveston Bay and the Gulf of Mexico, it is the county seat, seat of ...

. It runs beneath the metropolitan area from the southwest to the northeast. The various faults are characterized as

normal fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

s, meaning that the downthrown side is in the direction of the dip of the fault plane. This fault system as well as others located in nearby parts of Texas are believed to have formed millions of years ago during the formation of the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

. No significant earthquakes have occurred on these faults in historic times, but slow movement has been observed.

Gallery

File:Long Point Fault SW Houston.JPG, View is SW at Long Point Road and Lynnview. Upthrown side of the Long Point Fault is to the right. Fault passes to the left of the kiosk. File:Long Point Fault NW Houston.JPG, View is NW at Long Point Road and Lynnview. Long Point Fault passes left-right across the photo center. File:Long Point Fault at Memorial Houston.JPG, View is east on Memorial Drive at W. Forest. Approaching cars are on the downthrown side of the Long Point Fault.

References

Houston: On Shaky Ground

Fault Map (Google)
Geology of Texas Seismic faults of the United States {{tectonics-stub