I think that the New Madrid Fault line is too far to the east, and the quake was centered just east of Oklahoma City in the town of Sparks, so I don't think the fault line caused it. I added a map below.
Geologists say this weekend's event are nearly 300 million years in the making.
Besides Oklahoma, the earthquake also affected people in the surrounding states of Illinois, Kansas, Arkansas, Tennessee, and Texas.
More than ten aftershocks measuring at east 3.0 magnitude were reported Sunday, in the hours after a 5.6-magnitude earthquake took residents by surprise Saturday night.
The strongest earthquake previously reported in Oklahoma was April 9, 1952, in El Reno, according to the geological survey. Its magnitude was 5.50.
In this video, you can see the New Madrid Fault Line map.